Added emitHost method to return source from node modules

Author: billti

src/compiler/program.ts

@@ -1361,10 +1361,8 @@ namespace ts {
                 getNewLine: () => host.getNewLine(),
                 getSourceFile: program.getSourceFile,
                 getSourceFileByPath: program.getSourceFileByPath,
-                getSourceFiles: () => filter(program.getSourceFiles(),
-                    // Remove JavaScript files found by searching node_modules from the source files to emit
-                    sourceFile => !lookUp(jsFilesFoundSearchingNodeModules, sourceFile.path)
-                ),
+                getSourceFiles: program.getSourceFiles,
+                getFilesFromNodeModules: () => jsFilesFoundSearchingNodeModules,
                 writeFile: writeFileCallback || (
                     (fileName, data, writeByteOrderMark, onError, sourceFiles) => host.writeFile(fileName, data, writeByteOrderMark, onError, sourceFiles)),
                 isEmitBlocked,

src/compiler/utilities.ts

@@ -34,6 +34,7 @@ namespace ts {
 
     export interface EmitHost extends ScriptReferenceHost {
         getSourceFiles(): SourceFile[];
+        getFilesFromNodeModules(): Map<boolean>;
 
         getCommonSourceDirectory(): string;
         getCanonicalFileName(fileName: string): string;
@@ -2274,9 +2275,10 @@ namespace ts {
         }
         else {
             const sourceFiles = targetSourceFile === undefined ? host.getSourceFiles() : [targetSourceFile];
+            const nodeModulesFiles = host.getFilesFromNodeModules();
             for (const sourceFile of sourceFiles) {
-                // Don't emit if source file is a declaration file
-                if (!isDeclarationFile(sourceFile)) {
+                // Don't emit if source file is a declaration file, or was located under node_modules
+                if (!isDeclarationFile(sourceFile) && !lookUp(nodeModulesFiles, sourceFile.path)) {
                     onSingleFileEmit(host, sourceFile);
                 }
             }
@@ -2308,11 +2310,14 @@ namespace ts {
         }
 
         function onBundledEmit(host: EmitHost) {
-            // Can emit only sources that are not declaration file and are either non module code or module with --module or --target es6 specified
+            // Can emit only sources that are not declaration file and are either non module code or module with
+            // --module or --target es6 specified. Files included by searching under node_modules are also not emitted.
+            const nodeModulesFiles = host.getFilesFromNodeModules();
             const bundledSources = filter(host.getSourceFiles(),
-                sourceFile => !isDeclarationFile(sourceFile) &&    // Not a declaration file
-                              (!isExternalModule(sourceFile) ||    // non module file
-                               !!getEmitModuleKind(options)));     // module that can emit - note falsy value from getEmitModuleKind means the module kind that shouldn't be emitted
+                sourceFile => !isDeclarationFile(sourceFile) &&
+                              !lookUp(nodeModulesFiles, sourceFile.path) &&
+                              (!isExternalModule(sourceFile) ||
+                               !!getEmitModuleKind(options)));
             if (bundledSources.length) {
                 const jsFilePath = options.outFile || options.out;
                 const emitFileNames: EmitFileNames = {