From 941d97c45a37d0ac6a2b6ba8a6806933b14df856 Mon Sep 17 00:00:00 2001
From: Sheetal Nandi <shkamat@microsoft.com>
Date: Fri, 9 Nov 2018 16:41:18 -0800
Subject: [PATCH] Handle global augmentation in the module

---
 src/compiler/builderState.ts             | 20 +++++-
 src/testRunner/unittests/tscWatchMode.ts | 85 +++++++++++++++---------
 2 files changed, 71 insertions(+), 34 deletions(-)

diff --git a/src/compiler/builderState.ts b/src/compiler/builderState.ts
index 7cd67d99f72..7c7bebde9f9 100644
--- a/src/compiler/builderState.ts
+++ b/src/compiler/builderState.ts
@@ -368,7 +368,7 @@ namespace ts.BuilderState {
         }
 
         // If this is non module emit, or its a global file, it depends on all the source files
-        if (!state.referencedMap || (!isExternalModule(sourceFile) && !containsOnlyAmbientModules(sourceFile))) {
+        if (!state.referencedMap || isFileAffectingGlobalScope(sourceFile)) {
             return getAllFileNames(state, programOfThisState);
         }
 
@@ -430,6 +430,22 @@ namespace ts.BuilderState {
         return true;
     }
 
+    /**
+     * Return true if file contains anything that augments to global scope we need to build them as if
+     * they are global files as well as module
+     */
+    function containsGlobalScopeAugmentation(sourceFile: SourceFile) {
+        return some(sourceFile.moduleAugmentations, augmentation => isGlobalScopeAugmentation(augmentation.parent as ModuleDeclaration));
+    }
+
+    /**
+     * Return true if the file will invalidate all files because it affectes global scope
+     */
+    function isFileAffectingGlobalScope(sourceFile: SourceFile) {
+        return containsGlobalScopeAugmentation(sourceFile) ||
+            !isExternalModule(sourceFile) && !containsOnlyAmbientModules(sourceFile);
+    }
+
     /**
      * Gets all files of the program excluding the default library file
      */
@@ -473,7 +489,7 @@ namespace ts.BuilderState {
      * When program emits modular code, gets the files affected by the sourceFile whose shape has changed
      */
     function getFilesAffectedByUpdatedShapeWhenModuleEmit(state: BuilderState, programOfThisState: Program, sourceFileWithUpdatedShape: SourceFile, cacheToUpdateSignature: Map<string>, cancellationToken: CancellationToken | undefined, computeHash: ComputeHash | undefined, exportedModulesMapCache: ComputingExportedModulesMap | undefined) {
-        if (!isExternalModule(sourceFileWithUpdatedShape) && !containsOnlyAmbientModules(sourceFileWithUpdatedShape)) {
+        if (isFileAffectingGlobalScope(sourceFileWithUpdatedShape)) {
             return getAllFilesExcludingDefaultLibraryFile(state, programOfThisState, sourceFileWithUpdatedShape);
         }
 
diff --git a/src/testRunner/unittests/tscWatchMode.ts b/src/testRunner/unittests/tscWatchMode.ts
index 1e65e7b9e99..65f64b9da78 100644
--- a/src/testRunner/unittests/tscWatchMode.ts
+++ b/src/testRunner/unittests/tscWatchMode.ts
@@ -1565,15 +1565,13 @@ export class Data2 {
             });
         });
 
-        describe("updates errors in lib file when non module file changes", () => {
+        describe("updates errors in lib file", () => {
             const currentDirectory = "/user/username/projects/myproject";
             const field = "fullscreen";
-            const aFile: File = {
-                path: `${currentDirectory}/a.ts`,
-                content: `interface Document {
+            const fieldWithoutReadonly = `interface Document {
 	${field}: boolean;
-}`
-            };
+}`;
+
             const libFileWithDocument: File = {
                 path: libFile.path,
                 content: `${libFile.content}
@@ -1586,40 +1584,63 @@ interface Document {
                 return getDiagnosticOfFileFromProgram(program, file.path, file.content.indexOf(field), field.length, Diagnostics.All_declarations_of_0_must_have_identical_modifiers, field);
             }
 
