[WIP] Disallow merging of enum declarations

src/compiler/binder.ts

@@ -830,7 +830,7 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
                     let messageNeedsName = true;
 
                     if (symbol.flags & SymbolFlags.Enum || includes & SymbolFlags.Enum) {
-                        message = Diagnostics.Enum_declarations_can_only_merge_with_namespace_or_other_enum_declarations;
+                        message = Diagnostics.Enum_declarations_can_only_merge_with_namespace_declarations;
                         messageNeedsName = false;
                     }
 

src/compiler/checker.ts

@@ -2724,7 +2724,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
         function reportMergeSymbolError(target: Symbol, source: Symbol) {
             const isEitherEnum = !!(target.flags & SymbolFlags.Enum || source.flags & SymbolFlags.Enum);
             const isEitherBlockScoped = !!(target.flags & SymbolFlags.BlockScopedVariable || source.flags & SymbolFlags.BlockScopedVariable);
-            const message = isEitherEnum ? Diagnostics.Enum_declarations_can_only_merge_with_namespace_or_other_enum_declarations
+            const message = isEitherEnum ? Diagnostics.Enum_declarations_can_only_merge_with_namespace_declarations
                 : isEitherBlockScoped ? Diagnostics.Cannot_redeclare_block_scoped_variable_0
                 : Diagnostics.Duplicate_identifier_0;
             const sourceSymbolFile = source.declarations && getSourceFileOfNode(source.declarations[0]);

src/compiler/diagnosticMessages.json

@@ -2864,7 +2864,7 @@
         "category": "Error",
         "code": 2566
     },
-    "Enum declarations can only merge with namespace or other enum declarations.": {
+    "Enum declarations can only merge with namespace declarations.": {
         "category": "Error",
         "code": 2567
     },

src/compiler/types.ts

@@ -5938,7 +5938,7 @@ export const enum SymbolFlags {
     FunctionExcludes = Value & ~(Function | ValueModule | Class),
     ClassExcludes = (Value | Type) & ~(ValueModule | Interface | Function), // class-interface mergability done in checker.ts
     InterfaceExcludes = Type & ~(Interface | Class),
-    RegularEnumExcludes = (Value | Type) & ~(RegularEnum | ValueModule), // regular enums merge only with regular enums and modules
+    RegularEnumExcludes = (Value | Type) & ~ValueModule, // regular enums merge only modules
     ConstEnumExcludes = (Value | Type) & ~ConstEnum, // const enums merge only with const enums
     ValueModuleExcludes = Value & ~(Function | Class | RegularEnum | ValueModule),
     NamespaceModuleExcludes = 0,

tests/baselines/reference/api/typescript.d.ts

@@ -6489,7 +6489,7 @@ declare namespace ts {
         FunctionExcludes = 110991,
         ClassExcludes = 899503,
         InterfaceExcludes = 788872,
-        RegularEnumExcludes = 899327,
+        RegularEnumExcludes = 899583,
         ConstEnumExcludes = 899967,
         ValueModuleExcludes = 110735,
         NamespaceModuleExcludes = 0,

tests/baselines/reference/augmentedTypesClass.errors.txt

@@ -1,7 +1,7 @@
 augmentedTypesClass.ts(2,7): error TS2300: Duplicate identifier 'c1'.
 augmentedTypesClass.ts(3,5): error TS2300: Duplicate identifier 'c1'.
-augmentedTypesClass.ts(6,7): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesClass.ts(7,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+augmentedTypesClass.ts(6,7): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesClass.ts(7,6): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
 ==== augmentedTypesClass.ts (4 errors) ====
@@ -16,7 +16,7 @@ augmentedTypesClass.ts(7,6): error TS2567: Enum declarations can only merge with
     //// class then enum
     class c4 { public foo() { } }
           ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     enum c4 { One } // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.

tests/baselines/reference/augmentedTypesClass2.errors.txt

@@ -1,5 +1,5 @@
-augmentedTypesClass2.ts(16,7): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesClass2.ts(21,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+augmentedTypesClass2.ts(16,7): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesClass2.ts(21,6): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
 ==== augmentedTypesClass2.ts (2 errors) ====
@@ -20,14 +20,14 @@ augmentedTypesClass2.ts(21,6): error TS2567: Enum declarations can only merge wi
     // class then enum 
     class c33 {
           ~~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         foo() {
             return 1;
         }
     }
     enum c33 { One };
          ~~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // class then import
     class c44 {

