Merge branch 'master' into disallow-global-umd-merges

Resolve the alias of the target symbol in mergeSymbol, then use the
resolved flags to determine if the merge is allowed.

This disallows UMD export merges with declarations in the global
namespace.

src/compiler/checker.ts

@@ -1026,7 +1026,8 @@ namespace ts {
          * If target is not transient, mergeSymbol will produce a transient clone, mutate that and return it.
          */
         function mergeSymbol(target: Symbol, source: Symbol, unidirectional = false): Symbol {
-            if (!(target.flags & getExcludedSymbolFlags(source.flags)) ||
+            const resolvedTarget = resolveSymbol(target);
+            if (!(resolvedTarget.flags & getExcludedSymbolFlags(source.flags)) ||
                 (source.flags | target.flags) & SymbolFlags.Assignment) {
                 if (source === target) {
                     // This can happen when an export assigned namespace exports something also erroneously exported at the top level
@@ -1034,7 +1035,6 @@ namespace ts {
                     return target;
                 }
                 if (!(target.flags & SymbolFlags.Transient)) {
-                    const resolvedTarget = resolveSymbol(target);
                     if (resolvedTarget === unknownSymbol) {
                         return source;
                     }
@@ -7268,10 +7268,6 @@ namespace ts {
 
             // Handle variable, parameter or property
             if (!pushTypeResolution(symbol, TypeSystemPropertyName.Type)) {
-                // Symbol is property of some kind that is merged with something - should use `getTypeOfFuncClassEnumModule` and not `getTypeOfVariableOrParameterOrProperty`
-                if (symbol.flags & SymbolFlags.ValueModule && !(symbol.flags & SymbolFlags.Assignment)) {
-                    return getTypeOfFuncClassEnumModule(symbol);
-                }
                 return reportCircularityError(symbol);
             }
             let type: Type | undefined;
@@ -7338,10 +7334,6 @@ namespace ts {
             }
 
             if (!popTypeResolution()) {
-                // Symbol is property of some kind that is merged with something - should use `getTypeOfFuncClassEnumModule` and not `getTypeOfVariableOrParameterOrProperty`
-                if (symbol.flags & SymbolFlags.ValueModule && !(symbol.flags & SymbolFlags.Assignment)) {
-                    return getTypeOfFuncClassEnumModule(symbol);
-                }
                 return reportCircularityError(symbol);
             }
             return type;

tests/baselines/reference/checkMergedGlobalUMDSymbol.errors.txt

@@ -1,4 +1,5 @@
-tests/cases/compiler/global.d.ts(6,16): error TS2403: Subsequent variable declarations must have the same type.  Variable 'THREE' must be of type 'typeof import("tests/cases/compiler/global")', but here has type 'typeof import("tests/cases/compiler/three")'.
+tests/cases/compiler/global.d.ts(3,21): error TS2451: Cannot redeclare block-scoped variable 'THREE'.
+tests/cases/compiler/global.d.ts(6,16): error TS2451: Cannot redeclare block-scoped variable 'THREE'.
 
 
 ==== tests/cases/compiler/three.d.ts (0 errors) ====
@@ -6,16 +7,19 @@ tests/cases/compiler/global.d.ts(6,16): error TS2403: Subsequent variable declar
       export class Vector2 {}
     }
     
-==== tests/cases/compiler/global.d.ts (1 errors) ====
+==== tests/cases/compiler/global.d.ts (2 errors) ====
     import * as _three from './three';
     
