Take runtime semantics of numerically named properties into account.

src/compiler/checker.ts

@@ -4663,7 +4663,28 @@ module ts {
         }
 
         function isNumericName(name: string) {
-            return (name !== "") && !isNaN(<number><any>name);
+            // The intent of numeric names is that
+            //     - they are names with text in a numeric form, and that
+            //     - setting properties/indexing with them is always equivalent to doing so with the numeric literal 'numLit',
+            //         acquired by applying the abstract 'ToNumber' operation on the name's text.
+            //
+            // The subtlety is in the latter portion, as we cannot reliably say that anything that looks like a numeric literal is a numeric name.
+            // In fact, it is the case that the text of the name must be equal to 'ToString(numLit)' for this to hold.
+            //
+            // Consider the property name '"0xF00D"'. When one indexes with '0xF00D', they are actually indexing with the value of 'ToString(0xF00D)'
+            // according to the ECMAScript specification, so it is actually as if the user indexed with the string '"61453"'.
+            // Thus, the text of all numeric literals equivalent to '61543' such as '0xF00D', '0xf00D', '0170015', etc. are not valid numeric names
+            // because their 'ToString' representation is not equal to their original text.
+            // This is motivated by ECMA-262 sections 9.3.1, 9.8.1, 11.1.5, and 11.2.1.
+            //
+            // Here, we test whether 'ToString(ToNumber(name))' is exactly equal to 'name'.
+            // The '+' prefix operator is equivalent here to applying the abstract ToNumber operation.
+            // Applying the 'toString()' method on a number gives us the abstract ToString operation on a number.
+            //
+            // Note that this accepts the values 'Infinity', '-Infinity', and 'NaN', and that this is intentional.
+            // This is desired behavior, because when indexing with them as numeric entities, you are indexing
+            // with the strings '"Infinity"', '"-Infinity"', and '"NaN"' respectively.
+            return (+name).toString() === name;
         }
 
         function checkObjectLiteral(node: ObjectLiteral, contextualMapper?: TypeMapper): Type {
@@ -4713,7 +4734,9 @@ module ts {
                         if (hasProperty(properties, id)) {
                             if (kind === IndexKind.String || isNumericName(id)) {
                                 var type = getTypeOfSymbol(properties[id]);
-                                if (!contains(propTypes, type)) propTypes.push(type);
+                                if (!contains(propTypes, type)) {
+                                    propTypes.push(type);
+                                }
                             }
                         }
                     }

tests/baselines/reference/enumIdentifierLiterals.errors.txt

@@ -1,11 +1,10 @@
 tests/cases/compiler/enumIdentifierLiterals.ts(2,5): error TS1151: An enum member cannot have a numeric name.
 tests/cases/compiler/enumIdentifierLiterals.ts(3,5): error TS1151: An enum member cannot have a numeric name.
 tests/cases/compiler/enumIdentifierLiterals.ts(4,5): error TS1151: An enum member cannot have a numeric name.
-tests/cases/compiler/enumIdentifierLiterals.ts(5,5): error TS1151: An enum member cannot have a numeric name.
 tests/cases/compiler/enumIdentifierLiterals.ts(6,5): error TS1151: An enum member cannot have a numeric name.
 