tests/baselines/reference/augmentedTypesEnum.errors.txt

@@ -1,63 +1,63 @@
-augmentedTypesEnum.ts(2,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(3,5): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(6,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(7,10): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(9,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(10,5): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(13,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(14,7): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum.ts(18,11): error TS2432: In an enum with multiple declarations, only one declaration can omit an initializer for its first enum element.
-augmentedTypesEnum.ts(20,12): error TS2300: Duplicate identifier 'One'.
-augmentedTypesEnum.ts(21,12): error TS2300: Duplicate identifier 'One'.
-augmentedTypesEnum.ts(21,12): error TS2432: In an enum with multiple declarations, only one declaration can omit an initializer for its first enum element.
+augmentedTypesEnum.ts(2,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(3,5): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(6,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(7,10): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(9,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(10,5): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(13,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(14,7): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(17,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(18,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(20,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum.ts(21,6): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
 ==== augmentedTypesEnum.ts (12 errors) ====
     // enum then var
     enum e1111 { One } // error
          ~~~~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     var e1111 = 1; // error
         ~~~~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // enum then function
     enum e2 { One } // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     function e2() { } // error
              ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     enum e3 { One } // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     var e3 = () => { } // error
         ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // enum then class
     enum e4 { One } // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     class e4 { public foo() { } } // error
           ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // enum then enum
     enum e5 { One }
+         ~~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     enum e5 { Two } // error
-              ~~~
-!!! error TS2432: In an enum with multiple declarations, only one declaration can omit an initializer for its first enum element.
+         ~~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     enum e5a { One } // error
-               ~~~
-!!! error TS2300: Duplicate identifier 'One'.
+         ~~~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     enum e5a { One } // error
-               ~~~
-!!! error TS2300: Duplicate identifier 'One'.
-               ~~~
-!!! error TS2432: In an enum with multiple declarations, only one declaration can omit an initializer for its first enum element.
+         ~~~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // enum then internal module
     enum e6 { One } 

tests/baselines/reference/augmentedTypesEnum.symbols

@@ -35,19 +35,19 @@ class e4 { public foo() { } } // error
 
 // enum then enum
 enum e5 { One }
->e5 : Symbol(e5, Decl(augmentedTypesEnum.ts, 13, 29), Decl(augmentedTypesEnum.ts, 16, 15))
+>e5 : Symbol(e5, Decl(augmentedTypesEnum.ts, 13, 29))
 >One : Symbol(e5.One, Decl(augmentedTypesEnum.ts, 16, 9))
 
 enum e5 { Two } // error
->e5 : Symbol(e5, Decl(augmentedTypesEnum.ts, 13, 29), Decl(augmentedTypesEnum.ts, 16, 15))
+>e5 : Symbol(e5, Decl(augmentedTypesEnum.ts, 16, 15))
 >Two : Symbol(e5.Two, Decl(augmentedTypesEnum.ts, 17, 9))
 
 enum e5a { One } // error
->e5a : Symbol(e5a, Decl(augmentedTypesEnum.ts, 17, 15), Decl(augmentedTypesEnum.ts, 19, 16))
+>e5a : Symbol(e5a, Decl(augmentedTypesEnum.ts, 17, 15))
 >One : Symbol(e5a.One, Decl(augmentedTypesEnum.ts, 19, 10))
 
 enum e5a { One } // error
->e5a : Symbol(e5a, Decl(augmentedTypesEnum.ts, 17, 15), Decl(augmentedTypesEnum.ts, 19, 16))
+>e5a : Symbol(e5a, Decl(augmentedTypesEnum.ts, 19, 16))
 >One : Symbol(e5a.One, Decl(augmentedTypesEnum.ts, 20, 10))
 
 // enum then internal module

tests/baselines/reference/augmentedTypesEnum.types

@@ -60,7 +60,7 @@ enum e5 { One }
 enum e5 { Two } // error
 >e5 : e5
 >   : ^^
->Two : e5.One
+>Two : e5.Two
 >    : ^^^^^^
 
 enum e5a { One } // error

tests/baselines/reference/augmentedTypesEnum2.errors.txt

@@ -1,18 +1,18 @@
-augmentedTypesEnum2.ts(2,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum2.ts(4,11): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum2.ts(11,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesEnum2.ts(12,7): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+augmentedTypesEnum2.ts(2,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum2.ts(4,11): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum2.ts(11,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum2.ts(12,7): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
 ==== augmentedTypesEnum2.ts (4 errors) ====
     // enum then interface
     enum e1 { One } // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     interface e1 { // error
               ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         foo(): void;
     }
 
