diff --git a/.eslintrc.js b/.eslintrc.js
index ce319a3d37f558..b928c441e32463 100644
--- a/.eslintrc.js
+++ b/.eslintrc.js
@@ -1,10 +1,9 @@
 const path = require('path');
 
 module.exports = {
-  // So parent files don't get applied
-  root: true,
+  root: true, // So parent files don't get applied
   globals: {
-    preval: false,
+    preval: false, // Used in the documentation
   },
   env: {
     es6: true,
@@ -12,13 +11,13 @@ module.exports = {
     node: true,
     mocha: true,
   },
-  extends: ['plugin:import/recommended', 'airbnb'],
+  extends: ['plugin:import/recommended', 'airbnb', 'prettier'],
   parser: 'babel-eslint',
   parserOptions: {
     ecmaVersion: 7,
     sourceType: 'module',
   },
-  plugins: ['babel', 'import', 'jsx-a11y', 'mocha', 'material-ui'],
+  plugins: ['babel', 'mocha', 'material-ui'],
   settings: {
     'import/resolver': {
       webpack: {
@@ -27,16 +26,35 @@ module.exports = {
     },
   },
   rules: {
-    'linebreak-style': 'off', // Don't play nicely with Windows
-    'arrow-body-style': 'off', // Incompatible with prettier
-    'arrow-parens': 'off', // Incompatible with prettier
-    'object-curly-newline': 'off', // Incompatible with prettier
-    'function-paren-newline': 'off', // Incompatible with prettier
-    indent: 'off', // Incompatible with prettier
-    'implicit-arrow-linebreak': 'off', // Incompatible with prettier
-    'space-before-function-paren': 'off', // Incompatible with prettier
-    'no-confusing-arrow': 'off', // Incompatible with prettier
-    'no-mixed-operators': 'off', // Incompatible with prettier
+    // Incompatible with prettier
+    'react/jsx-wrap-multilines': 'off',
+    'react/jsx-one-expression-per-line': 'off',
+    'react/jsx-indent': 'off',
+
+    // It's buggy
+    'react/jsx-curly-brace-presence': 'off',
+    'react/require-default-props': 'off',
+    'jsx-a11y/label-has-associated-control': 'off',
+    'jsx-a11y/label-has-for': 'off', // deprecated
+
+    // Strict, airbnb is using warn
+    'no-console': 'error',
+    'no-alert': 'error',
+    'react/no-danger': 'error',
+
+    // Strict, airbnb is using off
+    'react/no-direct-mutation-state': 'error',
+    'react/sort-prop-types': 'error',
+
+    // Airbnb use error
+    'no-param-reassign': 'off',
+    'no-prototype-builtins': 'off',
+    'react/forbid-prop-types': 'off',
+    'react/destructuring-assignment': 'off',
+    'react/no-find-dom-node': 'off',
+
+    'jsx-a11y/no-autofocus': 'off', // We are a library, people do what they want.
+    'prefer-destructuring': 'off', // Destructuring harm grep potential.
     'consistent-this': ['error', 'self'],
     'max-len': [
       'error',
@@ -46,16 +64,7 @@ module.exports = {
         ignoreUrls: true,
       },
     ], // airbnb is allowing some edge cases
-    'no-console': 'error', // airbnb is using warn
-    'template-curly-spacing': 'off', // Crash
-    'prefer-destructuring': 'off', // airbnb is using error. destructuring harm grep potential.
-    'no-alert': 'error', // airbnb is using warn
-    'no-param-reassign': 'off', // airbnb use error
-    'no-prototype-builtins': 'off', // airbnb use error
-    'operator-linebreak': 'off', // airbnb use error
-
-    // It would be better to enable this rule, but it might slow us down.
-    'import/no-extraneous-dependencies': 'off',
+    'import/no-extraneous-dependencies': 'off', // It would be better to enable this rule.
     'import/namespace': ['error', { allowComputed: true }],
     'import/order': [
       'error',
@@ -64,12 +73,6 @@ module.exports = {
         'newlines-between': 'never',
       },
     ],
-
-    'react/jsx-indent': 'off', // Incompatible with prettier
-    'react/jsx-closing-bracket-location': 'off', // Incompatible with prettier
-    'react/jsx-wrap-multilines': 'off', // Incompatible with prettier
-    'react/jsx-indent-props': 'off', // Incompatible with prettier
-    'react/jsx-one-expression-per-line': 'off', // Incompatible with prettier
     'react/jsx-handler-names': [
       'error',
       {
@@ -78,26 +81,19 @@ module.exports = {
         eventHandlerPropPrefix: 'on',
       },
     ],
-    'react/jsx-curly-brace-presence': 'off', // airbnb use error, it's buggy
-    'react/forbid-prop-types': 'off', // airbnb use error
-    'react/require-default-props': 'off', // airbnb use error, it's buggy
-    'react/destructuring-assignment': 'off', // airbnb use error
     'react/jsx-filename-extension': ['error', { extensions: ['.js'] }], // airbnb is using .jsx
-    'react/no-danger': 'error', // airbnb is using warn
-    'react/no-direct-mutation-state': 'error', // airbnb is using off
-    'react/no-find-dom-node': 'off', // airbnb use error
-    'react/sort-prop-types': 'error', // airbnb use off
-
     'material-ui/docgen-ignore-before-comment': 'error',
-
     'mocha/handle-done-callback': 'error',
     'mocha/no-exclusive-tests': 'error',
     'mocha/no-global-tests': 'error',
+    'mocha/no-identical-title': 'error',
+    'mocha/no-nested-tests': 'error',
     'mocha/no-pending-tests': 'error',
+    'mocha/no-return-and-callback': 'error',
+    'mocha/no-sibling-hooks': 'error',
     'mocha/no-skipped-tests': 'error',
-
-    'jsx-a11y/label-has-associated-control': 'off',
-    'jsx-a11y/label-has-for': 'off',
-    'jsx-a11y/no-autofocus': 'off', // We are a library, people do what they want.
+    'mocha/no-top-level-hooks': 'error',
+    'mocha/prefer-arrow-callback': 'error',
+    'mocha/valid-suite-description': 'error',
   },
 };
diff --git a/docs/src/modules/components/Demo.js b/docs/src/modules/components/Demo.js
index 79f3c6414f2cd8..1ab5fd2fc11c2c 100644
--- a/docs/src/modules/components/Demo.js
+++ b/docs/src/modules/components/Demo.js
@@ -235,16 +235,14 @@ class Demo extends React.Component {
       });
     }
 
-    this.setState(prevState => {
-      return {
-        /**
-         * if the the same code type is open,
-         * toggle the state, otherwise if it is
-         * another code type always open it. i.e, true
-         */
-        codeOpen: this.props.codeVariant === codeVariant ? !prevState.codeOpen : true,
-      };
-    });
+    this.setState(prevState => ({
+      /**
+       * if the the same code type is open,
+       * toggle the state, otherwise if it is
+       * another code type always open it. i.e, true
+       */
+      codeOpen: this.props.codeVariant === codeVariant ? !prevState.codeOpen : true,
+    }));
   };
 
   handleClickCodeOpen = () => {
diff --git a/docs/src/modules/utils/helpers.test.js b/docs/src/modules/utils/helpers.test.js
index f4db78a4a17812..7e654f497a4348 100644
--- a/docs/src/modules/utils/helpers.test.js
+++ b/docs/src/modules/utils/helpers.test.js
@@ -20,7 +20,7 @@ const styles = theme => ({
   formContro
 `;
 
-  it('generates the right npm dependencies', () => {
+  it('should handle @ dependencies', () => {
     assert.deepEqual(getDependencies(s1), {
       '@foo-bar/bip': 'latest',
       '@material-ui/core': 'latest',
@@ -30,7 +30,7 @@ const styles = theme => ({
     });
   });
 
-  it('generates the right npm dependencies', () => {
+  it('should handle * dependencies', () => {
     const s2 = `
 import React from 'react';
 import PropTypes from 'prop-types';
@@ -56,7 +56,7 @@ const suggestions = [
     });
   });
 
-  it('generates the right npm dependencies', () => {
+  it('should support next dependencies', () => {
     assert.deepEqual(getDependencies(s1, 'next'), {
       '@foo-bar/bip': 'latest',
       '@material-ui/core': 'latest',
@@ -66,7 +66,7 @@ const suggestions = [
     });
   });
 
-  it('generates the right npm dependencies', () => {
+  it('should support direct import', () => {
     const s3 = `
 import 'date-fns';
 import React from 'react';
diff --git a/docs/src/pages/demos/autocomplete/IntegrationAutosuggest.js b/docs/src/pages/demos/autocomplete/IntegrationAutosuggest.js
index 0e0341b1033f96..1c848d920cdc2c 100644
--- a/docs/src/pages/demos/autocomplete/IntegrationAutosuggest.js
+++ b/docs/src/pages/demos/autocomplete/IntegrationAutosuggest.js
@@ -74,8 +74,8 @@ function renderSuggestion(suggestion, { query, isHighlighted }) {
   return (
     <MenuItem selected={isHighlighted} component="div">
       <div>
-        {parts.map((part, index) => {
-          return part.highlight ? (
+        {parts.map((part, index) =>
+          part.highlight ? (
             <span key={String(index)} style={{ fontWeight: 500 }}>
               {part.text}
             </span>
@@ -83,8 +83,8 @@ function renderSuggestion(suggestion, { query, isHighlighted }) {
             <strong key={String(index)} style={{ fontWeight: 300 }}>
               {part.text}
             </strong>
-          );
-        })}
+          ),
+        )}
       </div>
     </MenuItem>
   );
diff --git a/docs/src/pages/demos/buttons/TextButtons.js b/docs/src/pages/demos/buttons/TextButtons.js
index c49dcf881cff9f..e8d40843bf5ce3 100644
--- a/docs/src/pages/demos/buttons/TextButtons.js
+++ b/docs/src/pages/demos/buttons/TextButtons.js
@@ -32,11 +32,11 @@ function TextButtons(props) {
       <input
         accept="image/*"
         className={classes.input}
-        id="flat-button-file"
+        id="text-button-file"
         multiple
         type="file"
       />
-      <label htmlFor="flat-button-file">
+      <label htmlFor="text-button-file">
         <Button component="span" className={classes.button}>
           Upload
         </Button>
diff --git a/docs/src/pages/demos/progress/CircularIntegration.hooks.js b/docs/src/pages/demos/progress/CircularIntegration.hooks.js
index 0138c1d1d4219f..eed9351280b35d 100644
--- a/docs/src/pages/demos/progress/CircularIntegration.hooks.js
+++ b/docs/src/pages/demos/progress/CircularIntegration.hooks.js
@@ -50,11 +50,12 @@ function CircularIntegration() {
     [classes.buttonSuccess]: success,
   });
 
