From a32914f6872b9c5764d77f77ea85c7160ff9ae28 Mon Sep 17 00:00:00 2001
From: Andy Hanson <anhans@microsoft.com>
Date: Mon, 23 Jan 2017 11:14:29 -0800
Subject: [PATCH] Combine `forEachExpectedEmitFile` and `forEachEmittedFile`

---
 src/compiler/declarationEmitter.ts |  4 ++--
 src/compiler/emitter.ts            |  2 +-
 src/compiler/program.ts            |  2 +-
 src/compiler/utilities.ts          | 24 ++++++++----------------
 4 files changed, 12 insertions(+), 20 deletions(-)

diff --git a/src/compiler/declarationEmitter.ts b/src/compiler/declarationEmitter.ts
index 2287de179e3..46df4fed689 100644
--- a/src/compiler/declarationEmitter.ts
+++ b/src/compiler/declarationEmitter.ts
@@ -32,7 +32,7 @@ namespace ts {
 
     export function getDeclarationDiagnostics(host: EmitHost, resolver: EmitResolver, targetSourceFile: SourceFile): Diagnostic[] {
         const declarationDiagnostics = createDiagnosticCollection();
-        forEachExpectedEmitFile(host, getDeclarationDiagnosticsFromFile, targetSourceFile);
+        forEachEmittedFile(host, getDeclarationDiagnosticsFromFile, targetSourceFile);
         return declarationDiagnostics.getDiagnostics(targetSourceFile ? targetSourceFile.fileName : undefined);
 
         function getDeclarationDiagnosticsFromFile({ declarationFilePath }: EmitFileNames, sources: SourceFile[], isBundledEmit: boolean) {
@@ -1788,7 +1788,7 @@ namespace ts {
             }
             else {
                 // Get the declaration file path
-                forEachExpectedEmitFile(host, getDeclFileName, referencedFile, emitOnlyDtsFiles);
+                forEachEmittedFile(host, getDeclFileName, referencedFile, emitOnlyDtsFiles);
             }
 
             if (declFileName) {
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
index 1c4662fa587..cc006a06637 100644
--- a/src/compiler/emitter.ts
+++ b/src/compiler/emitter.ts
@@ -73,7 +73,7 @@ namespace ts {
 
         // Emit each output file
         performance.mark("beforePrint");
-        forEachEmittedFile(host, transformed, emitFile, emitOnlyDtsFiles);
+        forEachEmittedFile(host, emitFile, transformed, emitOnlyDtsFiles);
         performance.measure("printTime", "beforePrint");
 
         // Clean up emit nodes on parse tree
diff --git a/src/compiler/program.ts b/src/compiler/program.ts
index 851e206d448..650711afc79 100644
--- a/src/compiler/program.ts
+++ b/src/compiler/program.ts
@@ -1707,7 +1707,7 @@ namespace ts {
             if (!options.noEmit && !options.suppressOutputPathCheck) {
                 const emitHost = getEmitHost();
                 const emitFilesSeen = createFileMap<boolean>(!host.useCaseSensitiveFileNames() ? key => key.toLocaleLowerCase() : undefined);
-                forEachExpectedEmitFile(emitHost, (emitFileNames) => {
+                forEachEmittedFile(emitHost, (emitFileNames) => {
                     verifyEmitFilePath(emitFileNames.jsFilePath, emitFilesSeen);
                     verifyEmitFilePath(emitFileNames.declarationFilePath, emitFilesSeen);
                 });
diff --git a/src/compiler/utilities.ts b/src/compiler/utilities.ts
index f59d384e490..b7cc0f0de6d 100644
--- a/src/compiler/utilities.ts
+++ b/src/compiler/utilities.ts
@@ -2590,27 +2590,20 @@ namespace ts {
     }
 
     /**
-     * Iterates over the source files that are expected to have an emit output. This function
-     * is used by the legacy emitter and the declaration emitter and should not be used by
-     * the tree transforming emitter.
+     * Iterates over the source files that are expected to have an emit output.
      *
      * @param host An EmitHost.
      * @param action The action to execute.
-     * @param targetSourceFile An optional target source file to emit.
+     * @param sourceFilesOrTargetSourceFile
+     *   If an array, the full list of source files to emit.
+     *   Else, calls `getSourceFilesToEmit` with the (optional) target source file to determine the list of source files to emit.
      */
-    export function forEachExpectedEmitFile(host: EmitHost,
-        action: (emitFileNames: EmitFileNames, sourceFiles: SourceFile[], isBundledEmit: boolean, emitOnlyDtsFiles: boolean) => void,
-        targetSourceFile?: SourceFile,
+    export function forEachEmittedFile(
+        host: EmitHost, action: (emitFileNames: EmitFileNames, sourceFiles: SourceFile[], isBundledEmit: boolean, emitOnlyDtsFiles: boolean) => void,
+        sourceFilesOrTargetSourceFile?: SourceFile[] | SourceFile,
         emitOnlyDtsFiles?: boolean) {
-        forEachEmittedFile(host, getSourceFilesToEmit(host, targetSourceFile), action, emitOnlyDtsFiles);
-    }
 
-    /**
-     * Iterates over each source file to emit.
-     */
-    export function forEachEmittedFile(host: EmitHost, sourceFiles: SourceFile[],
-        action: (emitFileNames: EmitFileNames, sourceFiles: SourceFile[], isBundledEmit: boolean, emitOnlyDtsFiles: boolean) => void,
-        emitOnlyDtsFiles?: boolean) {
+        const sourceFiles = isArray(sourceFilesOrTargetSourceFile) ? sourceFilesOrTargetSourceFile : getSourceFilesToEmit(host, sourceFilesOrTargetSourceFile);
         const options = host.getCompilerOptions();
         if (options.outFile || options.out) {
             if (sourceFiles.length) {
@@ -2622,7 +2615,6 @@ namespace ts {
         }
         else {
             for (const sourceFile of sourceFiles) {
-                const options = host.getCompilerOptions();
                 const jsFilePath = getOwnEmitOutputFilePath(sourceFile, host, getOutputExtension(sourceFile, options));
                 const sourceMapFilePath = getSourceMapFilePath(jsFilePath, options);
                 const declarationFilePath = !isSourceFileJavaScript(sourceFile) && (emitOnlyDtsFiles || options.declaration) ? getDeclarationEmitOutputFilePath(sourceFile, host) : undefined;