-            const files = [aFile, libFileWithDocument];
+            function verifyLibFileErrorsWith(aFile: File) {
+                const files = [aFile, libFileWithDocument];
 
-            function verifyLibErrors(options: CompilerOptions) {
-                const host = createWatchedSystem(files, { currentDirectory });
-                const watch = createWatchOfFilesAndCompilerOptions([aFile.path], host, options);
-                checkProgramActualFiles(watch(), [aFile.path, libFile.path]);
-                checkOutputErrorsInitial(host, getErrors());
+                function verifyLibErrors(options: CompilerOptions) {
+                    const host = createWatchedSystem(files, { currentDirectory });
+                    const watch = createWatchOfFilesAndCompilerOptions([aFile.path], host, options);
+                    checkProgramActualFiles(watch(), [aFile.path, libFile.path]);
+                    checkOutputErrorsInitial(host, getErrors());
 
-                host.writeFile(aFile.path, "var x = 10;");
-                host.runQueuedTimeoutCallbacks();
-                checkProgramActualFiles(watch(), [aFile.path, libFile.path]);
-                checkOutputErrorsIncremental(host, emptyArray);
+                    host.writeFile(aFile.path, aFile.content.replace(fieldWithoutReadonly, "var x: string;"));
+                    host.runQueuedTimeoutCallbacks();
+                    checkProgramActualFiles(watch(), [aFile.path, libFile.path]);
+                    checkOutputErrorsIncremental(host, emptyArray);
 
-                host.writeFile(aFile.path, aFile.content);
-                host.runQueuedTimeoutCallbacks();
-                checkProgramActualFiles(watch(), [aFile.path, libFile.path]);
-                checkOutputErrorsIncremental(host, getErrors());
+                    host.writeFile(aFile.path, aFile.content);
+                    host.runQueuedTimeoutCallbacks();
+                    checkProgramActualFiles(watch(), [aFile.path, libFile.path]);
+                    checkOutputErrorsIncremental(host, getErrors());
 
-                function getErrors() {
-                    return [
-                        ...(options.skipLibCheck || options.skipDefaultLibCheck ? [] : [getDiagnostic(watch(), libFileWithDocument)]),
-                        getDiagnostic(watch(), aFile)
-                    ];
+                    function getErrors() {
+                        return [
+                            ...(options.skipLibCheck || options.skipDefaultLibCheck ? [] : [getDiagnostic(watch(), libFileWithDocument)]),
+                            getDiagnostic(watch(), aFile)
+                        ];
+                    }
                 }
+
+                it("with default options", () => {
+                    verifyLibErrors({});
+                });
+                it("with skipLibCheck", () => {
+                    verifyLibErrors({ skipLibCheck: true });
+                });
+                it("with skipDefaultLibCheck", () => {
+                    verifyLibErrors({ skipDefaultLibCheck: true });
+                });
             }
 
-            it("with default options", () => {
-                verifyLibErrors({});
+            describe("when non module file changes", () => {
+                const aFile: File = {
+                    path: `${currentDirectory}/a.ts`,
+                    content: `${fieldWithoutReadonly}
+var y: number;`
+                };
+                verifyLibFileErrorsWith(aFile);
             });
-            it("with skipLibCheck", () => {
-                verifyLibErrors({ skipLibCheck: true });
-            });
-            it("with skipDefaultLibCheck", () => {
-                verifyLibErrors({ skipDefaultLibCheck: true });
+
+            describe("when module file with global definitions changes", () => {
+                const aFile: File = {
+                    path: `${currentDirectory}/a.ts`,
+                    content: `export {}
+declare global {
+${fieldWithoutReadonly}
+var y: number;
+}`
+                };
+                verifyLibFileErrorsWith(aFile);
             });
         });