-  React.useEffect(() => {
-    return () => {
+  React.useEffect(
+    () => () => {
       clearInterval(timer);
-    };
-  }, []);
+    },
+    [],
+  );
 
   function handleButtonClick() {
     if (!loading) {
diff --git a/docs/src/pages/demos/progress/DelayingAppearance.hooks.js b/docs/src/pages/demos/progress/DelayingAppearance.hooks.js
index f808284759165b..ee5adb1e32418f 100644
--- a/docs/src/pages/demos/progress/DelayingAppearance.hooks.js
+++ b/docs/src/pages/demos/progress/DelayingAppearance.hooks.js
@@ -25,11 +25,12 @@ function DelayingAppearance() {
   const [query, setQuery] = React.useState('idle');
   let timer = null;
 
-  React.useState(() => {
-    return () => {
+  React.useState(
+    () => () => {
       clearTimeout(timer);
-    };
-  }, []);
+    },
+    [],
+  );
 
   function handleClickLoading() {
     setLoading(prevLoading => !prevLoading);
diff --git a/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.hooks.js b/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.hooks.js
index f5b750d26387b2..811b702cee5ce0 100644
--- a/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.hooks.js
+++ b/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.hooks.js
@@ -56,13 +56,11 @@ function HorizontalLabelPositionBelowStepper() {
   return (
     <div className={classes.root}>
       <Stepper activeStep={activeStep} alternativeLabel>
-        {steps.map(label => {
-          return (
-            <Step key={label}>
-              <StepLabel>{label}</StepLabel>
-            </Step>
-          );
-        })}
+        {steps.map(label => (
+          <Step key={label}>
+            <StepLabel>{label}</StepLabel>
+          </Step>
+        ))}
       </Stepper>
       <div>
         {activeStep === steps.length ? (
diff --git a/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.js b/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.js
index 85fc0cdf692bf7..ce63480c8c9ca7 100644
--- a/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.js
+++ b/docs/src/pages/demos/steppers/HorizontalLinearAlternativeLabelStepper.js
@@ -68,13 +68,11 @@ class HorizontalLabelPositionBelowStepper extends React.Component {
     return (
       <div className={classes.root}>
         <Stepper activeStep={activeStep} alternativeLabel>
-          {steps.map(label => {
-            return (
-              <Step key={label}>
-                <StepLabel>{label}</StepLabel>
-              </Step>
-            );
-          })}
+          {steps.map(label => (
+            <Step key={label}>
+              <StepLabel>{label}</StepLabel>
+            </Step>
+          ))}
         </Stepper>
         <div>
           {this.state.activeStep === steps.length ? (
diff --git a/docs/src/pages/demos/steppers/HorizontalLinearStepper.js b/docs/src/pages/demos/steppers/HorizontalLinearStepper.js
index 83b2f8a3d33da2..e7bc7b7d23415d 100644
--- a/docs/src/pages/demos/steppers/HorizontalLinearStepper.js
+++ b/docs/src/pages/demos/steppers/HorizontalLinearStepper.js
@@ -43,9 +43,7 @@ class HorizontalLinearStepper extends React.Component {
     skipped: new Set(),
   };
 
-  isStepOptional = step => {
-    return step === 1;
-  };
+  isStepOptional = step => step === 1;
 
   handleNext = () => {
     const { activeStep } = this.state;
diff --git a/docs/src/pages/demos/steppers/HorizontalNonLinearAlternativeLabelStepper.js b/docs/src/pages/demos/steppers/HorizontalNonLinearAlternativeLabelStepper.js
index c1a4b687cc07da..d2cbb963e11b64 100644
--- a/docs/src/pages/demos/steppers/HorizontalNonLinearAlternativeLabelStepper.js
+++ b/docs/src/pages/demos/steppers/HorizontalNonLinearAlternativeLabelStepper.js
@@ -50,13 +50,9 @@ class HorizontalNonLinearAlternativeLabelStepper extends React.Component {
     skipped: new Set(),
   };
 
-  totalSteps = () => {
-    return getSteps().length;
-  };
+  totalSteps = () => getSteps().length;
 
-  isStepOptional = step => {
-    return step === 1;
-  };
+  isStepOptional = step => step === 1;
 
   handleSkip = () => {
     const { activeStep } = this.state;
diff --git a/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.hooks.js b/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.hooks.js
index 92c05a07bf8ce4..2c62c6f0422ae6 100644
--- a/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.hooks.js
+++ b/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.hooks.js
@@ -97,15 +97,13 @@ function HorizontalNonLinearStepper() {
   return (
     <div className={classes.root}>
       <Stepper nonLinear activeStep={activeStep}>
-        {steps.map((label, index) => {
-          return (
-            <Step key={label}>
-              <StepButton onClick={handleStep(index)} completed={completed[index]}>
-                {label}
-              </StepButton>
-            </Step>
-          );
-        })}
+        {steps.map((label, index) => (
+          <Step key={label}>
+            <StepButton onClick={handleStep(index)} completed={completed[index]}>
+              {label}
+            </StepButton>
+          </Step>
+        ))}
       </Stepper>
       <div>
         {allStepsCompleted() ? (
diff --git a/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.js b/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.js
index c770da501c6b7a..115d70ace7f2cd 100644
--- a/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.js
+++ b/docs/src/pages/demos/steppers/HorizontalNonLinearStepper.js
@@ -46,9 +46,7 @@ class HorizontalNonLinearStepper extends React.Component {
     completed: {},
   };
 
-  totalSteps = () => {
-    return getSteps().length;
-  };
+  totalSteps = () => getSteps().length;
 
   handleNext = () => {
     let activeStep;
@@ -114,18 +112,13 @@ class HorizontalNonLinearStepper extends React.Component {
     return (
       <div className={classes.root}>
         <Stepper nonLinear activeStep={activeStep}>
-          {steps.map((label, index) => {
-            return (
-              <Step key={label}>
-                <StepButton
-                  onClick={this.handleStep(index)}
-                  completed={this.state.completed[index]}
-                >
-                  {label}
-                </StepButton>
-              </Step>
-            );
-          })}
+          {steps.map((label, index) => (
+            <Step key={label}>
+              <StepButton onClick={this.handleStep(index)} completed={this.state.completed[index]}>
+                {label}
+              </StepButton>
+            </Step>
+          ))}
         </Stepper>
         <div>
           {this.allStepsCompleted() ? (
diff --git a/docs/src/pages/demos/steppers/HorizontalNonLinearStepperWithError.js b/docs/src/pages/demos/steppers/HorizontalNonLinearStepperWithError.js
index f31ff06dd82efd..34197a1aa4ddc0 100644
--- a/docs/src/pages/demos/steppers/HorizontalNonLinearStepperWithError.js
+++ b/docs/src/pages/demos/steppers/HorizontalNonLinearStepperWithError.js
@@ -43,13 +43,9 @@ class HorizontalNonLinearStepperWithError extends React.Component {
     skipped: new Set(),
   };
 
-  isStepOptional = step => {
-    return step === 1;
-  };
+  isStepOptional = step => step === 1;
 
-  isStepFailed = step => {
-    return step === 1;
-  };
+  isStepFailed = step => step === 1;
 
