refactor(compiler-cli): update emit signature to support for strongly typed emitCallback (#47893)

Currently `ngc-wrapped` mostly relies on any casts/or disabled
strictness checks to be able to use `tsickle`'s emit callback and
emit result merging for ngtsc. We should change this so that supertypes
of `ts.EmitResult` can be used in these optional callbacks- allowing us
to enable strictness checks in `packages/bazel/...` too.

PR Close #47893

packages/compiler-cli/src/main.ts

@@ -7,7 +7,7 @@
  */
 
 import ts from 'typescript';
-import type {TsickleHost} from 'tsickle';
+import type {TsickleHost, EmitResult as TsickleEmitResult} from 'tsickle';
 import yargs from 'yargs';
 import {exitCodeFromResult, formatDiagnostics, ParsedConfiguration, performCompilation, readConfiguration} from './perform_compile';
 import {createPerformWatchHost, performWatchCompilation} from './perform_watch';
@@ -91,8 +91,8 @@ export function mainDiagnosticsForTest(
   };
 }
 
-function createEmitCallback(
-    options: api.CompilerOptions, tsickle?: TsickleModule): api.TsEmitCallback|undefined {
+function createEmitCallback(options: api.CompilerOptions, tsickle?: TsickleModule):
+    api.TsEmitCallback<TsickleEmitResult>|undefined {
   if (!options.annotateForClosureCompiler) {
     return undefined;
   }

packages/compiler-cli/src/ngtsc/program.ts

@@ -231,14 +231,8 @@ export class NgtscProgram implements api.Program {
         this.options, ctx, resolve);
   }
 
-  emit(opts?: {
-    emitFlags?: api.EmitFlags|undefined;
-    forceEmit?: boolean;
-    cancellationToken?: ts.CancellationToken | undefined;
-    customTransformers?: api.CustomTransformers | undefined;
-    emitCallback?: api.TsEmitCallback | undefined;
-    mergeEmitResultsCallback?: api.TsMergeEmitResultsCallback | undefined;
-  }|undefined): ts.EmitResult {
+  emit<CbEmitRes extends ts.EmitResult>(opts?: api.EmitOptions<CbEmitRes>|
+                                        undefined): ts.EmitResult {
     // Check if emission of the i18n messages bundle was requested.
     if (opts !== undefined && opts.emitFlags !== undefined &&
         opts.emitFlags & api.EmitFlags.I18nBundle) {
@@ -263,7 +257,8 @@ export class NgtscProgram implements api.Program {
     const res = this.compiler.perfRecorder.inPhase(PerfPhase.TypeScriptEmit, () => {
       const {transformers} = this.compiler.prepareEmit();
       const ignoreFiles = this.compiler.ignoreForEmit;
-      const emitCallback = opts && opts.emitCallback || defaultEmitCallback;
+      const emitCallback =
+          (opts?.emitCallback ?? defaultEmitCallback) as api.TsEmitCallback<CbEmitRes>;
 
       const writeFile: ts.WriteFileCallback =
           (fileName: string, data: string, writeByteOrderMark: boolean,
@@ -291,7 +286,7 @@ export class NgtscProgram implements api.Program {
         beforeTransforms.push(...customTransforms.beforeTs);
       }
 
-      const emitResults: ts.EmitResult[] = [];
+      const emitResults: CbEmitRes[] = [];
 
       for (const targetSourceFile of this.tsProgram.getSourceFiles()) {
         if (targetSourceFile.isDeclarationFile || ignoreFiles.has(targetSourceFile)) {
@@ -345,7 +340,7 @@ export class NgtscProgram implements api.Program {
   }
 }
 
-const defaultEmitCallback: api.TsEmitCallback = ({
+const defaultEmitCallback: api.TsEmitCallback<ts.EmitResult> = ({
   program,
   targetSourceFile,
   writeFile,

packages/compiler-cli/src/perform_compile.ts

@@ -208,7 +208,7 @@ export function exitCodeFromResult(diags: ReadonlyArray<ts.Diagnostic>|undefined
   return diags.some(d => d.source === 'angular' && d.code === api.UNKNOWN_ERROR_CODE) ? 2 : 1;
 }
 
