Only check for collisions with variabels and not properties

Author: mhegazy

src/compiler/checker.ts

@@ -6885,7 +6885,7 @@ module ts {
             }
         }
 
-        function checkCollisionsWithConstDeclarations(node: VariableDeclaration) {
+        function checkCollisionWithConstDeclarations(node: VariableDeclaration) {
             // Variable declarations are hoisted to the top of their function scope. They can shadow
             // block scoped declarations, which bind tighter. this will not be flagged as duplicate definition
             // by the binder as the declaration scope is different.
@@ -6906,10 +6906,12 @@ module ts {
             //      }
             if (node.initializer && (node.flags & NodeFlags.BlockScoped) === 0) {
                 var symbol = getSymbolOfNode(node);
-                var localDeclarationSymbol = resolveName(node, node.name.text, SymbolFlags.Variable, /*nodeNotFoundErrorMessage*/ undefined, /*nameArg*/ undefined);
-                if (localDeclarationSymbol && localDeclarationSymbol !== symbol && localDeclarationSymbol.flags & SymbolFlags.BlockScopedVariable) {
-                    if (getDeclarationFlagsFromSymbol(localDeclarationSymbol) & NodeFlags.Const) {
-                        error(node, Diagnostics.Cannot_redeclare_block_scoped_variable_0, symbolToString(localDeclarationSymbol));
+                if (symbol.flags & SymbolFlags.FunctionScopedVariable) {
+                    var localDeclarationSymbol = resolveName(node, node.name.text, SymbolFlags.Variable, /*nodeNotFoundErrorMessage*/ undefined, /*nameArg*/ undefined);
+                    if (localDeclarationSymbol && localDeclarationSymbol !== symbol && localDeclarationSymbol.flags & SymbolFlags.BlockScopedVariable) {
+                        if (getDeclarationFlagsFromSymbol(localDeclarationSymbol) & NodeFlags.Const) {
+                            error(node, Diagnostics.Cannot_redeclare_block_scoped_variable_0, symbolToString(localDeclarationSymbol));
+                        }
                     }
                 }
             }
@@ -6938,8 +6940,7 @@ module ts {
                         // Use default messages
                         checkTypeAssignableTo(checkAndMarkExpression(node.initializer), type, node, /*chainedMessage*/ undefined, /*terminalMessage*/ undefined);
                     }
-
-                    checkCollisionsWithConstDeclarations(node);
+                    checkCollisionWithConstDeclarations(node);
                 }
 
                 checkCollisionWithCapturedSuperVariable(node, node.name);

tests/baselines/reference/constDeclarationShadowedByVarDeclaration3.js

@@ -0,0 +1,21 @@
+//// [constDeclarationShadowedByVarDeclaration3.ts]
+// Ensure only checking for const declarations shadowed by vars
+class Rule {
+    public regex: RegExp = new RegExp('');
+    public name: string = '';
+
+    constructor(name: string) {
+        this.name = name;
+    }
+}
+
+//// [constDeclarationShadowedByVarDeclaration3.js]
+// Ensure only checking for const declarations shadowed by vars
+var Rule = (function () {
+    function Rule(name) {
+        this.regex = new RegExp('');
+        this.name = '';
+        this.name = name;
+    }
+    return Rule;
+})();

tests/baselines/reference/constDeclarationShadowedByVarDeclaration3.types

@@ -0,0 +1,25 @@
+=== tests/cases/compiler/constDeclarationShadowedByVarDeclaration3.ts ===
+// Ensure only checking for const declarations shadowed by vars
+class Rule {
+>Rule : Rule
+
+    public regex: RegExp = new RegExp('');
+>regex : RegExp
+>RegExp : RegExp
+>new RegExp('') : RegExp
+>RegExp : { (pattern: string, flags?: string): RegExp; new (pattern: string, flags?: string): RegExp; $1: string; $2: string; $3: string; $4: string; $5: string; $6: string; $7: string; $8: string; $9: string; lastMatch: string; }
+
+    public name: string = '';
+>name : string
+
+    constructor(name: string) {
+>name : string
+
+        this.name = name;
+>this.name = name : string
+>this.name : string
+>this : Rule
+>name : string
+>name : string
+    }
+}

tests/cases/compiler/constDeclarationShadowedByVarDeclaration3.ts

@@ -0,0 +1,9 @@
+// Ensure only checking for const declarations shadowed by vars
+class Rule {
+    public regex: RegExp = new RegExp('');
+    public name: string = '';
+
+    constructor(name: string) {
+        this.name = name;
+    }
+}