   handleNext = () => {
     const { activeStep } = this.state;
diff --git a/docs/src/pages/demos/steppers/VerticalLinearStepper.hooks.js b/docs/src/pages/demos/steppers/VerticalLinearStepper.hooks.js
index 0b154d06b6d1b6..b248d0b0ca10cc 100644
--- a/docs/src/pages/demos/steppers/VerticalLinearStepper.hooks.js
+++ b/docs/src/pages/demos/steppers/VerticalLinearStepper.hooks.js
@@ -66,35 +66,33 @@ function VerticalLinearStepper() {
   return (
     <div className={classes.root}>
       <Stepper activeStep={activeStep} orientation="vertical">
-        {steps.map((label, index) => {
-          return (
-            <Step key={label}>
-              <StepLabel>{label}</StepLabel>
-              <StepContent>
-                <Typography>{getStepContent(index)}</Typography>
-                <div className={classes.actionsContainer}>
-                  <div>
-                    <Button
-                      disabled={activeStep === 0}
-                      onClick={handleBack}
-                      className={classes.button}
-                    >
-                      Back
-                    </Button>
-                    <Button
-                      variant="contained"
-                      color="primary"
-                      onClick={handleNext}
-                      className={classes.button}
-                    >
-                      {activeStep === steps.length - 1 ? 'Finish' : 'Next'}
-                    </Button>
-                  </div>
+        {steps.map((label, index) => (
+          <Step key={label}>
+            <StepLabel>{label}</StepLabel>
+            <StepContent>
+              <Typography>{getStepContent(index)}</Typography>
+              <div className={classes.actionsContainer}>
+                <div>
+                  <Button
+                    disabled={activeStep === 0}
+                    onClick={handleBack}
+                    className={classes.button}
+                  >
+                    Back
+                  </Button>
+                  <Button
+                    variant="contained"
+                    color="primary"
+                    onClick={handleNext}
+                    className={classes.button}
+                  >
+                    {activeStep === steps.length - 1 ? 'Finish' : 'Next'}
+                  </Button>
                 </div>
-              </StepContent>
-            </Step>
-          );
-        })}
+              </div>
+            </StepContent>
+          </Step>
+        ))}
       </Stepper>
       {activeStep === steps.length && (
         <Paper square elevation={0} className={classes.resetContainer}>
diff --git a/docs/src/pages/demos/steppers/VerticalLinearStepper.js b/docs/src/pages/demos/steppers/VerticalLinearStepper.js
index 1a8835882c7a2c..e2866b501e1d37 100644
--- a/docs/src/pages/demos/steppers/VerticalLinearStepper.js
+++ b/docs/src/pages/demos/steppers/VerticalLinearStepper.js
@@ -78,35 +78,33 @@ class VerticalLinearStepper extends React.Component {
     return (
       <div className={classes.root}>
         <Stepper activeStep={activeStep} orientation="vertical">
-          {steps.map((label, index) => {
-            return (
-              <Step key={label}>
-                <StepLabel>{label}</StepLabel>
-                <StepContent>
-                  <Typography>{getStepContent(index)}</Typography>
-                  <div className={classes.actionsContainer}>
-                    <div>
-                      <Button
-                        disabled={activeStep === 0}
-                        onClick={this.handleBack}
-                        className={classes.button}
-                      >
-                        Back
-                      </Button>
-                      <Button
-                        variant="contained"
-                        color="primary"
-                        onClick={this.handleNext}
-                        className={classes.button}
-                      >
-                        {activeStep === steps.length - 1 ? 'Finish' : 'Next'}
-                      </Button>
-                    </div>
+          {steps.map((label, index) => (
+            <Step key={label}>
+              <StepLabel>{label}</StepLabel>
+              <StepContent>
+                <Typography>{getStepContent(index)}</Typography>
+                <div className={classes.actionsContainer}>
+                  <div>
+                    <Button
+                      disabled={activeStep === 0}
+                      onClick={this.handleBack}
+                      className={classes.button}
+                    >
+                      Back
+                    </Button>
+                    <Button
+                      variant="contained"
+                      color="primary"
+                      onClick={this.handleNext}
+                      className={classes.button}
+                    >
+                      {activeStep === steps.length - 1 ? 'Finish' : 'Next'}
+                    </Button>
                   </div>
-                </StepContent>
-              </Step>
-            );
-          })}
+                </div>
+              </StepContent>
+            </Step>
+          ))}
         </Stepper>
         {activeStep === steps.length && (
           <Paper square elevation={0} className={classes.resetContainer}>
diff --git a/docs/src/pages/demos/tables/CustomPaginationActionsTable.hooks.js b/docs/src/pages/demos/tables/CustomPaginationActionsTable.hooks.js
index 6cc57d7eb8d274..7376f4bd0f5922 100644
--- a/docs/src/pages/demos/tables/CustomPaginationActionsTable.hooks.js
+++ b/docs/src/pages/demos/tables/CustomPaginationActionsTable.hooks.js
@@ -136,17 +136,15 @@ function CustomPaginationActionsTable() {
       <div className={classes.tableWrapper}>
         <Table className={classes.table}>
           <TableBody>
-            {rows.slice(page * rowsPerPage, page * rowsPerPage + rowsPerPage).map(row => {
-              return (
-                <TableRow key={row.id}>
-                  <TableCell component="th" scope="row">
-                    {row.name}
-                  </TableCell>
-                  <TableCell numeric>{row.calories}</TableCell>
-                  <TableCell numeric>{row.fat}</TableCell>
-                </TableRow>
-              );
-            })}
+            {rows.slice(page * rowsPerPage, page * rowsPerPage + rowsPerPage).map(row => (
+              <TableRow key={row.id}>
+                <TableCell component="th" scope="row">
+                  {row.name}
+                </TableCell>
+                <TableCell numeric>{row.calories}</TableCell>
+                <TableCell numeric>{row.fat}</TableCell>
+              </TableRow>
+            ))}
             {emptyRows > 0 && (
               <TableRow style={{ height: 48 * emptyRows }}>
                 <TableCell colSpan={6} />
diff --git a/docs/src/pages/demos/tables/CustomPaginationActionsTable.js b/docs/src/pages/demos/tables/CustomPaginationActionsTable.js
index 5c2f1ef515d1d2..2dd008658c6e6d 100644
--- a/docs/src/pages/demos/tables/CustomPaginationActionsTable.js
+++ b/docs/src/pages/demos/tables/CustomPaginationActionsTable.js
@@ -151,17 +151,15 @@ class CustomPaginationActionsTable extends React.Component {
         <div className={classes.tableWrapper}>
           <Table className={classes.table}>
             <TableBody>
-              {rows.slice(page * rowsPerPage, page * rowsPerPage + rowsPerPage).map(row => {
-                return (
-                  <TableRow key={row.id}>
-                    <TableCell component="th" scope="row">
-                      {row.name}
-                    </TableCell>
-                    <TableCell align="right">{row.calories}</TableCell>
-                    <TableCell align="right">{row.fat}</TableCell>
-                  </TableRow>
-                );
-              })}
+              {rows.slice(page * rowsPerPage, page * rowsPerPage + rowsPerPage).map(row => (
+                <TableRow key={row.id}>
+                  <TableCell component="th" scope="row">
+                    {row.name}
+                  </TableCell>
+                  <TableCell align="right">{row.calories}</TableCell>
+                  <TableCell align="right">{row.fat}</TableCell>
+                </TableRow>
+              ))}
               {emptyRows > 0 && (
                 <TableRow style={{ height: 48 * emptyRows }}>
                   <TableCell colSpan={6} />
diff --git a/docs/src/pages/demos/tables/CustomizedTable.js b/docs/src/pages/demos/tables/CustomizedTable.js
index c192eb73c3e53d..84482b0f145812 100644
--- a/docs/src/pages/demos/tables/CustomizedTable.js
+++ b/docs/src/pages/demos/tables/CustomizedTable.js
@@ -64,19 +64,17 @@ function CustomizedTable(props) {
           </TableRow>
         </TableHead>
         <TableBody>
-          {rows.map(row => {
-            return (
-              <TableRow className={classes.row} key={row.id}>
-                <CustomTableCell component="th" scope="row">
-                  {row.name}
-                </CustomTableCell>
-                <CustomTableCell align="right">{row.calories}</CustomTableCell>
-                <CustomTableCell align="right">{row.fat}</CustomTableCell>
-                <CustomTableCell align="right">{row.carbs}</CustomTableCell>
-                <CustomTableCell align="right">{row.protein}</CustomTableCell>
-              </TableRow>
-            );
-          })}
+          {rows.map(row => (
+            <TableRow className={classes.row} key={row.id}>
+              <CustomTableCell component="th" scope="row">
+                {row.name}
+              </CustomTableCell>
+              <CustomTableCell align="right">{row.calories}</CustomTableCell>
+              <CustomTableCell align="right">{row.fat}</CustomTableCell>
+              <CustomTableCell align="right">{row.carbs}</CustomTableCell>
+              <CustomTableCell align="right">{row.protein}</CustomTableCell>
+            </TableRow>
+          ))}
         </TableBody>
       </Table>
     </Paper>
diff --git a/docs/src/pages/demos/tables/EnhancedTable.hooks.js b/docs/src/pages/demos/tables/EnhancedTable.hooks.js
index 2c23e1fbe06e0a..fe6ed7ccbc4297 100644
--- a/docs/src/pages/demos/tables/EnhancedTable.hooks.js
+++ b/docs/src/pages/demos/tables/EnhancedTable.hooks.js
@@ -73,8 +73,8 @@ function EnhancedTableHead(props) {
             onChange={onSelectAllClick}
           />
         </TableCell>
-        {rows.map(row => {
-          return (
+        {rows.map(
+          row => (
             <TableCell
               key={row.id}
               numeric={row.numeric}
@@ -95,8 +95,9 @@ function EnhancedTableHead(props) {
                 </TableSortLabel>
               </Tooltip>
             </TableCell>
-          );
-        }, this)}
+          ),
+          this,
+        )}
       </TableRow>
     </TableHead>
   );
diff --git a/docs/src/pages/demos/tables/EnhancedTable.js b/docs/src/pages/demos/tables/EnhancedTable.js
index 8d309cfbcdcfb8..0ed079d1b5241c 100644
--- a/docs/src/pages/demos/tables/EnhancedTable.js
+++ b/docs/src/pages/demos/tables/EnhancedTable.js
@@ -75,8 +75,8 @@ class EnhancedTableHead extends React.Component {
               onChange={onSelectAllClick}
             />
           </TableCell>
-          {rows.map(row => {
-            return (
+          {rows.map(
+            row => (
               <TableCell
                 key={row.id}
                 align={row.numeric ? 'right' : 'left'}
@@ -97,8 +97,9 @@ class EnhancedTableHead extends React.Component {
                   </TableSortLabel>
                 </Tooltip>
               </TableCell>
-            );
-          }, this)}
+            ),
+            this,
+          )}
         </TableRow>
       </TableHead>
     );
diff --git a/docs/src/pages/demos/tables/SimpleTable.js b/docs/src/pages/demos/tables/SimpleTable.js
index d1eedba33461fa..a3c0ede6806a72 100644
--- a/docs/src/pages/demos/tables/SimpleTable.js
+++ b/docs/src/pages/demos/tables/SimpleTable.js
@@ -49,19 +49,17 @@ function SimpleTable(props) {
           </TableRow>
         </TableHead>
         <TableBody>
-          {rows.map(row => {
-            return (
-              <TableRow key={row.id}>
-                <TableCell component="th" scope="row">
-                  {row.name}
-                </TableCell>
-                <TableCell align="right">{row.calories}</TableCell>
-                <TableCell align="right">{row.fat}</TableCell>
-                <TableCell align="right">{row.carbs}</TableCell>
-                <TableCell align="right">{row.protein}</TableCell>
-              </TableRow>
-            );
-          })}
+          {rows.map(row => (
+            <TableRow key={row.id}>
+              <TableCell component="th" scope="row">
+                {row.name}
+              </TableCell>
+              <TableCell align="right">{row.calories}</TableCell>
+              <TableCell align="right">{row.fat}</TableCell>
+              <TableCell align="right">{row.carbs}</TableCell>
+              <TableCell align="right">{row.protein}</TableCell>
+            </TableRow>
+          ))}
         </TableBody>
       </Table>
     </Paper>
diff --git a/docs/src/pages/demos/tables/SpanningTable.js b/docs/src/pages/demos/tables/SpanningTable.js
index 1e60bb2d28173a..cf4a72eb88a528 100644
--- a/docs/src/pages/demos/tables/SpanningTable.js
+++ b/docs/src/pages/demos/tables/SpanningTable.js
@@ -62,16 +62,14 @@ function SpanningTable(props) {
           </TableRow>
         </TableHead>
         <TableBody>
-          {rows.map(row => {
-            return (
-              <TableRow key={row.id}>
-                <TableCell>{row.desc}</TableCell>
-                <TableCell align="right">{row.qty}</TableCell>
-                <TableCell align="right">{row.unit}</TableCell>
-                <TableCell align="right">{ccyFormat(row.price)}</TableCell>
-              </TableRow>
-            );
-          })}
+          {rows.map(row => (
+            <TableRow key={row.id}>
+              <TableCell>{row.desc}</TableCell>
+              <TableCell align="right">{row.qty}</TableCell>
+              <TableCell align="right">{row.unit}</TableCell>
+              <TableCell align="right">{ccyFormat(row.price)}</TableCell>
+            </TableRow>
+          ))}
           <TableRow>
             <TableCell rowSpan={3} />
             <TableCell colSpan={2}>Subtotal</TableCell>
diff --git a/docs/src/pages/getting-started/page-layout-examples/dashboard/SimpleTable.js b/docs/src/pages/getting-started/page-layout-examples/dashboard/SimpleTable.js
index 2a510d56bde627..9338a3a45b97ef 100644
--- a/docs/src/pages/getting-started/page-layout-examples/dashboard/SimpleTable.js
+++ b/docs/src/pages/getting-started/page-layout-examples/dashboard/SimpleTable.js
@@ -48,19 +48,17 @@ function SimpleTable(props) {
           </TableRow>
         </TableHead>
         <TableBody>
-          {data.map(n => {
-            return (
-              <TableRow key={n.id}>
-                <TableCell component="th" scope="row">
-                  {n.name}
-                </TableCell>
-                <TableCell align="right">{n.calories}</TableCell>
-                <TableCell align="right">{n.fat}</TableCell>
-                <TableCell align="right">{n.carbs}</TableCell>
-                <TableCell align="right">{n.protein}</TableCell>
-              </TableRow>
-            );
-          })}
+          {data.map(n => (
+            <TableRow key={n.id}>
+              <TableCell component="th" scope="row">
+                {n.name}
+              </TableCell>
+              <TableCell align="right">{n.calories}</TableCell>
+              <TableCell align="right">{n.fat}</TableCell>
+              <TableCell align="right">{n.carbs}</TableCell>
+              <TableCell align="right">{n.protein}</TableCell>
+            </TableRow>
+          ))}
         </TableBody>
       </Table>
     </Paper>
diff --git a/docs/src/pages/premium-themes/onepirate/modules/form/validation.js b/docs/src/pages/premium-themes/onepirate/modules/form/validation.js
index 1d4b690fd41a0a..9e5700b8a85582 100644
--- a/docs/src/pages/premium-themes/onepirate/modules/form/validation.js
+++ b/docs/src/pages/premium-themes/onepirate/modules/form/validation.js
@@ -9,10 +9,11 @@ function isDirty(value) {
 }
 
