angular/packages/language-service/ivy/language_service_adapter.ts
Keen Yee Liau 63624a2d46 feat(language-service): [Ivy] getSemanticDiagnostics for external templates (#39065)
This PR enables `getSemanticDiagnostics()` to be called on external templates.

Several changes are needed to land this feature:

1. The adapter needs to implement two additional methods:
   a. `readResource()`
       Load the template from snapshot instead of reading from disk
   b. `getModifiedResourceFiles()`
       Inform the compiler that external templates have changed so that the
       loader could invalidate its internal cache.
2. Create `ScriptInfo` for external templates in MockHost.
   Prior to this, MockHost only track changes in TypeScript files. Now it
   needs to create `ScriptInfo` for external templates as well.

For (1), in order to make sure we don't reload the template if it hasn't
changed, we need to keep track of its version. Since the complexity has
increased, the adapter is refactored into its own class.

PR Close #39065
2020-10-08 08:45:54 -07:00

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4.0 KiB
TypeScript

/**
* @license
* Copyright Google LLC 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 {NgCompilerAdapter} from '@angular/compiler-cli/src/ngtsc/core/api';
import {absoluteFrom, AbsoluteFsPath} from '@angular/compiler-cli/src/ngtsc/file_system';
import {isShim} from '@angular/compiler-cli/src/ngtsc/shims';
import * as ts from 'typescript/lib/tsserverlibrary';
export class LanguageServiceAdapter implements NgCompilerAdapter {
readonly entryPoint = null;
readonly constructionDiagnostics: ts.Diagnostic[] = [];
readonly ignoreForEmit: Set<ts.SourceFile> = new Set();
readonly factoryTracker = null; // no .ngfactory shims
readonly unifiedModulesHost = null; // only used in Bazel
readonly rootDirs: AbsoluteFsPath[];
private readonly templateVersion = new Map<string, string>();
private readonly modifiedTemplates = new Set<string>();
constructor(private readonly project: ts.server.Project) {
this.rootDirs = project.getCompilationSettings().rootDirs?.map(absoluteFrom) || [];
}
isShim(sf: ts.SourceFile): boolean {
return isShim(sf);
}
fileExists(fileName: string): boolean {
return this.project.fileExists(fileName);
}
readFile(fileName: string): string|undefined {
return this.project.readFile(fileName);
}
getCurrentDirectory(): string {
return this.project.getCurrentDirectory();
}
getCanonicalFileName(fileName: string): string {
return this.project.projectService.toCanonicalFileName(fileName);
}
/**
* readResource() is an Angular-specific method for reading files that are not
* managed by the TS compiler host, namely templates and stylesheets.
* It is a method on ExtendedTsCompilerHost, see
* packages/compiler-cli/src/ngtsc/core/api/src/interfaces.ts
*/
readResource(fileName: string): string {
if (isTypeScriptFile(fileName)) {
throw new Error(`readResource() should not be called on TS file: ${fileName}`);
}
// Calling getScriptSnapshot() will actually create a ScriptInfo if it does
// not exist! The same applies for getScriptVersion().
// getScriptInfo() will not create one if it does not exist.
// In this case, we *want* a script info to be created so that we could
// keep track of its version.
const snapshot = this.project.getScriptSnapshot(fileName);
if (!snapshot) {
// This would fail if the file does not exist, or readFile() fails for
// whatever reasons.
throw new Error(`Failed to get script snapshot while trying to read ${fileName}`);
}
const version = this.project.getScriptVersion(fileName);
this.templateVersion.set(fileName, version);
this.modifiedTemplates.delete(fileName);
return snapshot.getText(0, snapshot.getLength());
}
/**
* getModifiedResourceFiles() is an Angular-specific method for notifying
* the Angular compiler templates that have changed since it last read them.
* It is a method on ExtendedTsCompilerHost, see
* packages/compiler-cli/src/ngtsc/core/api/src/interfaces.ts
*/
getModifiedResourceFiles(): Set<string> {
return this.modifiedTemplates;
}
/**
* Check whether the specified `fileName` is newer than the last time it was
* read. If it is newer, register it and return true, otherwise do nothing and
* return false.
* @param fileName path to external template
*/
registerTemplateUpdate(fileName: string): boolean {
if (!isExternalTemplate(fileName)) {
return false;
}
const lastVersion = this.templateVersion.get(fileName);
const latestVersion = this.project.getScriptVersion(fileName);
if (lastVersion !== latestVersion) {
this.modifiedTemplates.add(fileName);
return true;
}
return false;
}
}
export function isTypeScriptFile(fileName: string): boolean {
return fileName.endsWith('.ts');
}
export function isExternalTemplate(fileName: string): boolean {
return !isTypeScriptFile(fileName);
}