     export as namespace THREE;
+                        ~~~~~
+!!! error TS2451: Cannot redeclare block-scoped variable 'THREE'.
+!!! related TS6203 tests/cases/compiler/global.d.ts:6:16: 'THREE' was also declared here.
     
     declare global {
       export const THREE: typeof _three;
                    ~~~~~
-!!! error TS2403: Subsequent variable declarations must have the same type.  Variable 'THREE' must be of type 'typeof import("tests/cases/compiler/global")', but here has type 'typeof import("tests/cases/compiler/three")'.
-!!! related TS6203 tests/cases/compiler/global.d.ts:1:1: 'THREE' was also declared here.
+!!! error TS2451: Cannot redeclare block-scoped variable 'THREE'.
+!!! related TS6203 tests/cases/compiler/global.d.ts:3:1: 'THREE' was also declared here.
     }
     
 ==== tests/cases/compiler/test.ts (0 errors) ====

tests/baselines/reference/checkMergedGlobalUMDSymbol.symbols

@@ -17,12 +17,12 @@ declare global {
 >global : Symbol(global, Decl(global.d.ts, 2, 26))
 
   export const THREE: typeof _three;
->THREE : Symbol(THREE, Decl(global.d.ts, 0, 0), Decl(global.d.ts, 5, 14))
+>THREE : Symbol(THREE, Decl(global.d.ts, 5, 14))
 >_three : Symbol(_three, Decl(global.d.ts, 0, 6))
 }
 
 === tests/cases/compiler/test.ts ===
 const m = THREE
 >m : Symbol(m, Decl(test.ts, 0, 5))
->THREE : Symbol(THREE, Decl(global.d.ts, 0, 0), Decl(global.d.ts, 5, 14))
+>THREE : Symbol(THREE, Decl(global.d.ts, 0, 34))
 

tests/baselines/reference/checkMergedGlobalUMDSymbol.types

@@ -17,12 +17,12 @@ declare global {
 >global : typeof global
 
   export const THREE: typeof _three;
->THREE : typeof import("tests/cases/compiler/global")
+>THREE : typeof _three
 >_three : typeof _three
 }
 
 === tests/cases/compiler/test.ts ===
 const m = THREE
->m : typeof import("tests/cases/compiler/global")
->THREE : typeof import("tests/cases/compiler/global")
+>m : typeof THREE
+>THREE : typeof THREE
 

tests/baselines/reference/declarationFileNoCrashOnExtraExportModifier.errors.txt

@@ -1,8 +1,9 @@
 tests/cases/compiler/input.ts(1,1): error TS2309: An export assignment cannot be used in a module with other exported elements.
-tests/cases/compiler/input.ts(6,14): error TS2323: Cannot redeclare exported variable 'Sub'.
+tests/cases/compiler/input.ts(6,14): error TS2300: Duplicate identifier 'Sub'.
+tests/cases/compiler/input.ts(12,14): error TS2300: Duplicate identifier 'Sub'.
 
 
-==== tests/cases/compiler/input.ts (2 errors) ====
+==== tests/cases/compiler/input.ts (3 errors) ====
     export = exports;
     ~~~~~~~~~~~~~~~~~
 !!! error TS2309: An export assignment cannot be used in a module with other exported elements.
@@ -12,11 +13,15 @@ tests/cases/compiler/input.ts(6,14): error TS2323: Cannot redeclare exported var
     }
     export class Sub {
                  ~~~
-!!! error TS2323: Cannot redeclare exported variable 'Sub'.
+!!! error TS2300: Duplicate identifier 'Sub'.
+!!! related TS6203 tests/cases/compiler/input.ts:12:14: 'Sub' was also declared here.
         instance!: {
             t: number;
         };
     }
     declare namespace exports {
         export { Sub };
+                 ~~~
+!!! error TS2300: Duplicate identifier 'Sub'.
+!!! related TS6203 tests/cases/compiler/input.ts:6:14: 'Sub' was also declared here.
     }

tests/baselines/reference/declarationFileNoCrashOnExtraExportModifier.symbols

@@ -12,7 +12,7 @@ declare class exports {
 >t : Symbol(exports.t, Decl(input.ts, 2, 27))
 }
 export class Sub {
->Sub : Symbol(Sub, Decl(input.ts, 4, 1), Decl(input.ts, 4, 1))
+>Sub : Symbol(Sub, Decl(input.ts, 4, 1))
 
     instance!: {
 >instance : Symbol(Sub.instance, Decl(input.ts, 5, 18))
@@ -26,5 +26,5 @@ declare namespace exports {
 >exports : Symbol(exports, Decl(input.ts, 0, 17), Decl(input.ts, 9, 1))
 
     export { Sub };
->Sub : Symbol(exports.Sub, Decl(input.ts, 11, 12))
+>Sub : Symbol(Sub, Decl(input.ts, 11, 12))
 }

tests/baselines/reference/declarationFileNoCrashOnExtraExportModifier.types

@@ -26,5 +26,5 @@ declare namespace exports {
 >exports : typeof exports
 
     export { Sub };
->Sub : typeof import("tests/cases/compiler/input").Sub
+>Sub : typeof Sub
 }

tests/baselines/reference/project/declareVariableCollision/amd/declareVariableCollision.errors.txt

@@ -1,5 +1,4 @@
-in1.d.ts(1,8): error TS2300: Duplicate identifier 'a'.
-in2.d.ts(1,8): error TS2300: Duplicate identifier 'a'.
+in2.d.ts(1,1): error TS2440: Import declaration conflicts with local declaration of 'A'.
 