 export function required(requiredFields, values) {
-  return requiredFields.reduce((fields, field) => {
-    return {
+  return requiredFields.reduce(
+    (fields, field) => ({
       ...fields,
       ...(isDirty(values[field]) ? undefined : { [field]: 'Required' }),
-    };
-  }, {});
+    }),
+    {},
+  );
 }
diff --git a/docs/src/pages/versions/StableVersions.js b/docs/src/pages/versions/StableVersions.js
index 214a8e89f74ab3..8e23974edf383d 100644
--- a/docs/src/pages/versions/StableVersions.js
+++ b/docs/src/pages/versions/StableVersions.js
@@ -77,33 +77,31 @@ class StableVersions extends React.Component {
       <Paper className={classes.root}>
         <Table>
           <TableBody>
-            {docs.map(doc => {
-              return (
-                <TableRow key={doc.version}>
-                  <TableCell padding="dense">
-                    <Typography variant="body2">
-                      {doc.version}
-                      {doc.version === `v${process.env.LIB_VERSION}` ? ' ✓' : ''}
-                    </Typography>
-                  </TableCell>
-                  <TableCell padding="dense">
-                    <Link variant="body2" color="secondary" rel="nofollow" href={doc.url}>
-                      Documentation
-                    </Link>
-                  </TableCell>
-                  <TableCell padding="dense">
-                    <Link
-                      variant="body2"
-                      color="secondary"
-                      rel="nofollow"
-                      href={`${GITHUB_RELEASE_BASE_URL}${doc.version}`}
-                    >
-                      Release notes
-                    </Link>
-                  </TableCell>
-                </TableRow>
-              );
-            })}
+            {docs.map(doc => (
+              <TableRow key={doc.version}>
+                <TableCell padding="dense">
+                  <Typography variant="body2">
+                    {doc.version}
+                    {doc.version === `v${process.env.LIB_VERSION}` ? ' ✓' : ''}
+                  </Typography>
+                </TableCell>
+                <TableCell padding="dense">
+                  <Link variant="body2" color="secondary" rel="nofollow" href={doc.url}>
+                    Documentation
+                  </Link>
+                </TableCell>
+                <TableCell padding="dense">
+                  <Link
+                    variant="body2"
+                    color="secondary"
+                    rel="nofollow"
+                    href={`${GITHUB_RELEASE_BASE_URL}${doc.version}`}
+                  >
+                    Release notes
+                  </Link>
+                </TableCell>
+              </TableRow>
+            ))}
           </TableBody>
         </Table>
       </Paper>
diff --git a/modules/waterfall/Queue.js b/modules/waterfall/Queue.js
index 23b858b7626a60..21a1cf83b9752f 100644
--- a/modules/waterfall/Queue.js
+++ b/modules/waterfall/Queue.js
@@ -35,8 +35,8 @@ class Queue {
     });
   };
 
-  wait = (options = {}) => {
-    return waitUntil(
+  wait = (options = {}) =>
+    waitUntil(
       () => {
         if (this.err) {
           this.pendingEntries = [];
@@ -53,7 +53,6 @@ class Queue {
         delay: 50,
       },
     );
-  };
 }
 
 export default Queue;
diff --git a/package.json b/package.json
index 2b60830cd5d8d6..77f02e36615e9d 100644
--- a/package.json
+++ b/package.json
@@ -100,6 +100,7 @@
     "enzyme-adapter-react-16": "^1.3.0",
     "eslint": "^5.9.0",
     "eslint-config-airbnb": "^17.0.0",
+    "eslint-config-prettier": "^3.3.0",
     "eslint-import-resolver-webpack": "^0.10.0",
     "eslint-plugin-babel": "^5.3.0",
     "eslint-plugin-import": "^2.8.0",
diff --git a/packages/material-ui-codemod/src/v0.15.0/import-path.js b/packages/material-ui-codemod/src/v0.15.0/import-path.js
index 64cfa1138cd087..433bd97b272de2 100644
--- a/packages/material-ui-codemod/src/v0.15.0/import-path.js
+++ b/packages/material-ui-codemod/src/v0.15.0/import-path.js
@@ -76,10 +76,7 @@ export default function transformer(fileInfo, api) {
 
   return j(fileInfo.source)
     .find(j.ImportDeclaration)
-    .filter(path => {
-      // Only consider Material-UI imports
-      return path.value.source.value.indexOf('material-ui/') === 0;
-    })
+    .filter(path => path.value.source.value.indexOf('material-ui/') === 0)
     .replaceWith(path => {
       const pathOld = path.value.source.value;
       const pathsBase = getPathsBase(pathOld);
diff --git a/packages/material-ui-icons/builder.js b/packages/material-ui-icons/builder.js
index 17f3433bb76779..acab4f1f6cf4fc 100755
--- a/packages/material-ui-icons/builder.js
+++ b/packages/material-ui-icons/builder.js
@@ -73,9 +73,7 @@ function getComponentName(destPath) {
   const parts = destPath
     .replace('.js', '')
     .split(splitregex)
-    .map(part => {
-      return part.charAt(0).toUpperCase() + part.substring(1);
-    });
+    .map(part => part.charAt(0).toUpperCase() + part.substring(1));
 
   return parts.join('');
 }
@@ -189,14 +187,13 @@ async function main(options) {
     ]);
 
     const queue = new Queue(
-      svgPath => {
-        return worker({
+      svgPath =>
+        worker({
           svgPath,
           options,
           renameFilter,
           template,
-        });
-      },
+        }),
       { concurrency: 8 },
     );
 
diff --git a/packages/material-ui-icons/scripts/create-typings.js b/packages/material-ui-icons/scripts/create-typings.js
index 8c97218795db03..84c88b371710a1 100644
--- a/packages/material-ui-icons/scripts/create-typings.js
+++ b/packages/material-ui-icons/scripts/create-typings.js
@@ -14,7 +14,6 @@ function normalizeFileName(file) {
 
 function createIconTyping(file) {
   const name = normalizeFileName(file);
-  /* eslint-disable-next-line quotes */
   const contents = `export { default } from '@material-ui/core/SvgIcon';`;
   return fse.writeFile(path.resolve(TARGET_DIR, `${name}.d.ts`), contents, 'utf8');
 }
diff --git a/packages/material-ui-icons/scripts/download.js b/packages/material-ui-icons/scripts/download.js
index 703b6117c58667..70231e8892d19c 100644
--- a/packages/material-ui-icons/scripts/download.js
+++ b/packages/material-ui-icons/scripts/download.js
@@ -53,9 +53,7 @@ async function run() {
     await fse.ensureDir(path.join(__dirname, '../material-io-tools-icons'));
     const response = await fetch('https://material.io/tools/icons/static/data.json');
     const data = await response.json();
-    let icons = data.categories.reduce((acc, item) => {
-      return acc.concat(item.icons);
-    }, []);
+    let icons = data.categories.reduce((acc, item) => acc.concat(item.icons), []);
     icons = icons.map((icon, index) => ({ index, ...icon }));
     icons = icons.splice(argv.startAfter || 0);
     console.log(`${icons.length} icons to download`);
diff --git a/packages/material-ui-lab/src/SpeedDial/SpeedDial.test.js b/packages/material-ui-lab/src/SpeedDial/SpeedDial.test.js
index 734fba00c09d8a..270cc0afee1dc5 100644
--- a/packages/material-ui-lab/src/SpeedDial/SpeedDial.test.js
+++ b/packages/material-ui-lab/src/SpeedDial/SpeedDial.test.js
@@ -217,20 +217,18 @@ describe('<SpeedDial />', () => {
           icon={icon}
           onKeyDown={onkeydown}
         >
-          {Array.from({ length: actionCount }, (_, i) => {
-            return (
-              <SpeedDialAction
-                key={i}
-                ButtonProps={{
-                  buttonRef: ref => {
-                    actionRefs[i] = ref;
-                  },
-                }}
-                icon={icon}
-                tooltipTitle={`action${i}`}
-              />
-            );
-          })}
+          {Array.from({ length: actionCount }, (_, i) => (
+            <SpeedDialAction
+              key={i}
+              ButtonProps={{
+                buttonRef: ref => {
+                  actionRefs[i] = ref;
+                },
+              }}
+              icon={icon}
+              tooltipTitle={`action${i}`}
+            />
+          ))}
         </SpeedDial>,
       );
     };
diff --git a/packages/material-ui-styles/src/makeStyles.js b/packages/material-ui-styles/src/makeStyles.js
index 38123d81420ddf..593fe2587461e3 100644
--- a/packages/material-ui-styles/src/makeStyles.js
+++ b/packages/material-ui-styles/src/makeStyles.js
@@ -74,16 +74,15 @@ function makeStyles(stylesOrCreator, options = {}) {
 