@@ -21,10 +21,10 @@ augmentedTypesEnum2.ts(12,7): error TS2567: Enum declarations can only merge wit
     // enum then class
     enum e2 { One }; // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     class e2 { // error
           ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         foo() {
             return 1;
         }

tests/baselines/reference/augmentedTypesEnum3.errors.txt

@@ -1,7 +1,9 @@
-augmentedTypesEnum3.ts(16,5): error TS2432: In an enum with multiple declarations, only one declaration can omit an initializer for its first enum element.
+augmentedTypesEnum3.ts(9,8): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum3.ts(12,6): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesEnum3.ts(15,6): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
-==== augmentedTypesEnum3.ts (1 errors) ====
+==== augmentedTypesEnum3.ts (3 errors) ====
     module E {
         var t;
     }
@@ -11,15 +13,19 @@ augmentedTypesEnum3.ts(16,5): error TS2432: In an enum with multiple declaration
     module F { var t; }
 
     module A {
+           ~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         var o;
     }
     enum A {
+         ~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         b
     }
     enum A {
+         ~
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         c
-        ~
-!!! error TS2432: In an enum with multiple declarations, only one declaration can omit an initializer for its first enum element.
     }
     module A {
         var p;

tests/baselines/reference/augmentedTypesEnum3.symbols

@@ -18,25 +18,25 @@ module F { var t; }
 >t : Symbol(t, Decl(augmentedTypesEnum3.ts, 6, 14))
 
 module A {
->A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 13, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
+>A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
 
     var o;
 >o : Symbol(o, Decl(augmentedTypesEnum3.ts, 9, 7))
 }
 enum A {
->A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 13, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
+>A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
 
     b
 >b : Symbol(A.b, Decl(augmentedTypesEnum3.ts, 11, 8))
 }
 enum A {
->A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 13, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
+>A : Symbol(A, Decl(augmentedTypesEnum3.ts, 13, 1))
 
     c
 >c : Symbol(A.c, Decl(augmentedTypesEnum3.ts, 14, 8))
 }
 module A {
->A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 13, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
+>A : Symbol(A, Decl(augmentedTypesEnum3.ts, 6, 19), Decl(augmentedTypesEnum3.ts, 10, 1), Decl(augmentedTypesEnum3.ts, 16, 1))
 
     var p;
 >p : Symbol(p, Decl(augmentedTypesEnum3.ts, 18, 7))

tests/baselines/reference/augmentedTypesEnum3.types

@@ -44,7 +44,7 @@ enum A {
 >  : ^
 
     c
->c : A.b
+>c : A.c
 >  : ^^^
 }
 module A {

tests/baselines/reference/augmentedTypesFunction.errors.txt

@@ -8,8 +8,8 @@ augmentedTypesFunction.ts(13,10): error TS2814: Function with bodies can only me
 augmentedTypesFunction.ts(14,7): error TS2813: Class declaration cannot implement overload list for 'y3'.
 augmentedTypesFunction.ts(16,10): error TS2814: Function with bodies can only merge with classes that are ambient.
 augmentedTypesFunction.ts(17,7): error TS2813: Class declaration cannot implement overload list for 'y3a'.
-augmentedTypesFunction.ts(20,10): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesFunction.ts(21,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+augmentedTypesFunction.ts(20,10): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesFunction.ts(21,6): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
 ==== augmentedTypesFunction.ts (12 errors) ====
@@ -58,10 +58,10 @@ augmentedTypesFunction.ts(21,6): error TS2567: Enum declarations can only merge
     // function then enum
     function y4() { } // error
              ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
     enum y4 { One } // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // function then internal module
     function y5() { }

tests/baselines/reference/augmentedTypesInterface.errors.txt

@@ -1,5 +1,5 @@
-augmentedTypesInterface.ts(23,11): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
-augmentedTypesInterface.ts(26,6): error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+augmentedTypesInterface.ts(23,11): error TS2567: Enum declarations can only merge with namespace declarations.
+augmentedTypesInterface.ts(26,6): error TS2567: Enum declarations can only merge with namespace declarations.
 
 
 ==== augmentedTypesInterface.ts (2 errors) ====
@@ -27,12 +27,12 @@ augmentedTypesInterface.ts(26,6): error TS2567: Enum declarations can only merge
     // interface then enum
     interface i3 { // error
               ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
         foo(): void;
     }
     enum i3 { One }; // error
          ~~
-!!! error TS2567: Enum declarations can only merge with namespace or other enum declarations.
+!!! error TS2567: Enum declarations can only merge with namespace declarations.
 
     // interface then import
     interface i4 {