angular-docs-cn/packages/language-service/src/language_service.ts

/**
 * @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 {CompilePipeSummary} from '@angular/compiler';
import * as tss from 'typescript/lib/tsserverlibrary';

import {getTemplateCompletions} from './completions';
import {getDefinitionAndBoundSpan} from './definitions';
import {getDeclarationDiagnostics, getTemplateDiagnostics, ngDiagnosticToTsDiagnostic} from './diagnostics';
import {getHover} from './hover';
import {Completion, Diagnostic, LanguageService, Span} from './types';
import {TypeScriptServiceHost} from './typescript_host';


/**
 * Create an instance of an Angular `LanguageService`.
 *
 * @publicApi
 */
export function createLanguageService(host: TypeScriptServiceHost): LanguageService {
  return new LanguageServiceImpl(host);
}

class LanguageServiceImpl implements LanguageService {
  constructor(private readonly host: TypeScriptServiceHost) {}

  getTemplateReferences(): string[] {
    this.host.getAnalyzedModules();  // same role as 'synchronizeHostData'
    return this.host.getTemplateReferences();
  }

  getDiagnostics(fileName: string): tss.Diagnostic[] {
    const analyzedModules = this.host.getAnalyzedModules();  // same role as 'synchronizeHostData'
    const results: Diagnostic[] = [];
    const templates = this.host.getTemplates(fileName);
    for (const template of templates) {
      const ast = this.host.getTemplateAst(template, fileName);
      results.push(...getTemplateDiagnostics(template, ast));
    }
    const declarations = this.host.getDeclarations(fileName);
    if (declarations && declarations.length) {
      results.push(...getDeclarationDiagnostics(declarations, analyzedModules));
    }
    if (!results.length) {
      return [];
    }
    const sourceFile = fileName.endsWith('.ts') ? this.host.getSourceFile(fileName) : undefined;
    return uniqueBySpan(results).map(d => ngDiagnosticToTsDiagnostic(d, sourceFile));
  }

  getPipesAt(fileName: string, position: number): CompilePipeSummary[] {
    this.host.getAnalyzedModules();  // same role as 'synchronizeHostData'
    const templateInfo = this.host.getTemplateAstAtPosition(fileName, position);
    if (templateInfo) {
      return templateInfo.pipes;
    }
    return [];
  }

  getCompletionsAt(fileName: string, position: number): Completion[]|undefined {
    this.host.getAnalyzedModules();  // same role as 'synchronizeHostData'
    const templateInfo = this.host.getTemplateAstAtPosition(fileName, position);
    if (templateInfo) {
      return getTemplateCompletions(templateInfo);
    }
  }

  getDefinitionAt(fileName: string, position: number): tss.DefinitionInfoAndBoundSpan|undefined {
    this.host.getAnalyzedModules();  // same role as 'synchronizeHostData'
    const templateInfo = this.host.getTemplateAstAtPosition(fileName, position);
    if (templateInfo) {
      return getDefinitionAndBoundSpan(templateInfo);
    }
  }

  getHoverAt(fileName: string, position: number): tss.QuickInfo|undefined {
    this.host.getAnalyzedModules();  // same role as 'synchronizeHostData'
    const templateInfo = this.host.getTemplateAstAtPosition(fileName, position);
    if (templateInfo) {
      return getHover(templateInfo);
    }
  }
}

function uniqueBySpan<T extends{span: Span}>(elements: T[]): T[] {
  const result: T[] = [];
  const map = new Map<number, Set<number>>();
  for (const element of elements) {
    const {span} = element;
    let set = map.get(span.start);
    if (!set) {
      set = new Set();
      map.set(span.start, set);
    }
    if (!set.has(span.end)) {
      set.add(span.end);
      result.push(element);
    }
  }
  return result;
}