Mrm TypeScript Task

Common errors

• command not found: mrm

  cause The Mrm command-line interface tool is not installed globally or accessible via npx.
  fix Use `npx mrm typescript` or install Mrm globally with `npm install -g mrm`.

• Error: EPERM: operation not permitted, mkdir 'src'

  cause Permission issues prevent Mrm from creating necessary directories or files in the project path.
  fix Ensure you have write permissions in the project directory. On some systems, you might need to run your terminal with elevated privileges (e.g., `sudo npx mrm typescript` on Linux/macOS or 'Run as Administrator' on Windows).

• Cannot find module 'typescript'

  cause The TypeScript package, which is a dependency managed by the task, was not successfully installed in your project's `node_modules`.
  fix After running `npx mrm typescript`, ensure you run `npm install` (or `yarn install`) to install all project dependencies, including TypeScript.

• Missing script: 'typecheck'

  cause The `typecheck` npm script was not correctly added to your `package.json` by the Mrm task.
  fix Verify your `package.json` for the presence of a `scripts.typecheck` entry. If missing, re-run `npx mrm typescript` or manually add `"typecheck": "tsc --noEmit"` to your `scripts`.

Warnings

• gotcha Ensure your Node.js environment meets the minimum requirement (>=10.13) as specified in the package's `engines` field. Using older Node.js versions may lead to unexpected errors.
  Fix: Upgrade Node.js to a compatible version (e.g., using `nvm install 18` or `nvm use 18`).
• gotcha Mrm tasks can overwrite existing configuration files. If you have an existing `tsconfig.json` or related npm scripts, review the changes made by the task to ensure they align with your project's needs.
  Fix: Back up critical configuration files before running Mrm. After the task, manually merge or adjust configurations as necessary.
• gotcha The Mrm task runner (`mrm`) must be accessible in your PATH. While `npx` handles this for global installs, ensure `mrm` itself is installed or resolvable if you're not using `npx`.
  Fix: Use `npx mrm typescript` or ensure `mrm` is installed globally (`npm install -g mrm`) and its bin directory is in your system's PATH.
• gotcha Mrm tasks are designed to be run in the root directory of your project where `package.json` resides. Running them from subdirectories can lead to incorrect file placements or configuration.
  Fix: Always navigate to your project's root directory before executing `npx mrm typescript`.
• gotcha The specific versions of TypeScript and `@types` packages installed by this task are managed by the task's internal logic. These might conflict with pre-existing versions in your `package.json` or require specific TypeScript versions for compilation.
  Fix: After running the task, check `package.json` for installed TypeScript dependencies and resolve any version conflicts manually if needed. You may need to run `npm install` again.

Install

• npm install mrm-task-typescript npm
• yarn add mrm-task-typescript yarn
• pnpm add mrm-task-typescript pnpm

Imports

• mrm-task-typescript
  wrong:

  import { typescript } from 'mrm-task-typescript';

  correct:

  npx mrm typescript

  This package is an Mrm task, designed for command-line execution, not for direct programmatic import as a module.
• mrm-task-typescript
  wrong:

  const typescript = require('mrm-task-typescript');

  correct:

  npx mrm typescript

  CommonJS `require` is not applicable as this package is a CLI task and does not expose a module API.
• mrm-task-typescript
  wrong:

  import typescript from 'mrm-task-typescript';

  correct:

  npx mrm typescript

  There is no default export; the task's functionality is accessed exclusively through the Mrm CLI.

Quickstart

Demonstrates how to create a new project, initialize npm, and apply the `mrm typescript` task to configure TypeScript, including `tsconfig.json` and a type-checking script.

import * as path from 'path';
import * as fs from 'fs';
import { execSync } from 'child_process';

const projectName = 'my-ts-project';
const projectPath = path.join(process.cwd(), projectName);

console.log(`Creating project directory: ${projectPath}`);
fs.mkdirSync(projectPath, { recursive: true });
process.chdir(projectPath);

console.log('Initializing npm...');
execSync('npm init -y', { stdio: 'inherit' });

console.log('Running mrm typescript task...');
execSync('npx mrm typescript', { stdio: 'inherit' });

console.log('\nVerifying setup:');
console.log('Content of tsconfig.json:');
console.log(fs.readFileSync('tsconfig.json', 'utf8'));

console.log('\nContent of package.json scripts:');
const packageJson = JSON.parse(fs.readFileSync('package.json', 'utf8'));
console.log(packageJson.scripts);

// Create a sample TypeScript file to demonstrate compilation
fs.mkdirSync('src', { recursive: true });
fs.writeFileSync('src/index.ts', `
function greet(name: string): string {
  return \`Hello, \${name}!\`;
}
console.log(greet("TypeScript User"));
`);

console.log('\nAttempting to run type check script...');
execSync('npm run typecheck', { stdio: 'inherit' });

console.log('\nTypeScript setup complete! To clean up, run:');
console.log(`rm -rf ${projectName}`);