Set up Node Test Runner with TypeScript and ENV variables

.env

EXAMPLE_SECRET="12345"

.env.test

EXAMPLE_SECRET="6789" # Overwrites the .env one

README.md

Install

# Use whatever package manager you prefer
pnpm add -D dotenv-cli tsx glob

# For a single app in a monorepo
# pnpm add -F your-app -D dotenv-cli tsx glob

# For the global package.json in a monorepo
# pnpm add -wD dotenv-cli tsx glob

For a detailed guide, check my article (100% free, forever)

package.json

"scripts": {
	//...
	"test": "dotenv -e .env -e env.test -- glob -c \"tsx --test --test-reporter spec \" \"./test/**/*.test.ts\"",
	"build": "tsc -p tsconfig.build.json",
	//...
}

tsconfig.build.json

{
	"extends": "./tsconfig.json", // The file above. You can also just extend the base `tsconfig.json` (in the root of the monorepo) instead, adding `include: [ "./src/**/*"]`, or write the `compilerOptions` here
	"compilerOptions": {
			"noEmit": false,
			"outDir": "./dist",
	},
	"exclude": [ // This way we avoid compiling tests into JS
			"**/*.spec.ts",
			"**/*.test.ts"
	]
}

tsconfig.json

{
	"extends": "../../tsconfig.json", // Since I work in a monorepo, this one contains all generic compiler options. You can write them in this file if you prefer
	"compilerOptions": { // These are for shorter, non-relative imports in tests. Completely optional
			"baseUrl": "./",
			"paths": {
					"@src/*": ["./src/*"], 
			},
			"noEmit": true, // Avoid compiling by mistake
	},
	"include": ["./src/**/*", "./test/**/*"], // Important so tests also benefit from TS support
}