Function tcb

packages/compiler-cli/src/ngtsc/typecheck/testing/index.ts:359–477

(
  template: string,
  declarations: TestDeclaration[] = [],
  config?: Partial<TypeCheckingConfig>,
  options?: {emitSpans?: boolean},
  templateParserOptions?: ParseTemplateOptions,
)

export type TestDeclaration = TestDirective | TestPipe;

export function tcb(
  template: string,
  declarations: TestDeclaration[] = [],
  config?: Partial<TypeCheckingConfig>,
  options?: {emitSpans?: boolean},
  templateParserOptions?: ParseTemplateOptions,
): string {
  const codeLines = [
    'declare const ɵNgFieldDirective: unique symbol;',
    `export class Test<T extends string> {}`,
  ];

  (function addCodeLines(currentDeclarations) {
    for (const decl of currentDeclarations) {
      if (decl.type === 'directive' && decl.hostDirectives) {
        addCodeLines(decl.hostDirectives.map((hostDir) => hostDir.directive));
      }

      codeLines.push(
        decl.code ??
          `export class ${decl.name}${decl.type === 'directive' || decl.isGeneric ? '<T extends string>' : ''} { ${
            (decl as TestDirective).hasNgFieldDirective === true ? '[ɵNgFieldDirective]: any;' : ''
          } }`,
      );
    }
  })(declarations);

  const rootFilePath = absoluteFrom('/synthetic.ts');
  const {program, host} = makeProgram([
    {name: rootFilePath, contents: codeLines.join('\n'), isRoot: true},
  ]);

  const sf = getSourceFileOrError(program, rootFilePath);
  const clazz = getClass(sf, 'Test');
  const templateUrl = 'synthetic.html';
  const {nodes, errors} = parseTemplate(template, templateUrl, templateParserOptions);
  const selectorlessEnabled = templateParserOptions?.enableSelectorless ?? false;

  if (errors !== null) {
    throw new Error('Template parse errors: \n' + errors.join('\n'));
  }

  const {matcher, pipes} = prepareDeclarations(
    declarations,
    (decl) => getClass(sf, decl.name),
    new Map(),
    selectorlessEnabled,
  );
  const binder = new R3TargetBinder<DirectiveMeta>(matcher);
  const boundTarget = binder.bind({template: nodes});

  const id = 'tcb' as TypeCheckId;
  const meta: TypeCheckBlockMetadata = {
    id,
    boundTarget,
    pipes,
    schemas: [],
    isStandalone: false,