     // Execute asynchronously every time the theme changes.
     React.useEffect(
-      () => {
-        return function cleanup() {
+      () =>
+        function cleanup() {
           detach({
             state,
             stylesCreator,
             stylesOptions,
             theme,
           });
-        };
-      },
+        },
       [theme],
     );
 
diff --git a/packages/material-ui-utils/src/componentPropType.test.js b/packages/material-ui-utils/src/componentPropType.test.js
index 48edd2fe500412..d2581fa22c8fb7 100644
--- a/packages/material-ui-utils/src/componentPropType.test.js
+++ b/packages/material-ui-utils/src/componentPropType.test.js
@@ -37,7 +37,7 @@ describe('componentPropType', () => {
     consoleErrorMock.reset();
   });
 
-  it('describe .isRequired', () => {
+  describe('describe .isRequired', () => {
     it('rejects null', () => {
       testPropType(
         undefined,
diff --git a/packages/material-ui-utils/src/getDisplayName.test.js b/packages/material-ui-utils/src/getDisplayName.test.js
index a2070c57743572..abbc20f7bed82a 100644
--- a/packages/material-ui-utils/src/getDisplayName.test.js
+++ b/packages/material-ui-utils/src/getDisplayName.test.js
@@ -25,9 +25,7 @@ describe('utils/getDisplayName.js', () => {
         return <div />;
       }
 
-      const AndAnotherComponent = () => {
-        return <div />;
-      };
+      const AndAnotherComponent = () => <div />;
 
       assert.strictEqual(getDisplayName(SomeComponent), 'SomeComponent');
       assert.strictEqual(getDisplayName(SomeOtherComponent), 'CustomDisplayName');
@@ -45,9 +43,7 @@ describe('utils/getDisplayName.js', () => {
         return <div />;
       }
 
-      const SomeOtherFunction = () => {
-        return <div />;
-      };
+      const SomeOtherFunction = () => <div />;
 
       assert.strictEqual(getFunctionName(SomeFunction), 'SomeFunction');
       assert.strictEqual(getFunctionName(SomeOtherFunction), 'SomeOtherFunction');
diff --git a/packages/material-ui/src/BottomNavigation/BottomNavigation.test.js b/packages/material-ui/src/BottomNavigation/BottomNavigation.test.js
index f8a114ea6c5c5f..53a7b06c1ba974 100755
--- a/packages/material-ui/src/BottomNavigation/BottomNavigation.test.js
+++ b/packages/material-ui/src/BottomNavigation/BottomNavigation.test.js
@@ -79,7 +79,7 @@ describe('<BottomNavigation />', () => {
     assert.strictEqual(wrapper.childAt(1).props().showLabel, false);
   });
 
-  it('should pass selected prop to children', () => {
+  it('should forward the click', () => {
     const handleChange = spy();
     const wrapper = mount(
       <BottomNavigation showLabels value={0} onChange={handleChange}>
diff --git a/packages/material-ui/src/ButtonBase/ButtonBase.test.js b/packages/material-ui/src/ButtonBase/ButtonBase.test.js
index 6be5cde167a70c..e64d3b7e02fd4c 100644
--- a/packages/material-ui/src/ButtonBase/ButtonBase.test.js
+++ b/packages/material-ui/src/ButtonBase/ButtonBase.test.js
@@ -153,7 +153,7 @@ describe('<ButtonBase />', () => {
       );
     });
 
-    it('should start the ripple when the mouse is pressed', () => {
+    it('should start the ripple when the mouse is pressed 1', () => {
       wrapper.instance().ripple = { start: spy() };
       wrapper.simulate('mouseDown', {});
 
@@ -167,7 +167,7 @@ describe('<ButtonBase />', () => {
       assert.strictEqual(wrapper.instance().ripple.stop.callCount, 1);
     });
 
-    it('should start the ripple when the mouse is pressed', () => {
+    it('should start the ripple when the mouse is pressed 2', () => {
       wrapper.instance().ripple = { start: spy() };
       wrapper.simulate('mouseDown', {});
 
@@ -181,7 +181,7 @@ describe('<ButtonBase />', () => {
       assert.strictEqual(wrapper.instance().ripple.stop.callCount, 1);
     });
 
-    it('should start the ripple when the mouse is pressed', () => {
+    it('should start the ripple when the mouse is pressed 3', () => {
       wrapper.instance().ripple = { start: spy() };
       wrapper.simulate('mouseDown', {});
 
diff --git a/packages/material-ui/src/ButtonBase/Ripple.test.js b/packages/material-ui/src/ButtonBase/Ripple.test.js
index 4c00b0f38369e0..9a74aef2bc6bbf 100644
--- a/packages/material-ui/src/ButtonBase/Ripple.test.js
+++ b/packages/material-ui/src/ButtonBase/Ripple.test.js
@@ -70,7 +70,7 @@ describe('<Ripple />', () => {
     });
   });
 
-  describe('pulsating and stopping', () => {
+  describe('pulsating and stopping 1', () => {
     let wrapper;
 
     before(() => {
@@ -116,7 +116,7 @@ describe('<Ripple />', () => {
     });
   });
 
-  describe('pulsating and stopping', () => {
+  describe('pulsating and stopping 2', () => {
     let wrapper;
     let clock;
     let callbackSpy;
diff --git a/packages/material-ui/src/ButtonBase/TouchRipple.js b/packages/material-ui/src/ButtonBase/TouchRipple.js
index 96e9fd55f62171..95f809c567d449 100644
--- a/packages/material-ui/src/ButtonBase/TouchRipple.js
+++ b/packages/material-ui/src/ButtonBase/TouchRipple.js
@@ -209,8 +209,8 @@ class TouchRipple extends React.PureComponent {
   startCommit = params => {
     const { pulsate, rippleX, rippleY, rippleSize, cb } = params;
 
-    this.setState(state => {
-      return {
+    this.setState(
+      state => ({
         nextKey: state.nextKey + 1,
         ripples: [
           ...state.ripples,
@@ -227,8 +227,9 @@ class TouchRipple extends React.PureComponent {
             rippleSize={rippleSize}
           />,
         ],
-      };
-    }, cb);
+      }),
+      cb,
+    );
   };
 
   stop = (event, cb) => {
diff --git a/packages/material-ui/src/Collapse/Collapse.js b/packages/material-ui/src/Collapse/Collapse.js
index 0d58cff5eb8501..816898b83fe4cb 100644
--- a/packages/material-ui/src/Collapse/Collapse.js
+++ b/packages/material-ui/src/Collapse/Collapse.js
@@ -150,33 +150,31 @@ class Collapse extends React.Component {
         timeout={timeout === 'auto' ? null : timeout}
         {...other}
       >
-        {(state, childProps) => {
-          return (
-            <Component
-              className={classNames(
-                classes.container,
-                {
-                  [classes.entered]: state === 'entered',
-                },
-                className,
-              )}
-              style={{
-                ...style,
-                minHeight: collapsedHeight,
+        {(state, childProps) => (
+          <Component
+            className={classNames(
+              classes.container,
+              {
+                [classes.entered]: state === 'entered',
+              },
+              className,
+            )}
+            style={{
+              ...style,
+              minHeight: collapsedHeight,
+            }}
+            {...childProps}
+          >
+            <div
+              className={classes.wrapper}
+              ref={ref => {
+                this.wrapperRef = ref;
               }}
-              {...childProps}
             >
-              <div
-                className={classes.wrapper}
-                ref={ref => {
-                  this.wrapperRef = ref;
-                }}
-              >
-                <div className={classes.wrapperInner}>{children}</div>
-              </div>
-            </Component>
-          );
-        }}
+              <div className={classes.wrapperInner}>{children}</div>
+            </div>
+          </Component>
+        )}
       </Transition>
     );
   }
diff --git a/packages/material-ui/src/Fade/Fade.js b/packages/material-ui/src/Fade/Fade.js
index e6793eeb30bdad..bec8fd6c6769d3 100644
--- a/packages/material-ui/src/Fade/Fade.js
+++ b/packages/material-ui/src/Fade/Fade.js
@@ -59,16 +59,16 @@ class Fade extends React.Component {
 
     return (
       <Transition appear onEnter={this.handleEnter} onExit={this.handleExit} {...other}>
-        {(state, childProps) => {
-          return React.cloneElement(children, {
+        {(state, childProps) =>
+          React.cloneElement(children, {
             style: {
               opacity: 0,
               ...styles[state],
               ...style,
             },
             ...childProps,
-          });
-        }}
+          })
+        }
       </Transition>
     );
   }
diff --git a/packages/material-ui/src/Fade/Fade.test.js b/packages/material-ui/src/Fade/Fade.test.js
index 839f3f1b56e059..ca616e394f3a60 100644
--- a/packages/material-ui/src/Fade/Fade.test.js
+++ b/packages/material-ui/src/Fade/Fade.test.js
@@ -79,7 +79,7 @@ describe('<Fade />', () => {
   });
 
   describe('prop: appear', () => {
-    it('should work when initially hidden', () => {
+    it('should work when initially hidden, appear=true', () => {
       const wrapper = mount(
         <Fade in={false} appear>
           <div>Foo</div>
@@ -90,7 +90,7 @@ describe('<Fade />', () => {
       });
     });
 
