"No repeated property names" error in object literals is duplicated in strict mode

src/compiler/binder.ts

@@ -2066,12 +2066,6 @@ namespace ts {
                         seen.set(identifier.escapedText, currentKind);
                         continue;
                     }
-
-                    if (currentKind === ElementKind.Property && existingKind === ElementKind.Property) {
-                        const span = getErrorSpanForNode(file, identifier);
-                        file.bindDiagnostics.push(createFileDiagnostic(file, span.start, span.length,
-                            Diagnostics.An_object_literal_cannot_have_multiple_properties_with_the_same_name_in_strict_mode));
-                    }
                 }
             }
 

src/compiler/checker.ts

@@ -43126,9 +43126,12 @@ namespace ts {
                         seen.set(effectiveName, currentKind);
                     }
                     else {
-                        if ((currentKind & DeclarationMeaning.PropertyAssignmentOrMethod) && (existingKind & DeclarationMeaning.PropertyAssignmentOrMethod)) {
+                        if ((currentKind & DeclarationMeaning.Method) && (existingKind & DeclarationMeaning.Method)) {
                             grammarErrorOnNode(name, Diagnostics.Duplicate_identifier_0, getTextOfNode(name));
                         }
+                        else if ((currentKind & DeclarationMeaning.PropertyAssignment) && (existingKind & DeclarationMeaning.PropertyAssignment)) {
+                            grammarErrorOnNode(name, Diagnostics.An_object_literal_cannot_have_multiple_properties_with_the_same_name, getTextOfNode(name));
+                        }
                         else if ((currentKind & DeclarationMeaning.GetOrSetAccessor) && (existingKind & DeclarationMeaning.GetOrSetAccessor)) {
                             if (existingKind !== DeclarationMeaning.GetOrSetAccessor && currentKind !== existingKind) {
                                 seen.set(effectiveName, currentKind | existingKind);

src/compiler/diagnosticMessages.json

@@ -335,7 +335,7 @@
         "category": "Error",
         "code": 1116
     },
-    "An object literal cannot have multiple properties with the same name in strict mode.": {
+    "An object literal cannot have multiple properties with the same name.": {
         "category": "Error",
         "code": 1117
     },

tests/baselines/reference/duplicateIdentifierDifferentSpelling.errors.txt

@@ -1,5 +1,5 @@
 tests/cases/compiler/duplicateIdentifierDifferentSpelling.ts(3,3): error TS2300: Duplicate identifier '3'.
-tests/cases/compiler/duplicateIdentifierDifferentSpelling.ts(6,21): error TS2300: Duplicate identifier '3'.
+tests/cases/compiler/duplicateIdentifierDifferentSpelling.ts(6,21): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
 ==== tests/cases/compiler/duplicateIdentifierDifferentSpelling.ts (2 errors) ====
@@ -12,5 +12,5 @@ tests/cases/compiler/duplicateIdentifierDifferentSpelling.ts(6,21): error TS2300
 
     var X = { 0b11: '', 3: '' };
                         ~
-!!! error TS2300: Duplicate identifier '3'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
 

tests/baselines/reference/duplicateObjectLiteralProperty.errors.txt

@@ -1,7 +1,7 @@
-tests/cases/compiler/duplicateObjectLiteralProperty.ts(4,5): error TS2300: Duplicate identifier 'a'.
-tests/cases/compiler/duplicateObjectLiteralProperty.ts(5,5): error TS2300: Duplicate identifier '\u0061'.
-tests/cases/compiler/duplicateObjectLiteralProperty.ts(6,5): error TS2300: Duplicate identifier 'a'.
-tests/cases/compiler/duplicateObjectLiteralProperty.ts(8,9): error TS2300: Duplicate identifier '"c"'.
+tests/cases/compiler/duplicateObjectLiteralProperty.ts(4,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty.ts(5,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty.ts(6,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty.ts(8,9): error TS1117: An object literal cannot have multiple properties with the same name.
 tests/cases/compiler/duplicateObjectLiteralProperty.ts(14,9): error TS2300: Duplicate identifier 'a'.
 tests/cases/compiler/duplicateObjectLiteralProperty.ts(15,9): error TS2300: Duplicate identifier 'a'.
 tests/cases/compiler/duplicateObjectLiteralProperty.ts(16,9): error TS1118: An object literal cannot have multiple get/set accessors with the same name.
@@ -14,17 +14,17 @@ tests/cases/compiler/duplicateObjectLiteralProperty.ts(16,9): error TS2300: Dupl
         b: true, // OK
         a: 56,   // Duplicate
         ~
-!!! error TS2300: Duplicate identifier 'a'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
         \u0061: "ss", // Duplicate
         ~~~~~~
-!!! error TS2300: Duplicate identifier '\u0061'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
         a: {
         ~
-!!! error TS2300: Duplicate identifier 'a'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
             c: 1,
             "c": 56, // Duplicate
             ~~~
-!!! error TS2300: Duplicate identifier '"c"'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
         }
     };
 

