Skip typechecking file when generating declaraiton to get d.ts signat…

…ure for incremental build (#58592)

src/compiler/checker.ts

@@ -2428,10 +2428,10 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
  return visitEachChild(node, markAsSynthetic, /*context*/ undefined);
  }
 
- function getEmitResolver(sourceFile: SourceFile, cancellationToken: CancellationToken) {
+ function getEmitResolver(sourceFile: SourceFile, cancellationToken: CancellationToken, skipDiagnostics?: boolean) {
  // Ensure we have all the type information in place for this file so that all the
  // emitter questions of this resolver will return the right information.
- getDiagnostics(sourceFile, cancellationToken);
+ if (!skipDiagnostics) getDiagnostics(sourceFile, cancellationToken);
  return emitResolver;
  }
 

src/compiler/emitter.ts

@@ -717,6 +717,11 @@ export function getFirstProjectOutput(configFile: ParsedCommandLine, ignoreCase:
  return Debug.fail(`project ${configFile.options.configFilePath} expected to have at least one output`);
 }
 
+/** @internal */
+export function emitResolverSkipsTypeChecking(emitOnly: boolean | EmitOnly | undefined, forceDtsEmit: boolean | undefined) {
+ return !!forceDtsEmit && !!emitOnly;
+}
+
 /** @internal */
 // targetSourceFile is when users only want one file in entire project to be emitted. This is used in compileOnSave feature
 export function emitFiles(resolver: EmitResolver, host: EmitHost, targetSourceFile: SourceFile | undefined, { scriptTransformers, declarationTransformers }: EmitTransformers, emitOnly?: boolean | EmitOnly, onlyBuildInfo?: boolean, forceDtsEmit?: boolean): EmitResult {
@@ -848,7 +853,11 @@ export function emitFiles(resolver: EmitResolver, host: EmitHost, targetSourceFi
  const filesForEmit = forceDtsEmit ? sourceFiles : filter(sourceFiles, isSourceFileNotJson);
  // Setup and perform the transformation to retrieve declarations from the input files
  const inputListOrBundle = compilerOptions.outFile ? [factory.createBundle(filesForEmit)] : filesForEmit;
- if ((emitOnly && !getEmitDeclarations(compilerOptions)) || compilerOptions.noCheck) {
+ if (
+ (emitOnly && !getEmitDeclarations(compilerOptions)) ||
+ compilerOptions.noCheck ||
+ emitResolverSkipsTypeChecking(emitOnly, forceDtsEmit)
+ ) {
  // Checker wont collect the linked aliases since thats only done when declaration is enabled and checking is performed.
  // Do that here when emitting only dts files
  filesForEmit.forEach(collectLinkedAliases);

src/compiler/program.ts

@@ -68,6 +68,7 @@ import {
  EmitHost,
  emitModuleKindIsNonNodeESM,
  EmitOnly,
+ emitResolverSkipsTypeChecking,
  EmitResult,
  emptyArray,
  ensureTrailingDirectorySeparator,
@@ -2870,18 +2871,27 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
  // This is because in the -out scenario all files need to be emitted, and therefore all
  // files need to be type checked. And the way to specify that all files need to be type
  // checked is to not pass the file to getEmitResolver.
- const emitResolver = getTypeChecker().getEmitResolver(options.outFile ? undefined : sourceFile, cancellationToken);
+ const typeChecker = getTypeChecker();
+ const emitResolver = typeChecker.getEmitResolver(
+ options.outFile ? undefined : sourceFile,
+ cancellationToken,
+ emitResolverSkipsTypeChecking(emitOnly, forceDtsEmit),
+ );
 
  performance.mark("beforeEmit");
 
- const emitResult = emitFiles(
- emitResolver,
- getEmitHost(writeFileCallback),
- sourceFile,
- getTransformers(options, customTransformers, emitOnly),
- emitOnly,
- /*onlyBuildInfo*/ false,
- forceDtsEmit,
+ const emitResult = typeChecker.runWithCancellationToken(
+ cancellationToken,
+ () =>
+ emitFiles(
+ emitResolver,
+ getEmitHost(writeFileCallback),
+ sourceFile,
+ getTransformers(options, customTransformers, emitOnly),
+ emitOnly,
+ /*onlyBuildInfo*/ false,
+ forceDtsEmit,
+ ),
  );
 
  performance.mark("afterEmit");

src/compiler/types.ts

@@ -5264,7 +5264,7 @@ export interface TypeChecker {
  // Should not be called directly. Should only be accessed through the Program instance.
  /** @internal */ getDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
  /** @internal */ getGlobalDiagnostics(): Diagnostic[];
- /** @internal */ getEmitResolver(sourceFile?: SourceFile, cancellationToken?: CancellationToken): EmitResolver;
+ /** @internal */ getEmitResolver(sourceFile?: SourceFile, cancellationToken?: CancellationToken, forceDts?: boolean): EmitResolver;
 
  /** @internal */ getNodeCount(): number;
  /** @internal */ getIdentifierCount(): number;
@@ -5354,6 +5354,8 @@ export interface TypeChecker {
  * and the operation is cancelled, then it should be discarded, otherwise it is safe to keep.
  */
  runWithCancellationToken<T>(token: CancellationToken, cb: (checker: TypeChecker) => T): T;
+ /**@internal */
+ runWithCancellationToken<T>(token: CancellationToken | undefined, cb: (checker: TypeChecker) => T): T; // eslint-disable-line @typescript-eslint/unified-signatures
 
  /** @internal */ getLocalTypeParametersOfClassOrInterfaceOrTypeAlias(symbol: Symbol): readonly TypeParameter[] | undefined;
  /** @internal */ isDeclarationVisible(node: Declaration | AnyImportSyntax): boolean;

src/testRunner/unittests/tsc/cancellationToken.ts

@@ -17,7 +17,7 @@ import {
  libFile,
 } from "../helpers/virtualFileSystemWithWatch.js";
 
-describe("unittests:: tsc:: builder cancellationToken", () => {
+describe("unittests:: tsc:: builder cancellationToken::", () => {
  verifyCancellation(/*useBuildInfo*/ true, "when emitting buildInfo");
  verifyCancellation(/*useBuildInfo*/ false, "when using state");
  function verifyCancellation(useBuildInfo: boolean, scenario: string) {
@@ -41,9 +41,9 @@ describe("unittests:: tsc:: builder cancellationToken", () => {
  const cFile: File = {
  path: `/user/username/projects/myproject/c.ts`,
  content: Utils.dedent`
- export class C {
+ export var C = class CReal {
  d = 1;
- }`,
+ };`,
  };
  const dFile: File = {
  path: `/user/username/projects/myproject/d.ts`,