fix: Use typescript's tsconfig.json parsing functionality instead of …

…JSON.parse (#70)

* Use typescript config parse instead of JSON.parse

* remove unused loadJSONSync

* Update ts-node tests

* proxyquire bug

* fix failing test

package.json

@@ -18,13 +18,15 @@
     "@types/lodash": "^4.14.120",
     "@types/mocha": "^5.2.5",
     "@types/node": "^10.12.18",
+    "@types/proxyquire": "^1.3.28",
     "@types/wrap-ansi": "^3.0.0",
     "chai": "^4.2.0",
     "conventional-changelog-cli": "^2.0.11",
     "fancy-test": "^1.4.3",
     "globby": "^9.0.0",
     "lodash": "^4.17.11",
     "mocha": "^5.2.0",
+    "proxyquire": "^2.1.0",
     "ts-node": "^7.0.1",
     "tslint": "^5.12.1",
     "typescript": "^3.2.4"

src/ts-node.ts

@@ -1,9 +1,9 @@
 import * as fs from 'fs'
 import * as path from 'path'
 import * as TSNode from 'ts-node'
+import {parseConfigFileTextToJson} from 'typescript'
 
 import Debug from './debug'
-import {loadJSONSync} from './util'
 
 const tsconfigs: {[root: string]: TSConfig} = {}
 const rootDirs: string[] = []
@@ -59,16 +59,18 @@ function registerTSNode(root: string) {
 }
 
 function loadTSConfig(root: string): TSConfig | undefined {
-  try {
-    // // ignore if no .git as it's likely not in dev mode
-    // if (!await fs.pathExists(path.join(this.root, '.git'))) return
-
-    const tsconfigPath = path.join(root, 'tsconfig.json')
-    const tsconfig = loadJSONSync(tsconfigPath)
-    if (!tsconfig || !tsconfig.compilerOptions) return
+  const tsconfigPath = path.join(root, 'tsconfig.json')
+  if (fs.existsSync(tsconfigPath)) {
+    const tsconfig = parseConfigFileTextToJson(
+      tsconfigPath,
+      fs.readFileSync(tsconfigPath, 'utf8')
+    ).config
+    if (!tsconfig || !tsconfig.compilerOptions) {
+      throw new Error(
+        `Could not read and parse tsconfig.json at ${tsconfigPath}, or it ` +
+        'did not contain a "compilerOptions" section.')
+    }
     return tsconfig
-  } catch (err) {
-    if (err.code !== 'ENOENT') throw err
   }
 }
 

src/util.ts

@@ -15,14 +15,6 @@ export function mapValues<T extends object, TResult>(obj: {[P in keyof T]: T[P]}
     }, {} as any)
 }
 
-export function loadJSONSync(path: string): any {
-  debug('loadJSONSync %s', path)
-  // let loadJSON
-  // try { loadJSON = require('load-json-file') } catch {}
-  // if (loadJSON) return loadJSON.sync(path)
-  return JSON.parse(fs.readFileSync(path, 'utf8'))
-}
-
 export function exists(path: string): Promise<boolean> {
   // tslint:disable-next-line
   return new Promise(resolve => fs.exists(path, resolve))

test/ts-node.test.ts

@@ -1,53 +1,48 @@
 import * as path from 'path'
+import * as proxyquire from 'proxyquire'
 import * as tsNode from 'ts-node'
 
 import {TSConfig} from '../src/ts-node'
-import * as util from '../src/util'
 
 import {expect, fancy} from './test'
 
 const root = path.resolve(__dirname, 'fixtures/typescript')
 const orig = 'src/hooks/init.ts'
 let tsNodeRegisterCallArguments: any[] = []
 
-/**
- * Delete a module from the require cache before requiring it.
- */
-export default function freshRequire(name: string) {
-  delete require.cache[require.resolve(name)]
-  return require(name)
-}
-
 const DEFAULT_TS_CONFIG: TSConfig = {
   compilerOptions: {}
 }
 
-const withMockTsConfig = (config: TSConfig = DEFAULT_TS_CONFIG) =>
-  fancy
+const withMockTsConfig = (config: TSConfig = DEFAULT_TS_CONFIG) => {
+  const tsNodePlugin = proxyquire('../src/ts-node', {fs: {
+    existsSync: () => true,
+    readFileSync: () => JSON.stringify(config)
+  }})
+
+  // This prints "loadTSConfig unstubbed" not "loadTSConfig proxyquire"!
+  tsNodePlugin.tsPath('poop', 'asdf')
+
+  return fancy
+    .add('tsNodePlugin', () => tsNodePlugin)
     .stub(tsNode, 'register', (arg: any) => {
       tsNodeRegisterCallArguments.push(arg)
     })
-    .stub(util, 'loadJSONSync', (arg: string) => {
-      if (arg.endsWith('tsconfig.json')) {
-        return config
-      }
-    })
     .finally(() => {
       tsNodeRegisterCallArguments = []
     })
+}
 
 describe('tsPath', () => {
   withMockTsConfig()
-    .it('should resolve a .ts file', () => {
-      const {tsPath} = freshRequire('../src/ts-node')
-      const result = tsPath(root, orig)
+    .it('should resolve a .ts file', ctx => {
+      const result = ctx.tsNodePlugin.tsPath(root, orig)
       expect(result).to.equal(path.join(root, orig))
     })
 
   withMockTsConfig()
-    .it('should leave esModuleInterop undefined by default', () => {
-      const {tsPath} = freshRequire('../src/ts-node')
-      tsPath(root, orig)
+    .it('should leave esModuleInterop undefined by default', ctx => {
+      ctx.tsNodePlugin.tsPath(root, orig)
       expect(tsNodeRegisterCallArguments.length).is.equal(1)
       expect(tsNodeRegisterCallArguments[0])
         .to.have.nested.property('compilerOptions.esModuleInterop')
@@ -59,9 +54,8 @@ describe('tsPath', () => {
       esModuleInterop: true
     }
   })
-    .it('should use the provided esModuleInterop option', () => {
-      const {tsPath} = freshRequire('../src/ts-node')
-      tsPath(root, orig)
+    .it('should use the provided esModuleInterop option', ctx => {
+      ctx.tsNodePlugin.tsPath(root, orig)
       expect(tsNodeRegisterCallArguments.length).is.equal(1)
       expect(tsNodeRegisterCallArguments[0])
         .to.have.nested.property('compilerOptions.esModuleInterop')