[Autocomplete] onInputChange it's fired in wrong moments

[sclavijo93]

I don't know if I'm not understanding how it works or it's a bug, but onInputChange is executed when the component is mounted and when the TextField loses the focus.

• The issue is present in the latest release.
• I have searched the issues of this repository and believe that this is not a duplicate.

Current Behavior 😯

onInputChange is been fired when the component is mounted and when the TextField loses the focus.

Expected Behavior 🤔

onInputChange has to be fired only when the TextField has really fired

Steps to Reproduce 🕹

Steps:

1. codesandbox.io reproduction
2. The alert shows up when the page is fully loaded.
3. Click on the TextField and then click outside.
4. The alert shows up again.

Your Environment 🌎

Tech	Version
Material-UI	v4.7.0
React	v16.10.2
Browser	Chrome v78.0.3904.108 (64 bits)

[oliviertassinari]

@sclavijo93 How does it cause an issue in your end?

[oliviertassinari]

I guess we could only trigger the event if the value actually changes. Would it solve your problem?

diff --git a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
index f833a0c0c..cc44ea60a 100644
--- a/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
+++ b/packages/material-ui-lab/src/useAutocomplete/useAutocomplete.js
@@ -210,6 +210,10 @@ export default function useAutocomplete(props) {
       newInputValue = typeof optionLabel === 'string' ? optionLabel : '';
     }

+    if (inputValue === newInputValue) {
+      return;
+    }
+
     setInputValue(newInputValue);

     if (onInputChange) {
@@ -635,6 +639,10 @@ export default function useAutocomplete(props) {
       handleOpen(event);
     }

+    if (inputValue === newValue) {
+      return;
+    }
+
     setInputValue(newValue);

     if (onInputChange) {

[sclavijo93]

@oliviertassinari it's referenced by #18559 because I'm trying to show the CircularProgress when the user types in the text field, but right now the CircularProgress is showed not only when the user types