angular/angular-cli · error · Error

Build target is not defined for this project.

Error message

Build target is not defined for this project.

What it means

When adding a web worker, the schematic wires a webWorkerTsConfig option into the project's "build" target. If the project has no "build" target defined, this Error is thrown since the tsconfig cannot be attached anywhere meaningful.

Solutions

1. Add a "build" target to the project in angular.json configured with @angular/build:application (or build-angular:application/browser).
2. Ensure the target is named "build" — if you renamed it (e.g. to "compile"), rename it back or add an alias target.
3. After the build target exists, rerun `ng g web-worker <name> --project=<project>` so the worker tsconfig gets wired in.

Example fix

// before (angular.json project)
"architect": { "test": { ... } }
// after
"architect": { "build": { "builder": "@angular/build:application", "options": { ... } }, "test": { ... } }

const ws = JSON.parse(fs.readFileSync('angular.json', 'utf8'));
const p = ws.projects?.[name];
if (!p?.architect?.build && !p?.targets?.build) {
  throw new Error(`Project "${name}" has no "build" target; add @angular/build:application first.`);
}

try {
  await ngGenerate(['web-worker', workerName, '--project', name]);
} catch (e) {
  if (String((e as Error).message).includes('Build target is not defined')) {
    console.error(`Add a "build" target for "${name}" in angular.json, then retry.`);
  } else throw e;
}

When it happens

Trigger: Running `ng generate web-worker` on a project (after the project lookup succeeds) whose angular.json targets/architect section lacks a "build" target — e.g. custom projects, test-only projects, or heavily restructured workspaces.

Common situations: Projects assembled manually without the standard application builder targets, monorepo setups where the build target was renamed, or projects migrated where the architect section was trimmed.

Related errors

• Cannot find 'options' for
• Could not find (/.angular.json)
• Invalid project name
• outputPath for target is not a string.
• Project name " " doesn't not exist.

AI-assisted analysis of angular/angular-cli@bb72145f9a (2026-08-30). Data as JSON: /api/errors/76278ffb599fe175. Report an issue: GitHub.

Appendix: source

Thrown at packages/schematics/angular/web-worker/index.ts:113

    const root = project.root || '';
    const templateSourceWorkerConfig = apply(url('./files/worker-tsconfig'), [
      applyTemplates({
        ...options,
        relativePathToWorkspaceRoot: relativePathToWorkspaceRoot(root),
      }),
      move(root),
    ]);

    return chain([
      // Add project configuration.
      updateWorkspace((workspace) => {
        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
        const project = workspace.projects.get(options.project)!;
        const buildTarget = project.targets.get('build');
        const testTarget = project.targets.get('test');
        if (!buildTarget) {
          throw new Error(`Build target is not defined for this project.`);
        }

        const workerConfigPath = join(root, 'tsconfig.worker.json');
        (buildTarget.options ??= {}).webWorkerTsConfig ??= workerConfigPath;
        if (testTarget) {
          (testTarget.options ??= {}).webWorkerTsConfig ??= workerConfigPath;
        }
      }),
      // Create the worker in a sibling module.
      options.snippet ? addSnippet(options) : noop(),
      // Add the worker.
      mergeWith(templateSourceWorkerCode),
      mergeWith(templateSourceWorkerConfig),
    ]);
  },
);

export default webWorkerSchematic;

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