-    it('should work when initially hidden', () => {
+    it('should work when initially hidden, appear=false', () => {
       const wrapper = mount(
         <Fade in={false} appear={false}>
           <div>Foo</div>
diff --git a/packages/material-ui/src/FormControl/FormControl.test.js b/packages/material-ui/src/FormControl/FormControl.test.js
index 02b17311ce99e9..56e60ce8ea30d4 100644
--- a/packages/material-ui/src/FormControl/FormControl.test.js
+++ b/packages/material-ui/src/FormControl/FormControl.test.js
@@ -57,20 +57,14 @@ describe('<FormControl />', () => {
       assert.strictEqual(findOutermostIntrinsic(wrapper).hasClass(classes.marginDense), true);
       assert.strictEqual(findOutermostIntrinsic(wrapper).hasClass(classes.marginNormal), false);
     });
-  });
-
-  describe('initial state', () => {
-    let wrapper;
-
-    beforeEach(() => {
-      wrapper = mount(<FormControl />);
-    });
 
     it('should not be filled initially', () => {
+      const wrapper = mount(<FormControl />);
       assert.strictEqual(getState(wrapper).filled, false);
     });
 
     it('should not be focused initially', () => {
+      const wrapper = mount(<FormControl />);
       assert.strictEqual(getState(wrapper).focused, false);
     });
   });
diff --git a/packages/material-ui/src/FormControl/withFormControlContext.js b/packages/material-ui/src/FormControl/withFormControlContext.js
index 9da0532ceafbe8..c1b9f6c007dc3b 100644
--- a/packages/material-ui/src/FormControl/withFormControlContext.js
+++ b/packages/material-ui/src/FormControl/withFormControlContext.js
@@ -4,15 +4,11 @@ import FormControlContext from './FormControlContext';
 import { getDisplayName } from '@material-ui/utils';
 
 export default function withFormControlContext(Component) {
-  const EnhancedComponent = props => {
-    return (
-      <FormControlContext.Consumer>
-        {context => {
-          return <Component muiFormControl={context} {...props} />;
-        }}
-      </FormControlContext.Consumer>
-    );
-  };
+  const EnhancedComponent = props => (
+    <FormControlContext.Consumer>
+      {context => <Component muiFormControl={context} {...props} />}
+    </FormControlContext.Consumer>
+  );
 
   if (process.env.NODE_ENV !== 'production') {
     EnhancedComponent.displayName = `WithFormControlContext(${getDisplayName(Component)})`;
diff --git a/packages/material-ui/src/GridList/GridList.test.js b/packages/material-ui/src/GridList/GridList.test.js
index 034d0e9016ce75..21f3dbbaa4a4d6 100644
--- a/packages/material-ui/src/GridList/GridList.test.js
+++ b/packages/material-ui/src/GridList/GridList.test.js
@@ -32,13 +32,13 @@ describe('<GridList />', () => {
     assert.strictEqual(wrapper.name(), 'ul');
   });
 
-  it('should render a ul', () => {
+  it('should accept a component property', () => {
     const wrapper = shallow(
-      <GridList component="ul">
+      <GridList component="li">
         <br />
       </GridList>,
     );
-    assert.strictEqual(wrapper.name(), 'ul');
+    assert.strictEqual(wrapper.name(), 'li');
   });
 
   it('should render children and change cellHeight', () => {
diff --git a/packages/material-ui/src/Grow/Grow.js b/packages/material-ui/src/Grow/Grow.js
index 17f5b30725b87b..1a83e254d22007 100644
--- a/packages/material-ui/src/Grow/Grow.js
+++ b/packages/material-ui/src/Grow/Grow.js
@@ -119,8 +119,8 @@ class Grow extends React.Component {
         timeout={timeout === 'auto' ? null : timeout}
         {...other}
       >
-        {(state, childProps) => {
-          return React.cloneElement(children, {
+        {(state, childProps) =>
+          React.cloneElement(children, {
             style: {
               opacity: 0,
               transform: getScale(0.75),
@@ -128,8 +128,8 @@ class Grow extends React.Component {
               ...style,
             },
             ...childProps,
-          });
-        }}
+          })
+        }
       </Transition>
     );
   }
diff --git a/packages/material-ui/src/InputBase/Textarea.test.js b/packages/material-ui/src/InputBase/Textarea.test.js
index 71357d4a6ad18e..b90ff947edf4f2 100644
--- a/packages/material-ui/src/InputBase/Textarea.test.js
+++ b/packages/material-ui/src/InputBase/Textarea.test.js
@@ -113,6 +113,12 @@ describe('<Textarea />', () => {
       mount(<Textarea textareaRef={handleRef} />);
       assert.strictEqual(handleRef.callCount, 1);
     });
+
+    it('should be able to return the input node via a ref object', () => {
+      const ref = React.createRef();
+      mount(<Textarea textareaRef={ref} />);
+      assert.strictEqual(ref.current.tagName, 'TEXTAREA');
+    });
   });
 
   describe('prop: onChange', () => {
@@ -155,12 +161,4 @@ describe('<Textarea />', () => {
       assert.strictEqual(wrapper.state().height, 43);
     });
   });
-
-  describe('prop: textareaRef', () => {
-    it('should be able to return the input node via a ref object', () => {
-      const ref = React.createRef();
-      mount(<Textarea textareaRef={ref} />);
-      assert.strictEqual(ref.current.tagName, 'TEXTAREA');
-    });
-  });
 });
diff --git a/packages/material-ui/src/ListItem/ListItem.test.js b/packages/material-ui/src/ListItem/ListItem.test.js
index 0cd1fe2d5dddcf..a0170954c38981 100644
--- a/packages/material-ui/src/ListItem/ListItem.test.js
+++ b/packages/material-ui/src/ListItem/ListItem.test.js
@@ -77,12 +77,12 @@ describe('<ListItem />', () => {
   });
 
   describe('prop: component', () => {
-    it('should change the component', () => {
+    it('should change the component to a', () => {
       const wrapper = mount(<ListItem button component="a" />);
       assert.strictEqual(wrapper.getDOMNode().nodeName, 'A');
     });
 
-    it('should change the component', () => {
+    it('should change the component to li', () => {
       const wrapper = mount(<ListItem button component="li" />);
       assert.strictEqual(wrapper.getDOMNode().nodeName, 'LI');
     });
diff --git a/packages/material-ui/src/ListItemAvatar/ListItemAvatar.js b/packages/material-ui/src/ListItemAvatar/ListItemAvatar.js
index d3bcd0fbac005b..8784ca6501263e 100644
--- a/packages/material-ui/src/ListItemAvatar/ListItemAvatar.js
+++ b/packages/material-ui/src/ListItemAvatar/ListItemAvatar.js
@@ -33,8 +33,8 @@ function ListItemAvatar(props) {
 
   return (
     <ListContext.Consumer>
-      {context => {
-        return React.cloneElement(children, {
+      {context =>
+        React.cloneElement(children, {
           className: classNames(
             {
               [classes.root]: context.dense,
@@ -48,8 +48,8 @@ function ListItemAvatar(props) {
             children.props.childrenClassName,
           ),
           ...other,
-        });
-      }}
+        })
+      }
     </ListContext.Consumer>
   );
 }
diff --git a/packages/material-ui/src/Modal/Modal.test.js b/packages/material-ui/src/Modal/Modal.test.js
index 580b8415a88541..1c62afb03cddf9 100644
--- a/packages/material-ui/src/Modal/Modal.test.js
+++ b/packages/material-ui/src/Modal/Modal.test.js
@@ -190,7 +190,7 @@ describe('<Modal />', () => {
     });
   });
 
-  describe('backdrop', () => {
+  describe('backdrop 2', () => {
     it('should render a backdrop component into the portal before the modal content', () => {
       mount(
         <Modal open id="modal">
diff --git a/packages/material-ui/src/Modal/ModalManager.test.js b/packages/material-ui/src/Modal/ModalManager.test.js
index e58bedbd7436ae..d763bf577b01fe 100644
--- a/packages/material-ui/src/Modal/ModalManager.test.js
+++ b/packages/material-ui/src/Modal/ModalManager.test.js
@@ -60,7 +60,7 @@ describe('ModalManager', () => {
       assert.strictEqual(idx, 1, 'should be the second modal');
     });
 
-    it('should add modal2', () => {
+    it('should add modal2 2', () => {
       const idx = modalManager.add(modal2, container1);
       modalManager.mount(modal2);
       assert.strictEqual(idx, 2, 'should be the "third" modal');
@@ -77,7 +77,7 @@ describe('ModalManager', () => {
       assert.strictEqual(idx, 1);
     });
 
-    it('should remove modal2', () => {
+    it('should remove modal2 2', () => {
       const idx = modalManager.remove(modal2);
       assert.strictEqual(idx, 1);
       assert.strictEqual(modalManager.isTopModal(modal1), true);
diff --git a/packages/material-ui/src/Popover/Popover.js b/packages/material-ui/src/Popover/Popover.js
index 3d2e7f749ecd7a..41b96473d8c92c 100644
--- a/packages/material-ui/src/Popover/Popover.js
+++ b/packages/material-ui/src/Popover/Popover.js
@@ -45,9 +45,7 @@ function getOffsetLeft(rect, horizontal) {
 
 function getTransformOriginValue(transformOrigin) {
   return [transformOrigin.horizontal, transformOrigin.vertical]
-    .map(n => {
-      return typeof n === 'number' ? `${n}px` : n;
-    })
+    .map(n => (typeof n === 'number' ? `${n}px` : n))
     .join(' ');
 }
 
diff --git a/packages/material-ui/src/Popover/Popover.test.js b/packages/material-ui/src/Popover/Popover.test.js
index 42a7c38f5a5ee7..8255ecb4d9ca4f 100644
--- a/packages/material-ui/src/Popover/Popover.test.js
+++ b/packages/material-ui/src/Popover/Popover.test.js
@@ -368,61 +368,55 @@ describe('<Popover />', () => {
       window.document.body.removeChild(anchorEl);
     });
 
-    it('should be positioned over the top left of the anchor', () => {
-      return openPopover({ vertical: 'top', horizontal: 'left' }).then(() => {
-        const anchorRect = anchorEl.getBoundingClientRect();
-        const expectedTop = anchorRect.top <= 16 ? 16 : anchorRect.top;
-        const expectedLeft = anchorRect.left <= 16 ? 16 : anchorRect.left;
-        expectPopover(expectedTop, expectedLeft);
-      });
+    it('should be positioned over the top left of the anchor', async () => {
+      await openPopover({ vertical: 'top', horizontal: 'left' });
+      const anchorRect = anchorEl.getBoundingClientRect();
+      const expectedTop = anchorRect.top <= 16 ? 16 : anchorRect.top;
+      const expectedLeft = anchorRect.left <= 16 ? 16 : anchorRect.left;
+      expectPopover(expectedTop, expectedLeft);
     });
 