 
 ==== decl.d.ts (0 errors) ====
@@ -15,13 +14,9 @@ in2.d.ts(1,8): error TS2300: Duplicate identifier 'a'.
             class MyClass{ }
         }
     }
-==== in1.d.ts (1 errors) ====
+==== in1.d.ts (0 errors) ====
     import a = A;
-           ~
-!!! error TS2300: Duplicate identifier 'a'.
-!!! related TS6203 in2.d.ts:1:8: 'a' was also declared here.
 ==== in2.d.ts (1 errors) ====
     import a = A;
-           ~
-!!! error TS2300: Duplicate identifier 'a'.
-!!! related TS6203 in1.d.ts:1:8: 'a' was also declared here.
+    ~~~~~~~~~~~~~
+!!! error TS2440: Import declaration conflicts with local declaration of 'A'.

tests/baselines/reference/project/declareVariableCollision/node/declareVariableCollision.errors.txt

@@ -1,5 +1,4 @@
-in1.d.ts(1,8): error TS2300: Duplicate identifier 'a'.
-in2.d.ts(1,8): error TS2300: Duplicate identifier 'a'.
+in2.d.ts(1,1): error TS2440: Import declaration conflicts with local declaration of 'A'.
 
 
 ==== decl.d.ts (0 errors) ====
@@ -15,13 +14,9 @@ in2.d.ts(1,8): error TS2300: Duplicate identifier 'a'.
             class MyClass{ }
         }
     }
-==== in1.d.ts (1 errors) ====
+==== in1.d.ts (0 errors) ====
     import a = A;
-           ~
-!!! error TS2300: Duplicate identifier 'a'.
-!!! related TS6203 in2.d.ts:1:8: 'a' was also declared here.
 ==== in2.d.ts (1 errors) ====
     import a = A;
-           ~
-!!! error TS2300: Duplicate identifier 'a'.
-!!! related TS6203 in1.d.ts:1:8: 'a' was also declared here.
+    ~~~~~~~~~~~~~
+!!! error TS2440: Import declaration conflicts with local declaration of 'A'.

