Registry / testing / lab-transform-typescript

lab-transform-typescript

library3.0.1jsnpmunverified

lab-transform-typescript is a utility that enables the `lab` testing framework to directly execute TypeScript test files without requiring a separate pre-compilation step. This allows for a more streamlined `npm test` workflow for projects using TypeScript with `lab`. The current stable version is 3.0.1, which includes inlined source maps for better error reporting. The package's release cadence is not fixed, typically driven by updates to the `lab` framework or `typescript` itself. Key differentiators include its tight integration with `lab`, support for source maps, and the provision of optional type definitions for `lab` and `code` (the assertion library used with `lab`), enhancing the development experience for TypeScript users within the `lab` ecosystem. It leverages TypeScript's official configuration loader and parser since version 3.0.0.

testing

npm install lab-transform-typescript

github ↗package ↗

INSTALL

IMPORT

SIG · LAB-TRANSFORM-TYPE

lab-transform-typescript

testingjavascriptv3.0.1

Install

—

Import

—

Disk

—

Pass rate

0/ 6

Env Coverage0 / 6

glibc

18–22

musl

18–22

Install & Compatibility

Where this runs

tested against v? · npm install

Install × environment matrix

Each cell = how many times install + import succeeded across repeated harness runs. Partial = flaky.
glibc = Debian/Ubuntu slim · musl = Alpine Linux

musl

node 18–226 runs

build_error

glibc

node 18–226 runs

build_error

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

transformFunction

✓ const transform = require('lab-transform-typescript');

✗ import transform from 'lab-transform-typescript';

The package's main export is a CommonJS function, directly assignable to a variable. While Node.js ESM can often import CJS defaults, explicit `require` is the guaranteed correct way for direct programmatic usage in CJS environments.

LabCLIUsage

✓ /* No JS import; used via CLI: */ lab --sourcemaps --transform node_modules/lab-transform-typescript

The primary and most common way developers 'use' this package is by configuring the `lab` CLI to apply it as a transform, not by importing its symbols into userland JavaScript/TypeScript code.

TypeScriptTypes

✓ /* No direct JS import for these types; they are installed separately */

✗ import { LabTypings } from 'lab-transform-typescript/typings-local/lab.d.ts'

While `lab-transform-typescript` provides typings for `lab` and `code`, these are installed via `typings install` from specific GitHub paths and are not directly imported from the `lab-transform-typescript` npm package itself. This entry highlights the *availability* of these types, not a direct programmatic import from this package.

Demonstrates installation and configuration of `lab-transform-typescript` to enable direct execution of TypeScript test files using the `lab` CLI.

npm install --save-dev lab-transform-typescript typescript // In a TypeScript test file (e.g., test/example.test.ts): // import { expect } from '@hapi/code'; // import { describe, it } from '@hapi/lab'; // describe('My Test Suite', () => { // it('should pass', () => { // expect(1 + 1).to.equal(2); // }); // }); // To run tests, execute in your terminal: // (Ensure 'lab' is installed globally or in node_modules/.bin) process.env.TSCONFIG = process.env.TSCONFIG ?? './tsconfig.json'; // Optional: specify tsconfig path console.log(`Running tests with lab transform and TSCONFIG: ${process.env.TSCONFIG}`); // Execute this command via package.json 'test' script or directly if lab is global: // lab --sourcemaps --transform node_modules/lab-transform-typescript --verbose // To make it runnable in a script: // const { spawn } = require('child_process'); // const lab = spawn('npx', [ // 'lab', // '--sourcemaps', // '--transform', // 'node_modules/lab-transform-typescript', // '--verbose', // 'test/**/*.ts' // Example glob for test files // ], { stdio: 'inherit' }); // lab.on('close', (code) => process.exit(code));

Debug

Known issues

breakingVersion 3.0.0 switched to TypeScript's official configuration loader and parser. This might affect how `tsconfig.json` files are resolved and parsed, especially in complex project setups.

fix

Review your `tsconfig.json` and ensure it's compatible with TypeScript's standard parsing. The `TSCONFIG` environment variable can be used to explicitly override the `tsconfig.json` location.

affects: >=3.0.0

breakingVersion 2.0.0 moved `typescript` from `dependencies` to `peerDependencies`. This means `typescript` is no longer automatically installed by `lab-transform-typescript` and must be explicitly installed by the consuming project.

fix

Ensure `typescript` is installed as a `devDependency` in your project (`npm install typescript --save-dev`). The version of `typescript` used will be the one from your project's `node_modules`.

affects: >=2.0.0

gotchaWhen using `lab --coverage` with `lab-transform-typescript`, the coverage report may display transpiled JavaScript code instead of the original TypeScript source, making it harder to interpret results in terms of the original source.

fix

There is no direct fix for this known issue (#1 in the project's issue tracker, linked to `hapijs/lab#614`). It's a limitation of how `lab` processes transformed output for coverage.

affects: >=1.0.0

gotchaThe version of `typescript` used by the transform depends on how `lab-transform-typescript` itself is installed. If linked via `npm link`, it uses its own `node_modules` `typescript` version; otherwise, it uses the `typescript` from the project's `node_modules`.

fix

For consistent behavior, install `lab-transform-typescript` directly via `npm install --save-dev` rather than `npm link` in production or shared development environments, ensuring `typescript` is a direct `devDependency` of your project.

affects: >=1.0.0

Errors

Common errors & fixes

Error: Cannot find module 'typescript' from 'node_modules/lab-transform-typescript'

`typescript` is a peer dependency and was not installed in the consuming project.

fix

`npm install typescript --save-dev` to add `typescript` to your project's development dependencies.

SyntaxError: Unexpected token 'import' (or 'export') when running tests.

This typically occurs if `lab` is trying to run a TypeScript file directly without the transform, or if the transform is misconfigured.

fix

Ensure `lab --transform node_modules/lab-transform-typescript` is correctly specified in your test command and that the path to the transform is accurate. Also, ensure `lab` itself is configured to process the correct file extensions (e.g., `.ts`).

TSCONFIG environment variable ignored or tsconfig.json not found.

The `TSCONFIG` environment variable might be incorrectly set, or TypeScript's default `tsconfig.json` search (which the transform uses since v3.0.0) isn't finding the desired file.

fix

Double-check the path provided to `TSCONFIG`. Ensure the `tsconfig.json` file exists at the specified path or in a location where TypeScript's default search mechanism would find it (e.g., project root). Ensure you are on `lab-transform-typescript` v3 or newer for this feature.

Upgrade

Version history

3.0.1latest on npm

Audit

Dependencies

typescriptrequiredRequired for transforming TypeScript code. Moved to peerDependencies in v2.0.0.

Agent activity

4 hits · last 30 days

node

Resources

githubhttps://github.com/garthk/lab-transform-typescript ↗

packagehttps://www.npmjs.com/package/lab-transform-typescript ↗