-    it('should be positioned over the center left of the anchor', () => {
-      return openPopover({ vertical: 'center', horizontal: 'left' }).then(() => {
-        const anchorRect = anchorEl.getBoundingClientRect();
-        const anchorTop = anchorRect.top + anchorRect.height / 2;
-        const expectedTop = anchorTop <= 16 ? 16 : anchorTop;
-        const expectedLeft = anchorRect.left <= 16 ? 16 : anchorRect.left;
-        expectPopover(expectedTop, expectedLeft);
-      });
+    it('should be positioned over the center left of the anchor', async () => {
+      await openPopover({ vertical: 'center', horizontal: 'left' });
+      const anchorRect = anchorEl.getBoundingClientRect();
+      const anchorTop = anchorRect.top + anchorRect.height / 2;
+      const expectedTop = anchorTop <= 16 ? 16 : anchorTop;
+      const expectedLeft = anchorRect.left <= 16 ? 16 : anchorRect.left;
+      expectPopover(expectedTop, expectedLeft);
     });
 
-    it('should be positioned over the bottom left of the anchor', () => {
-      return openPopover({ vertical: 'bottom', horizontal: 'left' }).then(() => {
-        const anchorRect = anchorEl.getBoundingClientRect();
-        const expectedTop = anchorRect.bottom <= 16 ? 16 : anchorRect.bottom;
-        const expectedLeft = anchorRect.left <= 16 ? 16 : anchorRect.left;
-        expectPopover(expectedTop, expectedLeft);
-      });
+    it('should be positioned over the bottom left of the anchor', async () => {
+      await openPopover({ vertical: 'bottom', horizontal: 'left' });
+      const anchorRect = anchorEl.getBoundingClientRect();
+      const expectedTop = anchorRect.bottom <= 16 ? 16 : anchorRect.bottom;
+      const expectedLeft = anchorRect.left <= 16 ? 16 : anchorRect.left;
+      expectPopover(expectedTop, expectedLeft);
     });
 
-    it('should be positioned over the center center of the anchor', () => {
-      return openPopover({ vertical: 'center', horizontal: 'center' }).then(() => {
-        const anchorRect = anchorEl.getBoundingClientRect();
-        const anchorTop = anchorRect.top + anchorRect.height / 2;
-        const anchorLeft = anchorRect.left + anchorRect.height / 2;
-        const expectedTop = anchorTop <= 16 ? 16 : anchorTop;
-        const expectedLeft = anchorLeft <= 16 ? 16 : anchorLeft;
-        expectPopover(expectedTop, expectedLeft);
-      });
+    it('should be positioned over the center center of the anchor', async () => {
+      await openPopover({ vertical: 'center', horizontal: 'center' });
+      const anchorRect = anchorEl.getBoundingClientRect();
+      const anchorTop = anchorRect.top + anchorRect.height / 2;
+      const anchorLeft = anchorRect.left + anchorRect.height / 2;
+      const expectedTop = anchorTop <= 16 ? 16 : anchorTop;
+      const expectedLeft = anchorLeft <= 16 ? 16 : anchorLeft;
+      expectPopover(expectedTop, expectedLeft);
     });
 
-    it('should be positioned over the top right of the anchor', () => {
-      return openPopover({ vertical: 'top', horizontal: 'right' }).then(() => {
-        const anchorRect = anchorEl.getBoundingClientRect();
-        const expectedTop = anchorRect.top <= 16 ? 16 : anchorRect.top;
-        const expectedLeft = anchorRect.right <= 16 ? 16 : anchorRect.right;
-        expectPopover(expectedTop, expectedLeft);
-      });
+    it('should be positioned over the top right of the anchor', async () => {
+      await openPopover({ vertical: 'top', horizontal: 'right' });
+      const anchorRect = anchorEl.getBoundingClientRect();
+      const expectedTop = anchorRect.top <= 16 ? 16 : anchorRect.top;
+      const expectedLeft = anchorRect.right <= 16 ? 16 : anchorRect.right;
+      expectPopover(expectedTop, expectedLeft);
     });
 
-    it('should be positioned over the bottom right of the anchor', () => {
-      return openPopover({ vertical: 'bottom', horizontal: 'right' }).then(() => {
-        const anchorRect = anchorEl.getBoundingClientRect();
-        const expectedTop = anchorRect.bottom <= 16 ? 16 : anchorRect.bottom;
-        const expectedLeft = anchorRect.right <= 16 ? 16 : anchorRect.right;
-        expectPopover(expectedTop, expectedLeft);
-      });
+    it('should be positioned over the bottom right of the anchor', async () => {
+      await openPopover({ vertical: 'bottom', horizontal: 'right' });
+      const anchorRect = anchorEl.getBoundingClientRect();
+      const expectedTop = anchorRect.bottom <= 16 ? 16 : anchorRect.bottom;
+      const expectedLeft = anchorRect.right <= 16 ? 16 : anchorRect.right;
+      expectPopover(expectedTop, expectedLeft);
     });
 
     it('should pass through container prop if container and anchorEl props are provided', () => {
@@ -438,8 +432,8 @@ describe('<Popover />', () => {
       );
     });
 
-    it("should use anchorEl's parent body as container if container prop not provided", () => {
-      return openPopover(undefined, true).then(() => {
+    it("should use anchorEl's parent body as container if container not provided", async () => {
+      openPopover(undefined, true).then(() => {
         assert.strictEqual(
           wrapper
             .dive()
@@ -473,8 +467,8 @@ describe('<Popover />', () => {
     let expectPopover;
 
     before(() => {
-      openPopover = anchorOrigin => {
-        return new Promise(resolve => {
+      openPopover = anchorOrigin =>
+        new Promise(resolve => {
           wrapper = mount(
             <Popover
               {...defaultProps}
@@ -492,7 +486,6 @@ describe('<Popover />', () => {
           );
           wrapper.setProps({ open: true });
         });
-      };
 
       expectPopover = (top, left) => {
         assert.strictEqual(
@@ -510,16 +503,15 @@ describe('<Popover />', () => {
       };
     });
 
-    it('should be positioned according to the passed coordinates', () => {
-      return openPopover().then(() => {
+    it('should be positioned according to the passed coordinates', async () => {
+      openPopover().then(() => {
         expectPopover(anchorPosition.top, anchorPosition.left);
       });
     });
 
-    it('should ignore the anchorOrigin prop when being positioned', () => {
-      return openPopover({ vertical: 'top', horizontal: 'right' }).then(() => {
-        expectPopover(anchorPosition.top, anchorPosition.left);
-      });
+    it('should ignore the anchorOrigin prop when being positioned', async () => {
+      await openPopover({ vertical: 'top', horizontal: 'right' });
+      expectPopover(anchorPosition.top, anchorPosition.left);
     });
   });
 
@@ -530,8 +522,8 @@ describe('<Popover />', () => {
     let expectPopover;
 
     before(() => {
-      openPopover = () => {
-        return new Promise(resolve => {
+      openPopover = () =>
+        new Promise(resolve => {
           wrapper = mount(
             <Popover
               {...defaultProps}
@@ -553,7 +545,6 @@ describe('<Popover />', () => {
           );
           wrapper.setProps({ open: true });
         });
-      };
 
       expectPopover = (top, left) => {
         assert.strictEqual(
@@ -571,8 +562,8 @@ describe('<Popover />', () => {
       };
     });
 
-    it('should not try to change the position', () => {
-      return openPopover().then(() => {
+    it('should not try to change the position', async () => {
+      openPopover().then(() => {
         expectPopover(11, 12);
       });
     });
diff --git a/packages/material-ui/src/Portal/Portal.js b/packages/material-ui/src/Portal/Portal.js
index fe1bf1e72041f8..39e45a05f6c704 100644
--- a/packages/material-ui/src/Portal/Portal.js
+++ b/packages/material-ui/src/Portal/Portal.js
@@ -57,9 +57,7 @@ class Portal extends React.Component {
   /**
    * @public
    */
-  getMountNode = () => {
-    return this.mountNode;
-  };
+  getMountNode = () => this.mountNode;
 
   render() {
     const { children, disablePortal } = this.props;
diff --git a/packages/material-ui/src/Zoom/Zoom.js b/packages/material-ui/src/Zoom/Zoom.js
index d64714079cf30c..56fbeb9803f143 100644
--- a/packages/material-ui/src/Zoom/Zoom.js
+++ b/packages/material-ui/src/Zoom/Zoom.js
@@ -60,16 +60,16 @@ class Zoom extends React.Component {
 
     return (
       <Transition appear onEnter={this.handleEnter} onExit={this.handleExit} {...other}>
-        {(state, childProps) => {
-          return React.cloneElement(children, {
+        {(state, childProps) =>
+          React.cloneElement(children, {
             style: {
               transform: 'scale(0)',
               ...styles[state],
               ...style,
             },
             ...childProps,
-          });
-        }}
+          })
+        }
       </Transition>
     );
   }
diff --git a/packages/material-ui/src/Zoom/Zoom.test.js b/packages/material-ui/src/Zoom/Zoom.test.js
index 9bdee380fbdfef..592a9f0f47f381 100644
--- a/packages/material-ui/src/Zoom/Zoom.test.js
+++ b/packages/material-ui/src/Zoom/Zoom.test.js
@@ -79,7 +79,7 @@ describe('<Zoom />', () => {
   });
 
   describe('prop: appear', () => {
-    it('should work when initially hidden', () => {
+    it('should work when initially hidden: appear=true', () => {
       const wrapper = mount(
         <Zoom in={false} appear>
           <div>Foo</div>
@@ -90,7 +90,7 @@ describe('<Zoom />', () => {
       });
     });
 