 
-==== tests/cases/compiler/enumIdentifierLiterals.ts (5 errors) ====
+==== tests/cases/compiler/enumIdentifierLiterals.ts (4 errors) ====
     enum Nums {
         1.0,
         ~~~
@@ -17,8 +16,6 @@ tests/cases/compiler/enumIdentifierLiterals.ts(6,5): error TS1151: An enum membe
         ~~~~~~
 !!! error TS1151: An enum member cannot have a numeric name.
         "13e-1",
-        ~~~~~~~
-!!! error TS1151: An enum member cannot have a numeric name.
         0xF00D
         ~~~~~~
 !!! error TS1151: An enum member cannot have a numeric name.

tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations.errors.txt

@@ -4,20 +4,17 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(90,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(93,9): error TS1056: Accessors are only available when targeting ECMAScript 5 and higher.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(18,5): error TS2412: Property '2.0' of type 'number' is not assignable to numeric index type 'string'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(20,5): error TS2412: Property '"4.0"' of type 'number' is not assignable to numeric index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(21,5): error TS2412: Property '3.0' of type 'MyNumber' is not assignable to numeric index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(50,5): error TS2412: Property '2.0' of type 'number' is not assignable to numeric index type 'string'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(55,5): error TS2412: Property '"4.0"' of type 'number' is not assignable to numeric index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(68,5): error TS2412: Property '2.0' of type 'number' is not assignable to numeric index type 'string'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(73,5): error TS2412: Property '"4.0"' of type 'number' is not assignable to numeric index type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(78,5): error TS2322: Type '{ [x: number]: string | number; 1.0: string; 2.0: number; a: string; b: number; c: () => void; "d": string; "e": number; "3.0": string; "4.0": number; f: any; X: string; foo: () => string; }' is not assignable to type '{ [x: number]: string; }':
   Index signatures are incompatible:
     Type 'string | number' is not assignable to type 'string':
       Type 'number' is not assignable to type 'string'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts(88,9): error TS2304: Cannot find name 'Myn'.
 
 
-==== tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts (14 errors) ====
+==== tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations.ts (11 errors) ====
     // String indexer types constrain the types of named properties in their containing type
 
     interface MyNumber extends Number {
@@ -40,8 +37,6 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
 !!! error TS2412: Property '2.0' of type 'number' is not assignable to numeric index type 'string'.
         "3.0": string; // ok
         "4.0": number; // error
-        ~~~~~~~~~~~~~~
-!!! error TS2412: Property '"4.0"' of type 'number' is not assignable to numeric index type 'string'.
         3.0: MyNumber // error
         ~~~~~~~~~~~~~
 !!! error TS2412: Property '3.0' of type 'MyNumber' is not assignable to numeric index type 'string'.
@@ -87,8 +82,6 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
         foo(): string; // ok
         "3.0": string; // ok
         "4.0": number; // error
-        ~~~~~~~~~~~~~~
-!!! error TS2412: Property '"4.0"' of type 'number' is not assignable to numeric index type 'string'.
         f: MyNumber; // error
     }
 
@@ -109,8 +102,6 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
         foo(): string; // ok
         "3.0": string; // ok
         "4.0": number; // error
-        ~~~~~~~~~~~~~~
-!!! error TS2412: Property '"4.0"' of type 'number' is not assignable to numeric index type 'string'.
         f: MyNumber; // error
     }
 

tests/baselines/reference/numericIndexerConstrainsPropertyDeclarations2.errors.txt

@@ -1,16 +1,13 @@
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(16,5): error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(17,5): error TS2412: Property '"4.0"' of type 'string' is not assignable to numeric index type 'A'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(25,5): error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(26,5): error TS2412: Property '"4.0"' of type 'string' is not assignable to numeric index type 'A'.
 tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(34,5): error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(35,5): error TS2412: Property '"4.0"' of type 'string' is not assignable to numeric index type 'A'.
-tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(39,5): error TS2322: Type '{ [x: number]: string | number | A; 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }':
+tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts(39,5): error TS2322: Type '{ [x: number]: number | A; 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }':
   Index signatures are incompatible:
-    Type 'string | number | A' is not assignable to type 'A':
-      Type 'string' is not assignable to type 'A'.
+    Type 'number | A' is not assignable to type 'A':
+      Type 'number' is not assignable to type 'A'.
 
 
-==== tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts (7 errors) ====
+==== tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerConstrainsPropertyDeclarations2.ts (4 errors) ====
     // String indexer providing a constraint of a user defined type
 
     class A {
@@ -30,8 +27,6 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
         ~~~~~~~~~~~~
 !!! error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
         "4.0": string; // error
-        ~~~~~~~~~~~~~~
-!!! error TS2412: Property '"4.0"' of type 'string' is not assignable to numeric index type 'A'.
     }
 
     interface Foo2 {
@@ -43,8 +38,6 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
         ~~~~~~~~~~~~
 !!! error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
         "4.0": string; // error
-        ~~~~~~~~~~~~~~
-!!! error TS2412: Property '"4.0"' of type 'string' is not assignable to numeric index type 'A'.
     }
 