-export function performCompilation({
+export function performCompilation<CbEmitRes extends ts.EmitResult = ts.EmitResult>({
   rootNames,
   options,
   host,
@@ -225,8 +225,8 @@ export function performCompilation({
   options: api.CompilerOptions,
   host?: api.CompilerHost,
   oldProgram?: api.Program,
-  emitCallback?: api.TsEmitCallback,
-  mergeEmitResultsCallback?: api.TsMergeEmitResultsCallback,
+  emitCallback?: api.TsEmitCallback<CbEmitRes>,
+  mergeEmitResultsCallback?: api.TsMergeEmitResultsCallback<CbEmitRes>,
   gatherDiagnostics?: (program: api.Program) => ReadonlyArray<ts.Diagnostic>,
   customTransformers?: api.CustomTransformers,
   emitFlags?: api.EmitFlags,

packages/compiler-cli/src/perform_watch.ts

@@ -39,11 +39,11 @@ export enum FileChangeEvent {
   CreateDeleteDir,
 }
 
-export interface PerformWatchHost {
+export interface PerformWatchHost<CbEmitRes extends ts.EmitResult = ts.EmitResult> {
   reportDiagnostics(diagnostics: ReadonlyArray<ts.Diagnostic>): void;
   readConfiguration(): ParsedConfiguration;
   createCompilerHost(options: api.CompilerOptions): api.CompilerHost;
-  createEmitCallback(options: api.CompilerOptions): api.TsEmitCallback|undefined;
+  createEmitCallback(options: api.CompilerOptions): api.TsEmitCallback<CbEmitRes>|undefined;
   onFileChange(
       options: api.CompilerOptions, listener: (event: FileChangeEvent, fileName: string) => void,
       ready: () => void): {close: () => void};
@@ -51,11 +51,11 @@ export interface PerformWatchHost {
   clearTimeout(timeoutId: any): void;
 }
 
-export function createPerformWatchHost(
+export function createPerformWatchHost<CbEmitRes extends ts.EmitResult = ts.EmitResult>(
     configFileName: string, reportDiagnostics: (diagnostics: ReadonlyArray<ts.Diagnostic>) => void,
     existingOptions?: ts.CompilerOptions,
     createEmitCallback?: (options: api.CompilerOptions) =>
-        api.TsEmitCallback | undefined): PerformWatchHost {
+        api.TsEmitCallback<CbEmitRes>| undefined): PerformWatchHost {
   return {
     reportDiagnostics: reportDiagnostics,
     createCompilerHost: options => createCompilerHost({options}),

packages/compiler-cli/src/transformers/api.ts

@@ -162,11 +162,11 @@ export interface TsEmitArguments {
   customTransformers?: ts.CustomTransformers;
 }
 
-export interface TsEmitCallback {
-  (args: TsEmitArguments): ts.EmitResult;
+export interface TsEmitCallback<T extends ts.EmitResult> {
+  (args: TsEmitArguments): T;
 }
-export interface TsMergeEmitResultsCallback {
-  (results: ts.EmitResult[]): ts.EmitResult;
+export interface TsMergeEmitResultsCallback<T extends ts.EmitResult> {
+  (results: T[]): T;
 }
 
 export interface LazyRoute {
@@ -175,6 +175,15 @@ export interface LazyRoute {
   referencedModule: {name: string, filePath: string};
 }
 
+export interface EmitOptions<CbEmitRes extends ts.EmitResult> {
+  emitFlags?: EmitFlags;
+  forceEmit?: boolean;
+  cancellationToken?: ts.CancellationToken;
+  customTransformers?: CustomTransformers;
+  emitCallback?: TsEmitCallback<CbEmitRes>;
+  mergeEmitResultsCallback?: TsMergeEmitResultsCallback<CbEmitRes>;
+}
+
 export interface Program {
   /**
    * Retrieve the TypeScript program used to produce semantic diagnostics and emit the sources.
@@ -250,21 +259,7 @@ export interface Program {
    *
    * Angular structural information is required to emit files.
    */
-  emit({
-    emitFlags,
-    forceEmit,
-    cancellationToken,
-    customTransformers,
-    emitCallback,
-    mergeEmitResultsCallback,
-  }?: {
-    emitFlags?: EmitFlags,
-    forceEmit?: boolean,
-    cancellationToken?: ts.CancellationToken,
-    customTransformers?: CustomTransformers,
-    emitCallback?: TsEmitCallback,
-    mergeEmitResultsCallback?: TsMergeEmitResultsCallback
-  }): ts.EmitResult;
+  emit<CbEmitRes extends ts.EmitResult>(opts?: EmitOptions<CbEmitRes>|undefined): ts.EmitResult;
 
   /**
    * @internal