Function parseNgCompilerOptions

packages/language-service/src/language_service.ts:949–998

(
  project: ts.server.Project,
  host: ConfigurationHost,
  config: LanguageServiceConfig,
)

}

function parseNgCompilerOptions(
  project: ts.server.Project,
  host: ConfigurationHost,
  config: LanguageServiceConfig,
): CompilerOptions {
  if (!(project instanceof ts.server.ConfiguredProject)) {
    return {};
  }
  const {options, errors} = readConfiguration(
    project.getConfigFilePath(),
    /* existingOptions */ undefined,
    host,
  );
  if (errors.length > 0) {
    project.setProjectErrors(errors);
  }

  // Projects loaded into the Language Service often include test files which are not part of the
  // app's main compilation unit, and these test files often include inline NgModules that declare
  // components from the app. These declarations conflict with the main declarations of such
  // components in the app's NgModules. This conflict is not normally present during regular
  // compilation because the app and the tests are part of separate compilation units.
  //
  // As a temporary mitigation of this problem, we instruct the compiler to ignore classes which
  // are not exported. In many cases, this ensures the test NgModules are ignored by the compiler
  // and only the real component declaration is used.
  options.compileNonExportedClasses = false;

  // If `forceStrictTemplates` is true, always enable `strictTemplates`
  // regardless of its value in tsconfig.json.
  if (config['forceStrictTemplates'] === true) {
    options.strictTemplates = true;
  }
  if (config['enableSelectorless'] === true) {
    options['_enableSelectorless'] = true;
  }

  options['_angularCoreVersion'] = config['angularCoreVersion'];

  if (project.getCurrentDirectory()) {
    // Attempt to resolve the version of @angular/core that is installed in the project.
    // This is useful for monorepos where different projects may use different versions of Angular.
    const detectedVersion = detectAngularCoreVersion(project, host);
    if (detectedVersion !== null) {
      options['_angularCoreVersion'] = detectedVersion;
    }
  }

  return options;
}

function detectAngularCoreVersion(
  project: ts.server.ConfiguredProject,