angular/angular-cli · error · Error

Project name must be a valid npm package name.

Error message

Project name must be a valid npm package name.

What it means

ProjectDefinitionCollection._validateName enforces npm package naming rules with the regex /^(?:@\w[\w.-]*\/)?\w[\w.-]*$/. Names must be a string, optionally scoped (@scope/), start with a word character, and contain only word characters, dots, and hyphens. Anything else throws this Error.

Source

Thrown at packages/angular_devkit/core/src/workspace/definitions.ts:203

      }
    }

    super.set(definition.name, project);

    return project;
  }

  override set(name: string, value: ProjectDefinition): this {
    this._validateName(name);

    super.set(name, value);

    return this;
  }

  private _validateName(name: string): void {
    if (typeof name !== 'string' || !/^(?:@\w[\w.-]*\/)?\w[\w.-]*$/.test(name)) {
      throw new Error('Project name must be a valid npm package name.');
    }
  }
}

export class TargetDefinitionCollection extends DefinitionCollection<TargetDefinition> {
  constructor(
    initial?: Record<string, TargetDefinition>,
    listener?: DefinitionCollectionListener<TargetDefinition>,
  ) {
    super(initial, listener);
  }

  add(
    definition: {
      name: string;
    } & TargetDefinition,
  ): TargetDefinition {
    if (this.has(definition.name)) {

View on GitHub (pinned to bb72145f9a)

Solutions

1. Rename the project to a valid npm-style name: lowercase-ish word chars, dots or hyphens, optional @scope/ prefix.
2. Sanitize derived names: replace invalid characters with '-' before calling add.
3. Validate with the same regex before calling: /^(?:@\w[\w.-]*\/)?\w[\w.-]*$/.test(name).

Example fix

// before
workspace.addProject({ name: 'my app', root: 'apps/my-app' });
// after
workspace.addProject({ name: 'my-app', root: 'apps/my-app' });

const NAME_RE = /^(?:@\w[\w.-]*\/)?\w[\w.-]*$/;
if (typeof name !== 'string' || !NAME_RE.test(name)) {
  throw new Error(`Invalid project name: ${JSON.stringify(name)}`);
}
workspace.addProject({ name, root });

function isValidProjectName(name: unknown): name is string {
  return typeof name === 'string' && /^(?:@\w[\w.-]*\/)?\w[\w.-]*$/.test(name);
}

try {
  project = workspace.addProject({ name, root });
} catch (e) {
  if (/valid npm package name/.test(e.message)) {
    const safe = name.replace(/[^\w.-]/g, '-').replace(/^[^\w]/, 'a');
    project = workspace.addProject({ name: safe, root });
  } else throw e;
}

When it happens

Trigger: addProject({ name }) or project collection set() with a name like 'my app', '1app', 'app/', 'app_name' (underscore is allowed by \w actually — but e.g. 'app!' is not), an empty string, or a scoped name with uppercase/invalid scope like '@Foo/bar'.

Common situations: Deriving project names from folder paths containing spaces or special chars; empty names from CLI prompts left blank; names with underscores or non-ASCII characters; scope names with capitals.

Related errors

• Project name already exists.
• "${name}" must be a JSON value.
• Target name already exists.
• Target name must be a string.
• Unable to read workspace file.

AI-assisted analysis of angular/angular-cli@bb72145f9a (2026-08-30). Data as JSON: /api/errors/a482ba6340717db3. Report an issue: GitHub.