tests/baselines/reference/umdGlobalAugmentationNoCrash.errors.txt

@@ -0,0 +1,31 @@
+tests/cases/compiler/global.d.ts(2,11): error TS2451: Cannot redeclare block-scoped variable 'React'.
+tests/cases/compiler/module.d.ts(1,21): error TS2451: Cannot redeclare block-scoped variable 'React'.
+tests/cases/compiler/some_module.ts(2,1): error TS2686: 'React' refers to a UMD global, but the current file is a module. Consider adding an import instead.
+
+
+==== tests/cases/compiler/global.d.ts (1 errors) ====
+    declare global {
+        const React: typeof import("./module");
+              ~~~~~
+!!! error TS2451: Cannot redeclare block-scoped variable 'React'.
+!!! related TS6203 /.src/tests/cases/compiler/module.d.ts:1:21: 'React' was also declared here.
+    }
+    export {};
+    
+==== tests/cases/compiler/module.d.ts (1 errors) ====
+    export as namespace React;
+                        ~~~~~
+!!! error TS2451: Cannot redeclare block-scoped variable 'React'.
+!!! related TS6203 tests/cases/compiler/global.d.ts:2:11: 'React' was also declared here.
+    export function foo(): string;
+    
+==== tests/cases/compiler/some_module.ts (1 errors) ====
+    export {}
+    React.foo;
+    ~~~~~
+!!! error TS2686: 'React' refers to a UMD global, but the current file is a module. Consider adding an import instead.
+    
+==== tests/cases/compiler/emits.ts (0 errors) ====
+    console.log("hello");
+    React.foo;
+    

tests/baselines/reference/umdGlobalAugmentationNoCrash.symbols

@@ -3,7 +3,7 @@ declare global {
 >global : Symbol(global, Decl(global.d.ts, 0, 0))
 
     const React: typeof import("./module");
->React : Symbol(React, Decl(module.d.ts, 0, 0), Decl(global.d.ts, 1, 9))
+>React : Symbol(React, Decl(global.d.ts, 1, 9))
 }
 export {};
 
@@ -18,7 +18,7 @@ export function foo(): string;
 export {}
 React.foo;
 >React.foo : Symbol(foo, Decl(module.d.ts, 0, 26))
->React : Symbol(React, Decl(module.d.ts, 0, 0), Decl(global.d.ts, 1, 9))
+>React : Symbol(React, Decl(module.d.ts, 0, 0))
 >foo : Symbol(foo, Decl(module.d.ts, 0, 26))
 
 === tests/cases/compiler/emits.ts ===
@@ -28,7 +28,7 @@ console.log("hello");
 >log : Symbol(Console.log, Decl(lib.dom.d.ts, --, --))
 
 React.foo;
->React.foo : Symbol(foo, Decl(module.d.ts, 0, 26))
->React : Symbol(React, Decl(module.d.ts, 0, 0), Decl(global.d.ts, 1, 9))
->foo : Symbol(foo, Decl(module.d.ts, 0, 26))
+>React.foo : Symbol(React.foo, Decl(module.d.ts, 0, 26))
+>React : Symbol(React, Decl(module.d.ts, 0, 0))
+>foo : Symbol(React.foo, Decl(module.d.ts, 0, 26))
 

tests/baselines/reference/umdGlobalAugmentationNoCrash.types

@@ -31,6 +31,6 @@ console.log("hello");
 
 React.foo;
 >React.foo : () => string
->React : typeof import("tests/cases/compiler/module")
+>React : typeof React
 >foo : () => string
 

tests/baselines/reference/umdNamespaceMergedWithGlobalAugmentationIsNotCircular.errors.txt

@@ -0,0 +1,33 @@
+tests/cases/compiler/global.d.ts(2,11): error TS2451: Cannot redeclare block-scoped variable 'React'.
+tests/cases/compiler/module.d.ts(2,21): error TS2451: Cannot redeclare block-scoped variable 'React'.
+
+
+==== tests/cases/compiler/global.d.ts (1 errors) ====
+    declare global {
+        const React: typeof import("./module");
+              ~~~~~
+!!! error TS2451: Cannot redeclare block-scoped variable 'React'.
+!!! related TS6203 /.src/tests/cases/compiler/module.d.ts:2:21: 'React' was also declared here.
+    }
+    
+    export { };
+    
+==== tests/cases/compiler/module.d.ts (1 errors) ====
+    export = React;
+    export as namespace React;
+                        ~~~~~
+!!! error TS2451: Cannot redeclare block-scoped variable 'React'.
+!!! related TS6203 tests/cases/compiler/global.d.ts:2:11: 'React' was also declared here.
+    
+    declare namespace React {
+        function createRef(): any;
+    }
+    
+==== tests/cases/compiler/some_module.ts (0 errors) ====
+    export { };
+    React.createRef;
+    
+==== tests/cases/compiler/emits.ts (0 errors) ====
+    console.log("hello");
+    React.createRef;
+    

tests/baselines/reference/umdNamespaceMergedWithGlobalAugmentationIsNotCircular.js

@@ -21,7 +21,8 @@ React.createRef;
 
 //// [emits.ts]
 console.log("hello");
-React.createRef;
+React.createRef;
+
 
 //// [some_module.js]
 React.createRef;

tests/baselines/reference/umdNamespaceMergedWithGlobalAugmentationIsNotCircular.symbols

@@ -3,7 +3,7 @@ declare global {
 >global : Symbol(global, Decl(global.d.ts, 0, 0))
 