tests/baselines/reference/duplicateObjectLiteralProperty_computedName.errors.txt

@@ -1,31 +1,31 @@
-tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(3,5): error TS2300: Duplicate identifier '[1]'.
-tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(8,5): error TS2300: Duplicate identifier '[+1]'.
-tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(13,5): error TS2300: Duplicate identifier '[+1]'.
-tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(23,5): error TS2300: Duplicate identifier '["+1"]'.
-tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(28,5): error TS2300: Duplicate identifier '[-1]'.
-tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(33,5): error TS2300: Duplicate identifier '["-1"]'.
+tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(3,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(8,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(13,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(23,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(28,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(33,5): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
 ==== tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts (6 errors) ====
     const t1 = {
         1: 1,
         [1]: 0 // duplicate
         ~~~
-!!! error TS2300: Duplicate identifier '[1]'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 
     const t2 = {
         1: 1,
         [+1]: 0 // duplicate
         ~~~~
-!!! error TS2300: Duplicate identifier '[+1]'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 
     const t3 = {
         "1": 1,
         [+1]: 0 // duplicate
         ~~~~
-!!! error TS2300: Duplicate identifier '[+1]'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 
     const t4 = {
@@ -37,20 +37,20 @@ tests/cases/compiler/duplicateObjectLiteralProperty_computedName.ts(33,5): error
         "+1": 1,
         ["+1"]: 0 // duplicate
         ~~~~~~
-!!! error TS2300: Duplicate identifier '["+1"]'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 
     const t6 = {
         "-1": 1,
         [-1]: 0 // duplicate
         ~~~~
-!!! error TS2300: Duplicate identifier '[-1]'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 
     const t7 = {
         "-1": 1,
         ["-1"]: 0 // duplicate
         ~~~~~~
-!!! error TS2300: Duplicate identifier '["-1"]'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 

tests/baselines/reference/duplicatePropertiesInStrictMode.errors.txt

@@ -1,14 +1,11 @@
-tests/cases/compiler/duplicatePropertiesInStrictMode.ts(4,3): error TS1117: An object literal cannot have multiple properties with the same name in strict mode.
-tests/cases/compiler/duplicatePropertiesInStrictMode.ts(4,3): error TS2300: Duplicate identifier 'x'.
+tests/cases/compiler/duplicatePropertiesInStrictMode.ts(4,3): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
-==== tests/cases/compiler/duplicatePropertiesInStrictMode.ts (2 errors) ====
+==== tests/cases/compiler/duplicatePropertiesInStrictMode.ts (1 errors) ====
     "use strict";
     var x = {
       x: 1,
       x: 2
       ~
-!!! error TS1117: An object literal cannot have multiple properties with the same name in strict mode.
-      ~
-!!! error TS2300: Duplicate identifier 'x'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }

tests/baselines/reference/duplicatePropertyNames.errors.txt

@@ -12,8 +12,8 @@ tests/cases/conformance/types/members/duplicatePropertyNames.ts(35,5): error TS2
 tests/cases/conformance/types/members/duplicatePropertyNames.ts(36,5): error TS2300: Duplicate identifier 'foo'.
 tests/cases/conformance/types/members/duplicatePropertyNames.ts(38,5): error TS2300: Duplicate identifier 'bar'.
 tests/cases/conformance/types/members/duplicatePropertyNames.ts(39,5): error TS2300: Duplicate identifier 'bar'.
-tests/cases/conformance/types/members/duplicatePropertyNames.ts(44,5): error TS2300: Duplicate identifier 'foo'.
-tests/cases/conformance/types/members/duplicatePropertyNames.ts(46,5): error TS2300: Duplicate identifier 'bar'.
+tests/cases/conformance/types/members/duplicatePropertyNames.ts(44,5): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/conformance/types/members/duplicatePropertyNames.ts(46,5): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
 ==== tests/cases/conformance/types/members/duplicatePropertyNames.ts (16 errors) ====
@@ -90,10 +90,10 @@ tests/cases/conformance/types/members/duplicatePropertyNames.ts(46,5): error TS2
         foo: '',
         foo: '',
         ~~~
-!!! error TS2300: Duplicate identifier 'foo'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
         bar: () => { },
         bar: () => { }
         ~~~
-!!! error TS2300: Duplicate identifier 'bar'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 

