ConfiguringTransformers.md

Configuring A Typescript Transformer

This page shows several ways to configure your project for use with ts-api-decorators-*, depending on what other frameworks you're using. Replace ts-api-decorators-* below with the name of the package you're using - e.g. ts-api-decorators-express.

ttypescript

The simplest way is to use ttypescript to compile instead of tsc directly.

Step 1: Install Dependencies First, install ttypescript as a dev dependency. Also be sure you have the correct tsapi package installed (e.g. ts-api-decorators-express).

npm i --save-dev ttypescript

Step 2: Update your tsconfig.json

// tsconfig.json
{
  "compilerOptions": {
    "plugins": [
      { "transform": "ts-api-decorators-*/transformer" }
    ]
  },
}

Step 3: Update your Build Script If you've been building your typescript by running tsc, then just replace tsc with ttypescript. The recommended way is to add a command in your package.json, like this:

// package.json
{
    "scripts": {
        "build": "ttypescript"
    }
}

Now you can build with npm run build.

Webpack

See examples/webpack for detail.

// webpack.config.js
const tsapiTransformer = require('ts-api-decorators-express/transformer').default;

module.exports = {
  // ...
  module: {
    rules: [
      {
        test: /\.ts$/,
        loader: 'ts-loader',
        options: {
          getCustomTransformers: program => ({
              before: [
                  tsapiTransformer(program)
              ]
          })
        }
      }
    ]
  }
};

TypeScript API

See test for detail. You can try it with $ npm test.

const ts = require('typescript');
const tsapiTransformer = require('ts-api-decorators-express/transformer').default;

const program = ts.createProgram([/* your files to compile */], {
    module: ts.ModuleKind.CommonJS,
    noEmitOnError: true,
    noImplicitAny: false,
    experimentalDecorators: true,
    target: ts.ScriptTarget.ES2019,
    downlevelIteration: true,
    sourceMap: true,
});

const transformers = {
    before: [tsapiTransformer(program)],
    after: []
};
const { emitSkipped, diagnostics } = program.emit(undefined, undefined, undefined, false, transformers);

if (emitSkipped) {
    throw new Error(diagnostics.map(diagnostic => diagnostic.messageText).join('\n'));
}