angular-cn/packages/language-service/src/ts_plugin.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 * as ts from 'typescript'; // used as value, passed in by tsserver at runtime
import * as tss from 'typescript/lib/tsserverlibrary'; // used as type only

import {createLanguageService} from './language_service';
import {Completion, Diagnostic, DiagnosticMessageChain} from './types';
import {TypeScriptServiceHost} from './typescript_host';

const projectHostMap = new WeakMap<tss.server.Project, TypeScriptServiceHost>();

export function getExternalFiles(project: tss.server.Project): string[]|undefined {
  const host = projectHostMap.get(project);
  if (host) {
    const externalFiles = host.getTemplateReferences();
    return externalFiles;
  }
}

function completionToEntry(c: Completion): tss.CompletionEntry {
  return {
    // TODO: remove any and fix type error.
    kind: c.kind as any,
    name: c.name,
    sortText: c.sort,
    kindModifiers: ''
  };
}

function diagnosticChainToDiagnosticChain(chain: DiagnosticMessageChain):
    ts.DiagnosticMessageChain {
  return {
    messageText: chain.message,
    category: ts.DiagnosticCategory.Error,
    code: 0,
    next: chain.next ? diagnosticChainToDiagnosticChain(chain.next) : undefined
  };
}

function diagnosticMessageToDiagnosticMessageText(message: string | DiagnosticMessageChain): string|
    tss.DiagnosticMessageChain {
  if (typeof message === 'string') {
    return message;
  }
  return diagnosticChainToDiagnosticChain(message);
}

function diagnosticToDiagnostic(d: Diagnostic, file: tss.SourceFile | undefined): tss.Diagnostic {
  return {
    file,
    start: d.span.start,
    length: d.span.end - d.span.start,
    messageText: diagnosticMessageToDiagnosticMessageText(d.message),
    category: ts.DiagnosticCategory.Error,
    code: 0,
    source: 'ng'
  };
}

export function create(info: tss.server.PluginCreateInfo): tss.LanguageService {
  const {project, languageService: tsLS, languageServiceHost: tsLSHost, config} = info;
  // This plugin could operate under two different modes:
  // 1. TS + Angular
  //    Plugin augments TS language service to provide additional Angular
  //    information. This only works with inline templates and is meant to be
  //    used as a local plugin (configured via tsconfig.json)
  // 2. Angular only
  //    Plugin only provides information on Angular templates, no TS info at all.
  //    This effectively disables native TS features and is meant for internal
  //    use only.
  const angularOnly = config ? config.angularOnly === true : false;
  const ngLSHost = new TypeScriptServiceHost(tsLSHost, tsLS);
  const ngLS = createLanguageService(ngLSHost);
  projectHostMap.set(project, ngLSHost);

  function getCompletionsAtPosition(
      fileName: string, position: number,
      options: tss.GetCompletionsAtPositionOptions | undefined) {
    if (!angularOnly) {
      const results = tsLS.getCompletionsAtPosition(fileName, position, options);
      if (results && results.entries.length) {
        // If TS could answer the query, then return results immediately.
        return results;
      }
    }
    const results = ngLS.getCompletionsAt(fileName, position);
    if (!results || !results.length) {
      return;
    }
    return {
      isGlobalCompletion: false,
      isMemberCompletion: false,
      isNewIdentifierLocation: false,
      entries: results.map(completionToEntry),
    };
  }

  function getQuickInfoAtPosition(fileName: string, position: number): tss.QuickInfo|undefined {
    if (!angularOnly) {
      const result = tsLS.getQuickInfoAtPosition(fileName, position);
      if (result) {
        // If TS could answer the query, then return results immediately.
        return result;
      }
    }
    return ngLS.getHoverAt(fileName, position);
  }

  function getSemanticDiagnostics(fileName: string): tss.Diagnostic[] {
    const results: tss.Diagnostic[] = [];
    if (!angularOnly) {
      const tsResults = tsLS.getSemanticDiagnostics(fileName);
      results.push(...tsResults);
    }
    // For semantic diagnostics we need to combine both TS + Angular results
    const ngResults = ngLS.getDiagnostics(fileName);
    if (!ngResults.length) {
      return results;
    }
    const sourceFile = fileName.endsWith('.ts') ? ngLSHost.getSourceFile(fileName) : undefined;
    results.push(...ngResults.map(d => diagnosticToDiagnostic(d, sourceFile)));
    return results;
  }

  function getDefinitionAtPosition(
      fileName: string, position: number): ReadonlyArray<tss.DefinitionInfo>|undefined {
    if (!angularOnly) {
      const results = tsLS.getDefinitionAtPosition(fileName, position);
      if (results) {
        // If TS could answer the query, then return results immediately.
        return results;
      }
    }
    const result = ngLS.getDefinitionAt(fileName, position);
    if (!result || !result.definitions || !result.definitions.length) {
      return;
    }
    return result.definitions;
  }

  function getDefinitionAndBoundSpan(
      fileName: string, position: number): tss.DefinitionInfoAndBoundSpan|undefined {
    if (!angularOnly) {
      const result = tsLS.getDefinitionAndBoundSpan(fileName, position);
      if (result) {
        // If TS could answer the query, then return results immediately.
        return result;
      }
    }
    return ngLS.getDefinitionAt(fileName, position);
  }

  const proxy: tss.LanguageService = Object.assign(
      // First clone the original TS language service
      {}, tsLS,
      // Then override the methods supported by Angular language service
      {
          getCompletionsAtPosition, getQuickInfoAtPosition, getSemanticDiagnostics,
          getDefinitionAtPosition, getDefinitionAndBoundSpan,
      });
  return proxy;
}