tests/baselines/reference/jsFileCompilationBindStrictModeErrors.errors.txt

@@ -1,5 +1,4 @@
-tests/cases/compiler/a.js(5,5): error TS1117: An object literal cannot have multiple properties with the same name in strict mode.
-tests/cases/compiler/a.js(5,5): error TS2300: Duplicate identifier 'a'.
+tests/cases/compiler/a.js(5,5): error TS1117: An object literal cannot have multiple properties with the same name.
 tests/cases/compiler/a.js(7,5): error TS1212: Identifier expected. 'let' is a reserved word in strict mode.
 tests/cases/compiler/a.js(8,8): error TS1102: 'delete' cannot be called on an identifier in strict mode.
 tests/cases/compiler/a.js(8,8): error TS2703: The operand of a 'delete' operator must be a property reference.
@@ -15,16 +14,14 @@ tests/cases/compiler/d.js(2,9): error TS1121: Octal literals are not allowed in
 tests/cases/compiler/d.js(2,11): error TS1005: ',' expected.
 
 
-==== tests/cases/compiler/a.js (9 errors) ====
+==== tests/cases/compiler/a.js (8 errors) ====
     "use strict";
     var a = {
         a: "hello", // error
         b: 10,
         a: 10 // error
         ~
-!!! error TS1117: An object literal cannot have multiple properties with the same name in strict mode.
-        ~
-!!! error TS2300: Duplicate identifier 'a'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     };
     var let = 10; // error
         ~~~

tests/baselines/reference/lastPropertyInLiteralWins.errors.txt

@@ -1,9 +1,9 @@
 tests/cases/compiler/lastPropertyInLiteralWins.ts(8,5): error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
   Types of parameters 'num' and 'str' are incompatible.
     Type 'string' is not assignable to type 'number'.
-tests/cases/compiler/lastPropertyInLiteralWins.ts(9,5): error TS2300: Duplicate identifier 'thunk'.
+tests/cases/compiler/lastPropertyInLiteralWins.ts(9,5): error TS1117: An object literal cannot have multiple properties with the same name.
 tests/cases/compiler/lastPropertyInLiteralWins.ts(9,5): error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
-tests/cases/compiler/lastPropertyInLiteralWins.ts(14,5): error TS2300: Duplicate identifier 'thunk'.
+tests/cases/compiler/lastPropertyInLiteralWins.ts(14,5): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
 ==== tests/cases/compiler/lastPropertyInLiteralWins.ts (4 errors) ====
@@ -22,7 +22,7 @@ tests/cases/compiler/lastPropertyInLiteralWins.ts(14,5): error TS2300: Duplicate
 !!! related TS6500 tests/cases/compiler/lastPropertyInLiteralWins.ts:2:5: The expected type comes from property 'thunk' which is declared here on type 'Thing'
         thunk: (num: number) => {}
         ~~~~~
-!!! error TS2300: Duplicate identifier 'thunk'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
         ~~~~~
 !!! error TS2322: Type '(num: number) => void' is not assignable to type '(str: string) => void'.
 !!! related TS6500 tests/cases/compiler/lastPropertyInLiteralWins.ts:2:5: The expected type comes from property 'thunk' which is declared here on type 'Thing'
@@ -32,6 +32,6 @@ tests/cases/compiler/lastPropertyInLiteralWins.ts(14,5): error TS2300: Duplicate
         thunk: (num: number) => {},
         thunk: (str: string) => {}
         ~~~~~
-!!! error TS2300: Duplicate identifier 'thunk'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     });
 

tests/baselines/reference/memberOverride.errors.txt

@@ -1,4 +1,4 @@
-tests/cases/compiler/memberOverride.ts(5,5): error TS2300: Duplicate identifier 'a'.
+tests/cases/compiler/memberOverride.ts(5,5): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
 ==== tests/cases/compiler/memberOverride.ts (1 errors) ====
@@ -8,7 +8,7 @@ tests/cases/compiler/memberOverride.ts(5,5): error TS2300: Duplicate identifier
         a: "", 
         a: 5
         ~
-!!! error TS2300: Duplicate identifier 'a'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }
 
     var n: number = x.a;

tests/baselines/reference/noRepeatedPropertyNames.errors.txt

@@ -0,0 +1,18 @@
+tests/cases/compiler/noRepeatedPropertyNames.ts(2,23): error TS1117: An object literal cannot have multiple properties with the same name.
+tests/cases/compiler/noRepeatedPropertyNames.ts(5,32): error TS1117: An object literal cannot have multiple properties with the same name.
+
+
+==== tests/cases/compiler/noRepeatedPropertyNames.ts (2 errors) ====
+    // https://github.com/microsoft/TypeScript/issues/46815
+    const first = { a: 1, a: 2 };
+                          ~
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
+    class C {
+        m() {
+            const second = { a: 1, a: 2 };
+                                   ~
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
+            return second.a;
+        }
+    }
+

