fix: correct providing a default tsconfig if none exists

lib/compilers/typescript-compiler.js

@@ -1,55 +1,12 @@
-const tsconfig = require('tsconfig')
 const ensureRequire = require('../ensure-require')
 const compileBabel = require('./babel-compiler')
 const loadBabelConfig = require('../load-babel-config.js')
-const cache = require('../cache')
-const logger = require('../logger')
-
-const defaultTypescriptConfig = {
-  'compilerOptions': {
-    'target': 'es5',
-    'lib': [
-      'dom',
-      'es6'
-    ],
-    'module': 'es2015',
-    'moduleResolution': 'node',
-    'types': ['vue-typescript-import-dts', 'jest', 'node'],
-    'isolatedModules': false,
-    'experimentalDecorators': true,
-    'noImplicitAny': true,
-    'noImplicitThis': true,
-    'strictNullChecks': true,
-    'removeComments': true,
-    'emitDecoratorMetadata': true,
-    'suppressImplicitAnyIndexErrors': true,
-    'allowSyntheticDefaultImports': true,
-    'sourceMap': true,
-    'allowJs': true
-  }
-}
-
-function getTypescriptConfig () {
-  const cachedConfig = cache.get('typescript-config')
-  if (cachedConfig) {
-    return cachedConfig
-  } else {
-    const { config } = tsconfig.loadSync(process.cwd())
-
-    if (!config) {
-      logger.info('no tsconfig.json found, defaulting to default typescript options')
-    }
-
-    const typescriptConfig = config || defaultTypescriptConfig
-    cache.set('typescript-config', typescriptConfig)
-    return typescriptConfig
-  }
-}
+const { loadTypescriptConfig } = require('../load-typescript-config')
 
 module.exports = function compileTypescript (scriptContent) {
   ensureRequire('typescript', ['typescript'])
   const typescript = require('typescript')
-  const tsConfig = getTypescriptConfig()
+  const tsConfig = loadTypescriptConfig()
 
   const res = typescript.transpileModule(scriptContent, tsConfig)
   const inputSourceMap = (res.sourceMapText !== undefined)

lib/load-typescript-config.js

@@ -0,0 +1,46 @@
+const tsconfig = require('tsconfig')
+const cache = require('./cache')
+const logger = require('./logger')
+
+const defaultTypescriptConfig = {
+  'compilerOptions': {
+    'target': 'es5',
+    'lib': [
+      'dom',
+      'es6'
+    ],
+    'module': 'es2015',
+    'moduleResolution': 'node',
+    'types': ['vue-typescript-import-dts', 'jest', 'node'],
+    'isolatedModules': false,
+    'experimentalDecorators': true,
+    'noImplicitAny': true,
+    'noImplicitThis': true,
+    'strictNullChecks': true,
+    'removeComments': true,
+    'emitDecoratorMetadata': true,
+    'suppressImplicitAnyIndexErrors': true,
+    'allowSyntheticDefaultImports': true,
+    'sourceMap': true,
+    'allowJs': true
+  }
+}
+
+module.exports.loadTypescriptConfig = function loadTypescriptConfig () {
+  const cachedConfig = cache.get('typescript-config')
+  if (cachedConfig) {
+    return cachedConfig
+  } else {
+    const { path, config } = tsconfig.loadSync(process.cwd())
+
+    if (!path) {
+      logger.info('no tsconfig.json found, defaulting to default typescript options')
+    }
+
+    const typescriptConfig = path ? config : defaultTypescriptConfig
+    cache.set('typescript-config', typescriptConfig)
+    return typescriptConfig
+  }
+}
+
+module.exports.defaultConfig = defaultTypescriptConfig

test/load-typescript-config.spec.js

@@ -0,0 +1,55 @@
+import { defaultConfig, loadTypescriptConfig } from '../lib/load-typescript-config'
+import { resolve } from 'path'
+import {
+  createReadStream,
+  createWriteStream,
+  readFileSync,
+  renameSync
+} from 'fs'
+import clearModule from 'clear-module'
+import cache from '../lib/cache'
+
+describe('load-typescript-config.js', () => {
+  beforeEach(() => {
+    cache.flushAll()
+    clearModule.all()
+  })
+
+  it('returns the default config if there is no tsconfig.json', () => {
+    const tsconfigPath = resolve(__dirname, '../tsconfig.json')
+    const tempPath = resolve(__dirname, '../.renamed')
+    renameSync(tsconfigPath, tempPath)
+
+    const tsConfig = loadTypescriptConfig()
+
+    try {
+      expect(tsConfig).toEqual(defaultConfig)
+    } catch (err) {
+      renameSync(tempPath, tsconfigPath)
+      throw err
+    }
+
+    renameSync(tempPath, tsconfigPath)
+    const tsconfigCachedConfig = loadTypescriptConfig()
+    expect(tsconfigCachedConfig).toEqual(defaultConfig)
+  })
+
+  it('reads default tsconfig if there is tsconfig.json', () => {
+    const tsconfigPath = resolve(__dirname, '../tsconfig.json')
+    const tsconfigCopiedPath = resolve(__dirname, '../.tsconfig.json_cp')
+    createReadStream(tsconfigPath).pipe(createWriteStream(tsconfigCopiedPath))
+    const tsconfigOriginal = JSON.parse(readFileSync(tsconfigPath, { encoding: 'utf8' }))
+    const tsconfig = loadTypescriptConfig()
+    expect(tsconfig).toEqual(tsconfigOriginal)
+    const tempPath = resolve(__dirname, '../.renamed')
+    renameSync(tsconfigCopiedPath, tempPath)
+    const tsconfigCached = loadTypescriptConfig()
+    try {
+      expect(tsconfig).not.toBe(tsconfigCached)
+      expect(tsconfig).toEqual(tsconfigCached)
+    } catch (err) {
+      renameSync(tempPath, tsconfigCopiedPath)
+      throw err
+    }
+  })
+})