     var a: {
@@ -56,17 +49,15 @@ tests/cases/conformance/types/objectTypeLiteral/indexSignatures/numericIndexerCo
         ~~~~~~~~~~~~
 !!! error TS2412: Property '3.0' of type 'number' is not assignable to numeric index type 'A'.
         "4.0": string; // error
-        ~~~~~~~~~~~~~~
-!!! error TS2412: Property '"4.0"' of type 'string' is not assignable to numeric index type 'A'.
     };
 
     // error
     var b: { [x: number]: A } = {
         ~
-!!! error TS2322: Type '{ [x: number]: string | number | A; 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }':
+!!! error TS2322: Type '{ [x: number]: number | A; 1.0: A; 2.0: B; 3.0: number; "2.5": B; "4.0": string; }' is not assignable to type '{ [x: number]: A; }':
 !!! error TS2322:   Index signatures are incompatible:
-!!! error TS2322:     Type 'string | number | A' is not assignable to type 'A':
-!!! error TS2322:       Type 'string' is not assignable to type 'A'.
+!!! error TS2322:     Type 'number | A' is not assignable to type 'A':
+!!! error TS2322:       Type 'number' is not assignable to type 'A'.
         1.0: new A(), 
         2.0: new B(), 
         "2.5": new B(),

tests/baselines/reference/propertiesAndIndexers2.errors.txt

@@ -0,0 +1,46 @@
+tests/cases/compiler/propertiesAndIndexers2.ts(2,5): error TS2413: Numeric index type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(8,5): error TS2411: Property 'c' of type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(9,5): error TS2411: Property '3' of type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(10,5): error TS2411: Property 'Infinity' of type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(11,5): error TS2411: Property '"-Infinity"' of type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(12,5): error TS2411: Property 'NaN' of type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(13,5): error TS2411: Property '"-NaN"' of type 'string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(14,5): error TS2411: Property '6' of type '() => string' is not assignable to string index type 'number'.
+tests/cases/compiler/propertiesAndIndexers2.ts(14,5): error TS2412: Property '6' of type '() => string' is not assignable to numeric index type 'string'.
+
+
+==== tests/cases/compiler/propertiesAndIndexers2.ts (9 errors) ====
+    interface A {
+        [n: number]: string;
+        ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2413: Numeric index type 'string' is not assignable to string index type 'number'.
+        [s: string]: number;
+    }
+
+    // All of these should fail.
+    interface B extends A {
+        c: string;
+        ~~~~~~~~~~
+!!! error TS2411: Property 'c' of type 'string' is not assignable to string index type 'number'.
+        3: string;
+        ~~~~~~~~~~
+!!! error TS2411: Property '3' of type 'string' is not assignable to string index type 'number'.
+        Infinity: string;
+        ~~~~~~~~~~~~~~~~~
+!!! error TS2411: Property 'Infinity' of type 'string' is not assignable to string index type 'number'.
+        "-Infinity": string;
+        ~~~~~~~~~~~~~~~~~~~~
+!!! error TS2411: Property '"-Infinity"' of type 'string' is not assignable to string index type 'number'.
+        NaN: string;
+        ~~~~~~~~~~~~
+!!! error TS2411: Property 'NaN' of type 'string' is not assignable to string index type 'number'.
+        "-NaN": string;
+        ~~~~~~~~~~~~~~~
+!!! error TS2411: Property '"-NaN"' of type 'string' is not assignable to string index type 'number'.
+        6(): string;
+        ~~~~~~~~~~~~
+!!! error TS2411: Property '6' of type '() => string' is not assignable to string index type 'number'.
+        ~~~~~~~~~~~~
+!!! error TS2412: Property '6' of type '() => string' is not assignable to numeric index type 'string'.
+    }
+

tests/baselines/reference/propertiesAndIndexers2.js

@@ -0,0 +1,19 @@
+//// [propertiesAndIndexers2.ts]
+interface A {
+    [n: number]: string;
+    [s: string]: number;
+}
+
+// All of these should fail.
+interface B extends A {
+    c: string;
+    3: string;
+    Infinity: string;
+    "-Infinity": string;
+    NaN: string;
+    "-NaN": string;
+    6(): string;
+}
+
+
+//// [propertiesAndIndexers2.js]