test: hasNativeTSSupport mock test

Author: colinaaa

packages/rspeedy/core/src/config/loadConfig.ts

@@ -178,3 +178,7 @@ function isJavaScriptPath(configPath: string): boolean {
   const ext = extname(configPath)
   return ['.js', '.mjs', '.cjs'].includes(ext)
 }
+
+export function TEST_ONLY_hasNativeTSSupport(): boolean {
+  return hasNativeTSSupport()
+}

packages/rspeedy/core/test/config/loadConfig.test.ts

@@ -5,9 +5,12 @@ import { mkdtemp, writeFile } from 'node:fs/promises'
 import { tmpdir } from 'node:os'
 import { join } from 'node:path'
 
-import { describe, expect, test } from 'vitest'
+import { beforeEach, describe, expect, test, vi } from 'vitest'
 
-import { loadConfig } from '../../src/config/loadConfig.js'
+import {
+  TEST_ONLY_hasNativeTSSupport as hasNativeTSSupport,
+  loadConfig,
+} from '../../src/config/loadConfig.js'
 import type { Config } from '../../src/index.js'
 
 describe('Config - loadConfig', () => {
@@ -307,3 +310,57 @@ describe('Config - loadConfig', () => {
     })
   })
 })
+
+describe('hasNativeTSSupport', () => {
+  const process: {
+    env: Record<string, string>
+    features: { typescript?: false | 'strip' | 'transform' | undefined }
+  } = {
+    env: {},
+    features: {},
+  }
+
+  beforeEach(() => {
+    process.env = {}
+    process.features = {}
+    vi.stubGlobal('process', process)
+
+    return () => {
+      vi.unstubAllGlobals()
+    }
+  })
+
+  test('without features.typescript', () => {
+    expect(hasNativeTSSupport()).toBe(false)
+  })
+
+  test('with features.typescript: "transform"', () => {
+    process.features.typescript = 'transform'
+    expect(hasNativeTSSupport()).toBe(true)
+  })
+
+  test('with features.typescript: "strip"', () => {
+    process.features.typescript = 'strip'
+    expect(hasNativeTSSupport()).toBe(true)
+  })
+
+  test('with features.typescript: false', () => {
+    process.features.typescript = false
+    expect(hasNativeTSSupport()).toBe(false)
+  })
+
+  test('with features.typescript: undefined', () => {
+    process.features.typescript = undefined
+    expect(hasNativeTSSupport()).toBe(false)
+  })
+
+  test('with NODE_OPTIONS: --experimental-transform-types', () => {
+    process.env['NODE_OPTIONS'] = '--experimental-transform-types'
+    expect(hasNativeTSSupport()).toBe(true)
+  })
+
+  test('with NODE_OPTIONS: --experimental-strip-types', () => {
+    process.env['NODE_OPTIONS'] = '--experimental-strip-types'
+    expect(hasNativeTSSupport()).toBe(true)
+  })
+})