@typescript-runtime-schema/expect-transformer-to-transform-program

Expect a set of source files to be transformed to using the provided transformer

Installation

Using npm:

npm install @typescript-runtime-schema/expect-transformer-to-transform-program

Using yarn:

yarn add @typescript-runtime-schema/expect-transformer-to-transform-program

Setup

Import @typescript-runtime-schema/expect-transformer-to-transform-program at the top of your test file:

import '@typescript-runtime-schema/expect-transformer-to-transform-program'

Usage

.toTransformProgram

expect(transformer).toTransformProgram(inputFiles, outputFiles)

Use .toTransformProgram when checking if your typescript transformer can transform the given source files to expected code output

import '@typescript-runtime-schema/expect-transformer-to-transform-program'
// Used to ignore the identation of template string
import dedent from 'dedent'

const sourceFiles = {
  "./foo.ts": `import * as bar from './bar`,
  "./bar.ts": `export const bar = "foo"`
}

const expectedOutputFiles = {
  "./foo.js": dedent`
    "use strict";
    exports.__esModule = true;
    var baz = require("bar");
  `,
  "./baz.js": dedent`
    "use strict";
    exports.__esModule = true;
    exports.bar = void 0;
    exports.bar = "bar";
  `
}

// Reader exercise: Transformer implementation
expect(transformer).toTransformProgram(sourceFiles, expectedOutputFiles)

compilerOptions

expect-transformer-to-transform-program uses the following compilerOptions:

{
  "moduleResolution": "node",
  "module": "commonjs",
  "target": "es2020",
  "declaration": true
}

API

.toTransformProgram

expect(transformer).toTransformProgram(sourceFiles, expectedOutputFiles)

Parameters

Name	Type	Description
expect	(ts.Program) => (ts.TransformationContext) => (ts.SourceFile) => ts.SourceFile	The typescript compiler transformation function.
sourceFiles	Record<string, string>	The source files we're passing through the transformer keyed by the file name/path
expectedOutputFiles	Record<string, string>	Our expected output of the transformer keyed by file name/path

License

MIT License Copyright (c) 2021 Simon Johansson

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice (including the next paragraph) shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.