Installation

Forger consists of two parts: a runtime factory and a compile-time TypeScript transformer. The transformer is what makes Forger.create<T>() type-aware, so installing the package is only half of the story — the build pipeline has to apply the transformer as well.

Prerequisites

A supported TypeScript line: 5.x/6.x for Forger 2, 4.x for Forger 1 — see Versions for the full matrix.
A build that applies custom transformers: ts-jest, ts-patch, or the Angular plugin (see Integration).

1. Install the package

Install the line matching your TypeScript generation:

# TypeScript 5 or 6 — current line (branch v2)
npm install --save-dev @artstesh/forger

# TypeScript 4 — legacy line (branch v1)
npm install --save-dev @artstesh/forger@^1

Forger has no runtime dependencies, so nothing else lands in your dependency tree.

2. Install ts-patch

The transformer is applied through ts-patch, which teaches the TypeScript compiler to run transformers declared in tsconfig.json. ts-patch's major must match your TypeScript major:

# TypeScript 6+
npm install --save-dev ts-patch@^4

# TypeScript 5
npm install --save-dev ts-patch@^3

3. Declare the transformer in tsconfig.json

Add the transformer to the plugins section of the compiler options:

{
  "compilerOptions": {
    "plugins": [
      { "transform": "@artstesh/forger/lib/utils/transformer" }
    ]
  }
}

This single entry covers all build flavors that respect plugins: ts-patch CLI builds, ts-jest with the ts-patch compiler, and the Angular integration shipped with Forger.

4. Wire up your test runner

For Jest with ts-jest, point the compiler at ts-patch and register the transformer:

/** jest.config.js */
module.exports = {
  preset: 'ts-jest',
  transform: {
    '.*.spec.ts': ['ts-jest', {
      compiler: 'ts-patch/compiler',
      astTransformers: {
        before: ['@artstesh/forger/lib/utils/transformer']
      }
    }]
  }
};

Step-by-step instructions for every supported pipeline live in Integration with Jest, Integration with Angular, and Building with ts-patch.

5. Verify the setup

Create a spec and run the test suite:

import { Forger } from '@artstesh/forger';

it('forger is wired up', () => {
  const name = Forger.create<string>();
  //
  expect(typeof name).toBe('string');
});

If the test fails with name being undefined, the transformer is not applied — revisit step 3 and 4, and clear the Jest transform cache (jest --clearCache) after changing transformer configuration. Without the transformer, Forger.create<T>() always returns undefined (see Caveats).

Next steps

Continue with the Quick Start to forge your first object.

08 September 2026