fix(ivy): don't use a custom ts.CompilerHost for ngtsc (#25080)

ngtsc used to have a custom ts.CompilerHost which delegated to the plain
ts.CompilerHost. There's no need for this wrapper class and it causes
issues with CLI integration, so delete it.

PR Close #25080

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

@@ -1,77 +0,0 @@
-/**
- * @license
- * Copyright Google Inc. All Rights Reserved.
- *
- * Use of this source code is governed by an MIT-style license that can be
- * found in the LICENSE file at https://angular.io/license
- */
-
-import * as ts from 'typescript';
-
-/**
- * The TypeScript compiler host used by `ngtsc`.
- *
- * It's mostly identical to the native `CompilerHost`, but also includes the ability to
- * asynchronously resolve resources.
- */
-export interface CompilerHost extends ts.CompilerHost {
-  /**
-   * Begin processing a resource file.
-   *
-   * When the returned Promise resolves, `loadResource` should be able to synchronously produce a
-   * `string` for the given file.
-   */
-  preloadResource(file: string): Promise<void>;
-
-  /**
-   * Like `readFile`, but reads the contents of a resource file which may have been pre-processed
-   * by `preloadResource`.
-   */
-  loadResource(file: string): string|undefined;
-}
-
-/**
- * Implementation of `CompilerHost` which delegates to a native TypeScript host in most cases.
- */
-export class NgtscCompilerHost implements CompilerHost {
-  constructor(private delegate: ts.CompilerHost) {}
-
-  getSourceFile(
-      fileName: string, languageVersion: ts.ScriptTarget,
-      onError?: ((message: string) => void)|undefined,
-      shouldCreateNewSourceFile?: boolean|undefined): ts.SourceFile|undefined {
-    return this.delegate.getSourceFile(
-        fileName, languageVersion, onError, shouldCreateNewSourceFile);
-  }
-
-  getDefaultLibFileName(options: ts.CompilerOptions): string {
-    return this.delegate.getDefaultLibFileName(options);
-  }
-
-  writeFile(
-      fileName: string, data: string, writeByteOrderMark: boolean,
-      onError: ((message: string) => void)|undefined,
-      sourceFiles: ReadonlyArray<ts.SourceFile>): void {
-    return this.delegate.writeFile(fileName, data, writeByteOrderMark, onError, sourceFiles);
-  }
-
-  getCurrentDirectory(): string { return this.delegate.getCurrentDirectory(); }
-
-  getDirectories(path: string): string[] { return this.delegate.getDirectories(path); }
-
-  getCanonicalFileName(fileName: string): string {
-    return this.delegate.getCanonicalFileName(fileName);
-  }
-
-  useCaseSensitiveFileNames(): boolean { return this.delegate.useCaseSensitiveFileNames(); }
-
-  getNewLine(): string { return this.delegate.getNewLine(); }
-
-  fileExists(fileName: string): boolean { return this.delegate.fileExists(fileName); }
-
-  readFile(fileName: string): string|undefined { return this.delegate.readFile(fileName); }
-
-  loadResource(file: string): string|undefined { throw new Error('Method not implemented.'); }
-
-  preloadResource(file: string): Promise<void> { throw new Error('Method not implemented.'); }
-}

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

@@ -13,7 +13,6 @@ import * as ts from 'typescript';
 import * as api from '../transformers/api';
 
 import {ComponentDecoratorHandler, DirectiveDecoratorHandler, InjectableDecoratorHandler, NgModuleDecoratorHandler, PipeDecoratorHandler, ResourceLoader, SelectorScopeRegistry} from './annotations';
-import {CompilerHost} from './compiler_host';
 import {TypeScriptReflectionHost} from './metadata';
 import {FileResourceLoader, HostResourceLoader} from './resource_loader';
 import {IvyCompilation, ivyTransformFactory} from './transform';

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

@@ -12,7 +12,6 @@ import * as ts from 'typescript';
 
 import {TypeCheckHost} from '../diagnostics/translate_diagnostics';
 import {METADATA_VERSION, ModuleMetadata} from '../metadata/index';
-import {NgtscCompilerHost} from '../ngtsc/compiler_host';
 
 import {CompilerHost, CompilerOptions, LibrarySummary} from './api';
 import {MetadataReaderHost, createMetadataReaderCache, readMetadata} from './metadata_reader';
@@ -24,9 +23,6 @@ const EXT = /(\.ts|\.d\.ts|\.js|\.jsx|\.tsx)$/;
 export function createCompilerHost(
     {options, tsHost = ts.createCompilerHost(options, true)}:
         {options: CompilerOptions, tsHost?: ts.CompilerHost}): CompilerHost {
-  if (options.enableIvy === 'ngtsc' || options.enableIvy === 'tsc') {
-    return new NgtscCompilerHost(tsHost);
-  }
   return tsHost;
 }