-    it('should work when initially hidden', () => {
+    it('should work when initially hidden: appear=false', () => {
       const wrapper = mount(
         <Zoom in={false} appear={false}>
           <div>Foo</div>
diff --git a/packages/material-ui/src/styles/colorManipulator.test.js b/packages/material-ui/src/styles/colorManipulator.test.js
index cd5d644af1bf14..90ba8cbf0c9d6e 100644
--- a/packages/material-ui/src/styles/colorManipulator.test.js
+++ b/packages/material-ui/src/styles/colorManipulator.test.js
@@ -133,7 +133,7 @@ describe('utils/colorManipulator', () => {
   });
 
   describe('getLuminance', () => {
-    it('returns a valid luminance for rgb white', () => {
+    it('returns a valid luminance for rgb black', () => {
       assert.strictEqual(getLuminance('rgba(0, 0, 0)'), 0);
       assert.strictEqual(getLuminance('rgb(0, 0, 0)'), 0);
     });
diff --git a/packages/material-ui/src/styles/createMixins.js b/packages/material-ui/src/styles/createMixins.js
index ceb92da72894c7..9e937f546796cb 100644
--- a/packages/material-ui/src/styles/createMixins.js
+++ b/packages/material-ui/src/styles/createMixins.js
@@ -1,17 +1,15 @@
 export default function createMixins(breakpoints, spacing, mixins) {
   return {
-    gutters: (styles = {}) => {
-      return {
-        paddingLeft: spacing.unit * 2,
-        paddingRight: spacing.unit * 2,
-        ...styles,
-        [breakpoints.up('sm')]: {
-          paddingLeft: spacing.unit * 3,
-          paddingRight: spacing.unit * 3,
-          ...styles[breakpoints.up('sm')],
-        },
-      };
-    },
+    gutters: (styles = {}) => ({
+      paddingLeft: spacing.unit * 2,
+      paddingRight: spacing.unit * 2,
+      ...styles,
+      [breakpoints.up('sm')]: {
+        paddingLeft: spacing.unit * 3,
+        paddingRight: spacing.unit * 3,
+        ...styles[breakpoints.up('sm')],
+      },
+    }),
     toolbar: {
       minHeight: 56,
       [`${breakpoints.up('xs')} and (orientation: landscape)`]: {
diff --git a/packages/material-ui/src/test-utils/findOutermostIntrinsic.js b/packages/material-ui/src/test-utils/findOutermostIntrinsic.js
index 4c16899294fb83..343b4f82eb8416 100644
--- a/packages/material-ui/src/test-utils/findOutermostIntrinsic.js
+++ b/packages/material-ui/src/test-utils/findOutermostIntrinsic.js
@@ -5,9 +5,5 @@
  * @returns {import('enzyme').ReactWrapper} the wrapper for the outermost DOM node
  */
 export default function findOutermostIntrinsic(reactWrapper) {
-  return reactWrapper
-    .findWhere(n => {
-      return n.exists() && typeof n.type() === 'string';
-    })
-    .first();
+  return reactWrapper.findWhere(n => n.exists() && typeof n.type() === 'string').first();
 }
diff --git a/packages/material-ui/src/utils/helpers.js b/packages/material-ui/src/utils/helpers.js
index 6efb8966ea1a09..65ca07fed7d061 100644
--- a/packages/material-ui/src/utils/helpers.js
+++ b/packages/material-ui/src/utils/helpers.js
@@ -13,9 +13,7 @@ export function capitalize(string) {
 }
 
 export function contains(obj, pred) {
-  return Object.keys(pred).every(key => {
-    return obj.hasOwnProperty(key) && obj[key] === pred[key];
-  });
+  return Object.keys(pred).every(key => obj.hasOwnProperty(key) && obj[key] === pred[key]);
 }
 
 export function findIndex(arr, pred) {
diff --git a/packages/material-ui/src/utils/reactHelpers.js b/packages/material-ui/src/utils/reactHelpers.js
index bfdf759b9cc96e..1cb6595b1aded1 100644
--- a/packages/material-ui/src/utils/reactHelpers.js
+++ b/packages/material-ui/src/utils/reactHelpers.js
@@ -8,9 +8,10 @@ export function cloneElementWithClassName(child, className) {
 }
 
 export function cloneChildrenWithClassName(children, className) {
-  return React.Children.map(children, child => {
-    return React.isValidElement(child) && cloneElementWithClassName(child, className);
-  });
+  return React.Children.map(
+    children,
+    child => React.isValidElement(child) && cloneElementWithClassName(child, className),
+  );
 }
 
 export function isMuiElement(element, muiNames) {
diff --git a/packages/material-ui/test/integration/MenuList.test.js b/packages/material-ui/test/integration/MenuList.test.js
index ab053dab81e7f1..2f43951f9331d1 100644
--- a/packages/material-ui/test/integration/MenuList.test.js
+++ b/packages/material-ui/test/integration/MenuList.test.js
@@ -63,7 +63,7 @@ describe('<MenuList> integration', () => {
       assertMenuItemTabIndexed(wrapper, 0);
     });
 
-    it('should select/focus the first item', () => {
+    it('should select/focus the first item 1', () => {
       wrapper.instance().focus();
       assertMenuItemTabIndexed(wrapper, 0);
       assertMenuItemFocused(wrapper, 0);
@@ -85,7 +85,7 @@ describe('<MenuList> integration', () => {
       assertMenuItemFocused(wrapper, 0);
     });
 
-    it('should focus the second item', () => {
+    it('should focus the second item 1', () => {
       wrapper.instance().focus();
       wrapper.simulate('keyDown', { which: keycode('down') });
       assertMenuItemTabIndexed(wrapper, 1);
@@ -121,13 +121,13 @@ describe('<MenuList> integration', () => {
       resetWrapper();
     });
 
-    it('should select/focus the first item', () => {
+    it('should select/focus the first item 2', () => {
       wrapper.instance().focus();
       assertMenuItemTabIndexed(wrapper, 0);
       assertMenuItemFocused(wrapper, 0);
     });
 
-    it('should focus the second item', () => {
+    it('should focus the second item 2', () => {
       wrapper.simulate('keyDown', { which: keycode('down') });
       assertMenuItemTabIndexed(wrapper, 1);
       assertMenuItemFocused(wrapper, 1);
diff --git a/packages/material-ui/test/integration/fixtures/menus/SimpleMenu.js b/packages/material-ui/test/integration/fixtures/menus/SimpleMenu.js
index 6c8c9585055f66..0477b118214d11 100644
--- a/packages/material-ui/test/integration/fixtures/menus/SimpleMenu.js
+++ b/packages/material-ui/test/integration/fixtures/menus/SimpleMenu.js
@@ -22,17 +22,15 @@ class SimpleMenu extends React.Component {
     return (
       <div>
         <Menu id="simple-menu" open={this.state.open} onClose={this.handleClose} {...this.props}>
-          {options.map((label, index) => {
-            return (
-              <MenuItem
-                key={label}
-                selected={index === this.state.selectedIndex}
-                onClick={event => this.handleMenuItemClick(event, index)}
-              >
-                {label}
-              </MenuItem>
-            );
-          })}
+          {options.map((label, index) => (
+            <MenuItem
+              key={label}
+              selected={index === this.state.selectedIndex}
+              onClick={event => this.handleMenuItemClick(event, index)}
+            >
+              {label}
+            </MenuItem>
+          ))}
         </Menu>
       </div>
     );
diff --git a/test/regressions/tests/SpeedDial/Directions.js b/test/regressions/tests/SpeedDial/Directions.js
index 530c4f8344ad5f..e92ca2905bdaf9 100644
--- a/test/regressions/tests/SpeedDial/Directions.js
+++ b/test/regressions/tests/SpeedDial/Directions.js
@@ -50,17 +50,15 @@ function SimpleSpeedDial(props) {
 
   return (
     <SpeedDial icon={<SpeedDialIcon />} open {...props}>
-      {['A', 'B', 'C'].map((name, i) => {
-        return (
-          <SpeedDialAction
-            key={name}
-            icon={<Avatar>{name}</Avatar>}
-            tooltipOpen
-            tooltipPlacement={`${tooltipPlacement[props.direction]}${secondaryPlacement[i]}`}
-            tooltipTitle={'Tooltip'}
-          />
-        );
-      })}
+      {['A', 'B', 'C'].map((name, i) => (
+        <SpeedDialAction
+          key={name}
+          icon={<Avatar>{name}</Avatar>}
+          tooltipOpen
+          tooltipPlacement={`${tooltipPlacement[props.direction]}${secondaryPlacement[i]}`}
+          tooltipTitle={'Tooltip'}
+        />
+      ))}
     </SpeedDial>
   );
 }
@@ -71,16 +69,14 @@ function Directions({ classes }) {
 
   return (
     <div className={classes.root}>
-      {['up', 'right', 'down', 'left'].map(direction => {
-        return (
-          <SimpleSpeedDial
-            key={direction}
-            ariaLabel={direction}
-            className={speedDialClassName(direction)}
-            direction={direction}
-          />
-        );
-      })}
+      {['up', 'right', 'down', 'left'].map(direction => (
+        <SimpleSpeedDial
+          key={direction}
+          ariaLabel={direction}
+          className={speedDialClassName(direction)}
+          direction={direction}
+        />
+      ))}
     </div>
   );
 }
diff --git a/yarn.lock b/yarn.lock
index 23ab7dab4f325a..0bdfa29f73589f 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -5935,6 +5935,13 @@ eslint-config-airbnb@^17.0.0:
     object.assign "^4.1.0"
     object.entries "^1.0.4"
 
+eslint-config-prettier@^3.3.0:
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/eslint-config-prettier/-/eslint-config-prettier-3.3.0.tgz#41afc8d3b852e757f06274ed6c44ca16f939a57d"
+  integrity sha512-Bc3bh5bAcKNvs3HOpSi6EfGA2IIp7EzWcg2tS4vP7stnXu/J1opihHDM7jI9JCIckyIDTgZLSWn7J3HY0j2JfA==
+  dependencies:
+    get-stdin "^6.0.0"
+
 eslint-import-resolver-node@^0.3.1:
   version "0.3.2"
   resolved "https://registry.yarnpkg.com/eslint-import-resolver-node/-/eslint-import-resolver-node-0.3.2.tgz#58f15fb839b8d0576ca980413476aab2472db66a"
@@ -6877,6 +6884,11 @@ get-stdin@^4.0.1:
   resolved "https://registry.yarnpkg.com/get-stdin/-/get-stdin-4.0.1.tgz#b968c6b0a04384324902e8bf1a5df32579a450fe"
   integrity sha1-uWjGsKBDhDJJAui/Gl3zJXmkUP4=
 
+get-stdin@^6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/get-stdin/-/get-stdin-6.0.0.tgz#9e09bf712b360ab9225e812048f71fde9c89657b"
+  integrity sha512-jp4tHawyV7+fkkSKyvjuLZswblUtz+SQKzSWnBbii16BuZksJlU1wuBYXY75r+duh/llF1ur6oNwi+2ZzjKZ7g==
+
 get-stream@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/get-stream/-/get-stream-3.0.0.tgz#8e943d1358dc37555054ecbe2edb05aa174ede14"