Add Vitest

Here's how we added Vitest to Kitbook written here for maintenance reference.

• pnpm -F kitbook add -D vitest
• turn on globals option and In-source testing by creating a vitest.config.ts file:

vitest.config.ts
ts
import { defineConfig } from 'vitest/config'
 
export default defineConfig({
  test: {
    globals: true,
    includeSource: ['src/**/*.ts'],
  },
})

• Acquaint Typescript:

tsconfig.json
json
{
  "compilerOptions": {
    "types": [
      "vitest/globals",
      "vitest/importMeta"
    ]
  }
}

• Add an inline test

ts
if (import.meta.vitest) {
  test('capitalize turns bar into Bar', () => {
    expect(capitalize('bar')).toMatchInlineSnapshot('"Bar"')
  })
}

• For a REPL like experience turn on VSCode autosave and run Vitest in update mode with the -u flag to have the inline snapshot update as you type.