     const React: typeof import("./module");
->React : Symbol(React, Decl(module.d.ts, 1, 26), Decl(global.d.ts, 1, 9))
+>React : Symbol(React, Decl(global.d.ts, 1, 9))
 }
 
 export { };
@@ -16,7 +16,7 @@ export as namespace React;
 >React : Symbol(React, Decl(module.d.ts, 0, 15))
 
 declare namespace React {
->React : Symbol(React, Decl(module.d.ts, 1, 26), Decl(global.d.ts, 1, 9))
+>React : Symbol(React, Decl(module.d.ts, 1, 26))
 
     function createRef(): any;
 >createRef : Symbol(createRef, Decl(module.d.ts, 3, 25))
@@ -26,7 +26,7 @@ declare namespace React {
 export { };
 React.createRef;
 >React.createRef : Symbol(React.createRef, Decl(module.d.ts, 3, 25))
->React : Symbol(React, Decl(module.d.ts, 1, 26), Decl(global.d.ts, 1, 9))
+>React : Symbol(React, Decl(module.d.ts, 0, 15))
 >createRef : Symbol(React.createRef, Decl(module.d.ts, 3, 25))
 
 === tests/cases/compiler/emits.ts ===
@@ -37,6 +37,6 @@ console.log("hello");
 
 React.createRef;
 >React.createRef : Symbol(React.createRef, Decl(module.d.ts, 3, 25))
->React : Symbol(React, Decl(module.d.ts, 1, 26), Decl(global.d.ts, 1, 9))
+>React : Symbol(React, Decl(module.d.ts, 0, 15))
 >createRef : Symbol(React.createRef, Decl(module.d.ts, 3, 25))
 

tests/baselines/reference/umdNamespaceMergedWithGlobalAugmentationIsNotCircular.types

@@ -3,17 +3,17 @@ declare global {
 >global : typeof global
 
     const React: typeof import("./module");
->React : typeof React
+>React : typeof import("tests/cases/compiler/module")
 }
 
 export { };
 
 === tests/cases/compiler/module.d.ts ===
 export = React;
->React : typeof import("tests/cases/compiler/module")
+>React : typeof React
 
 export as namespace React;
->React : typeof import("tests/cases/compiler/module")
+>React : typeof React
 
 declare namespace React {
 >React : typeof React
@@ -26,7 +26,7 @@ declare namespace React {
 export { };
 React.createRef;
 >React.createRef : () => any
->React : typeof React
+>React : typeof import("tests/cases/compiler/module")
 >createRef : () => any
 
 === tests/cases/compiler/emits.ts ===

tests/cases/compiler/umdNamespaceMergedWithGlobalAugmentationIsNotCircular.ts

@@ -1,4 +1,5 @@
 // @strict: true
+// @allowUmdGlobalAccess: true
 // @module: esnext
 // @moduleResolution: node
 // @target: es2018
@@ -23,4 +24,4 @@ React.createRef;
 
 // @filename: emits.ts
 console.log("hello");
-React.createRef;
+React.createRef;

tests/cases/fourslash/findAllReferencesUmdModuleAsGlobalConst.ts

@@ -1,43 +0,0 @@
-/// <reference path='fourslash.ts' />
-
-// @Filename: /node_modules/@types/three/three-core.d.ts
-////export class Vector3 {
-////    constructor(x?: number, y?: number, z?: number);
-////    x: number;
-////    y: number;
-////}
-
-// @Filename: /node_modules/@types/three/index.d.ts
-////export * from "./three-core";
-////[|export as namespace [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 0 |}THREE|];|]
-
-// @Filename: /typings/global.d.ts
-////[|import * as _THREE from '[|{| "contextRangeIndex": 2 |}three|]';|]
-////declare global {
-////    [|const [|{| "isWriteAccess": true, "isDefinition": true, "contextRangeIndex": 4 |}THREE|]: typeof _THREE;|]
-////}
-
-// @Filename: /src/index.ts
-////export const a = {};
-////let v = new [|THREE|].Vector2();
-
-// @Filename: /tsconfig.json
-////{
-////    "compilerOptions": {
-////        "esModuleInterop": true,
-////        "outDir": "./build/js/",
-////        "noImplicitAny": true,
-////        "module": "es6",
-////        "target": "es6",
-////        "allowJs": true,
-////        "skipLibCheck": true,
-////        "lib": ["es2016", "dom"],
-////        "typeRoots": ["node_modules/@types/"],
-////        "types": ["three"]
-//// 	},
-////    "files": ["/src/index.ts", "typings/global.d.ts"]
-////}
-
-const [r0Def, r0, r1Def, r1, r2Def, ...rest] = test.ranges();
-verify.singleReferenceGroup(`module THREE
-var THREE: typeof import("/node_modules/@types/three/index")`, [r0, r1, ...rest]);

tests/cases/fourslash/moduleReexportedIntoGlobalQuickInfo.ts

@@ -1,16 +0,0 @@
-/// <reference path="fourslash.ts" />
-
-// @Filename: /node_modules/@types/three/index.d.ts
-////export class Vector3 {}
-////export as namespace THREE;
-// @Filename: /global.d.ts
-////import * as _THREE from 'three';
-////
-////declare global {
-////  const THREE: typeof _THREE;
-////}
-// @Filename: /index.ts
-////let v = new /*1*/THREE.Vector3();
-
-verify.quickInfoAt("1", `module THREE
-var THREE: typeof import("/node_modules/@types/three/index")`);