tests/baselines/reference/noRepeatedPropertyNames.js

@@ -0,0 +1,23 @@
+//// [noRepeatedPropertyNames.ts]
+// https://github.com/microsoft/TypeScript/issues/46815
+const first = { a: 1, a: 2 };
+class C {
+    m() {
+        const second = { a: 1, a: 2 };
+        return second.a;
+    }
+}
+
+
+//// [noRepeatedPropertyNames.js]
+// https://github.com/microsoft/TypeScript/issues/46815
+var first = { a: 1, a: 2 };
+var C = /** @class */ (function () {
+    function C() {
+    }
+    C.prototype.m = function () {
+        var second = { a: 1, a: 2 };
+        return second.a;
+    };
+    return C;
+}());

tests/baselines/reference/noRepeatedPropertyNames.symbols

@@ -0,0 +1,25 @@
+=== tests/cases/compiler/noRepeatedPropertyNames.ts ===
+// https://github.com/microsoft/TypeScript/issues/46815
+const first = { a: 1, a: 2 };
+>first : Symbol(first, Decl(noRepeatedPropertyNames.ts, 1, 5))
+>a : Symbol(a, Decl(noRepeatedPropertyNames.ts, 1, 15), Decl(noRepeatedPropertyNames.ts, 1, 21))
+>a : Symbol(a, Decl(noRepeatedPropertyNames.ts, 1, 15), Decl(noRepeatedPropertyNames.ts, 1, 21))
+
+class C {
+>C : Symbol(C, Decl(noRepeatedPropertyNames.ts, 1, 29))
+
+    m() {
+>m : Symbol(C.m, Decl(noRepeatedPropertyNames.ts, 2, 9))
+
+        const second = { a: 1, a: 2 };
+>second : Symbol(second, Decl(noRepeatedPropertyNames.ts, 4, 13))
+>a : Symbol(a, Decl(noRepeatedPropertyNames.ts, 4, 24), Decl(noRepeatedPropertyNames.ts, 4, 30))
+>a : Symbol(a, Decl(noRepeatedPropertyNames.ts, 4, 24), Decl(noRepeatedPropertyNames.ts, 4, 30))
+
+        return second.a;
+>second.a : Symbol(a, Decl(noRepeatedPropertyNames.ts, 4, 24), Decl(noRepeatedPropertyNames.ts, 4, 30))
+>second : Symbol(second, Decl(noRepeatedPropertyNames.ts, 4, 13))
+>a : Symbol(a, Decl(noRepeatedPropertyNames.ts, 4, 24), Decl(noRepeatedPropertyNames.ts, 4, 30))
+    }
+}
+

tests/baselines/reference/noRepeatedPropertyNames.types

@@ -0,0 +1,31 @@
+=== tests/cases/compiler/noRepeatedPropertyNames.ts ===
+// https://github.com/microsoft/TypeScript/issues/46815
+const first = { a: 1, a: 2 };
+>first : { a: number; }
+>{ a: 1, a: 2 } : { a: number; }
+>a : number
+>1 : 1
+>a : number
+>2 : 2
+
+class C {
+>C : C
+
+    m() {
+>m : () => number
+
+        const second = { a: 1, a: 2 };
+>second : { a: number; }
+>{ a: 1, a: 2 } : { a: number; }
+>a : number
+>1 : 1
+>a : number
+>2 : 2
+
+        return second.a;
+>second.a : number
+>second : { a: number; }
+>a : number
+    }
+}
+

tests/baselines/reference/numericStringNamedPropertyEquivalence.errors.txt

@@ -4,7 +4,7 @@ tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericString
 tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericStringNamedPropertyEquivalence.ts(16,5): error TS2300: Duplicate identifier '1'.
 tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericStringNamedPropertyEquivalence.ts(17,5): error TS2300: Duplicate identifier '1'.
 tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericStringNamedPropertyEquivalence.ts(17,5): error TS2717: Subsequent property declarations must have the same type.  Property '1.0' must be of type 'number', but here has type 'string'.
-tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericStringNamedPropertyEquivalence.ts(22,5): error TS2300: Duplicate identifier '0'.
+tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericStringNamedPropertyEquivalence.ts(22,5): error TS1117: An object literal cannot have multiple properties with the same name.
 
 
 ==== tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericStringNamedPropertyEquivalence.ts (7 errors) ====
@@ -44,5 +44,5 @@ tests/cases/conformance/types/objectTypeLiteral/propertySignatures/numericString
         "0": '',
         0: ''
         ~
-!!! error TS2300: Duplicate identifier '0'.
+!!! error TS1117: An object literal cannot have multiple properties with the same name.
     }