fix: generate sourcemaps on .ts and .tsx files

lib/simple_tsify.js

@@ -15,29 +15,41 @@ const isJson = (code) => {
 // It means it should check types whenever spec file is changed
 // and it slows down the test speed a lot.
 // We skip this slow type-checking process by using transpileModule() api.
-module.exports = function (filePath, opts) {
+module.exports = function (fileName, opts) {
+  const ts = opts.typescript
   const chunks = []
-  const ext = path.extname(filePath)
+  const ext = path.extname(fileName)
 
   return through(
     (buf, enc, next) => {
       chunks.push(buf.toString())
       next()
     },
     function (next) {
-      const ts = opts.typescript
       const text = chunks.join('')
 
       if (isJson(text)) {
         this.push(text)
       } else {
-        this.push(ts.transpileModule(text, {
-          compilerOptions: {
-            esModuleInterop: true,
-            jsx: ext === '.tsx' || ext === '.jsx' || ext === '.js' ? 'react' : undefined,
-            downlevelIteration: true,
-          },
-        }).outputText)
+        this.push(
+          ts.transpileModule(text, {
+            // explicitly name the file here
+            // for sourcemaps
+            fileName,
+            compilerOptions: {
+              esModuleInterop: true,
+              // inline the source maps into the file
+              // https://github.com/cypress-io/cypress-browserify-preprocessor/issues/48
+              inlineSourceMap: true,
+              inlineSources: true,
+              jsx:
+                ext === '.tsx' || ext === '.jsx' || ext === '.js'
+                  ? 'react'
+                  : undefined,
+              downlevelIteration: true,
+            },
+          }).outputText,
+        )
       }
 
       next()

test/e2e/e2e_spec.js

@@ -1,6 +1,8 @@
+const _ = require('lodash')
 const chai = require('chai')
 const path = require('path')
 const snapshot = require('snap-shot-it')
+const Bluebird = require('bluebird')
 
 process.env.__TESTING__ = true
 
@@ -10,6 +12,8 @@ const preprocessor = require('../../index')
 /* eslint-disable-next-line no-unused-vars */
 const expect = chai.expect
 
+const typescript = require.resolve('typescript')
+
 beforeEach(() => {
   fs.removeSync(path.join(__dirname, '_test-output'))
   preprocessor.reset()
@@ -21,13 +25,37 @@ const DEFAULT_OPTIONS = { browserifyOptions: { debug: false } }
 const bundle = (fixtureName, options = DEFAULT_OPTIONS) => {
   const on = () => {}
   const filePath = path.join(__dirname, '..', 'fixtures', fixtureName)
-  const outputPath = path.join(__dirname, '..', '_test-output', 'output.js')
+  const outputPath = path.join(__dirname, '..', '_test-output', fixtureName)
 
   return preprocessor(options)({ filePath, outputPath, on }).then(() => {
     return fs.readFileSync(outputPath).toString()
   })
 }
 
+const parseSourceMap = (output) => {
+  return _
+  .chain(output)
+  .split('//# sourceMappingURL=data:application/json;charset=utf-8;base64,')
+  .last()
+  .thru((str) => {
+    const base64 = Buffer.from(str, 'base64').toString()
+
+    return JSON.parse(base64)
+  })
+  .value()
+}
+
+const verifySourceContents = ({ sources, sourcesContent }) => {
+  const zippedArrays = _.zip(sources, sourcesContent)
+
+  return Bluebird.map(zippedArrays, ([sourcePath, sourceContent]) => {
+    return fs.readFileAsync(sourcePath, 'utf8')
+    .then((str) => {
+      expect(str).to.eq(sourceContent)
+    })
+  })
+}
+
 describe('browserify preprocessor - e2e', () => {
   it('correctly preprocesses the file', () => {
     return bundle('example_spec.js').then((output) => {
@@ -50,7 +78,6 @@ describe('browserify preprocessor - e2e', () => {
       })
     })
 
-
     it('handles module.exports and import', () => {
       return bundle('sub_spec.js').then((output) => {
         // check that bundled tests work
@@ -88,16 +115,45 @@ describe('browserify preprocessor - e2e', () => {
   describe('typescript', () => {
     it('handles .ts file when the path is given', () => {
       return bundle('typescript/math_spec.ts', {
-        typescript: require.resolve('typescript'),
+        typescript,
       }).then((output) => {
         // check that bundled tests work
         eval(output)
+
+        const sourceMap = parseSourceMap(output)
+
+        expect(sourceMap.sources).to.deep.eq([
+          'node_modules/browser-pack/_prelude.js',
+          'test/fixtures/typescript/math.ts',
+          'test/fixtures/typescript/math_spec.ts',
+        ])
+
+        return verifySourceContents(sourceMap)
+      })
+    })
+
+    it('handles simple .tsx file with imports', () => {
+      return bundle('typescript/simple.spec.tsx', {
+        typescript,
+      }).then((output) => {
+        // check that bundled tests work
+        eval(output)
+
+        const sourceMap = parseSourceMap(output)
+
+        expect(sourceMap.sources).to.deep.eq([
+          'node_modules/browser-pack/_prelude.js',
+          'test/fixtures/typescript/math.ts',
+          'test/fixtures/typescript/simple.spec.tsx',
+        ])
+
+        return verifySourceContents(sourceMap)
       })
     })
 
     it('handles .tsx file when the path is given', () => {
       return bundle('typescript/react_spec.tsx', {
-        typescript: require.resolve('typescript'),
+        typescript,
       }).then((output) => {
         // check that bundled tests work
         eval(output)

test/fixtures/typescript/math.ts

@@ -1,3 +1,7 @@
+export const multiply = (a: number, b: number): number => {
+  return a * b
+}
+
 export default {
   add: (a: number, b: number) => {
     return a + b

test/fixtures/typescript/simple.spec.tsx

@@ -0,0 +1,12 @@
+import { multiply } from './math'
+
+describe('simple .tsx spec', () => {
+  it('can import another module and add', () => {
+    const EXPECTED = 6
+    const result = multiply(2, 3)
+
+    if (result !== EXPECTED) {
+      throw new Error(`multiplying 2*3 did not equal ${EXPECTED}. received: ${result}`)
+    }
+  })
+})

test/unit/index_spec.js

@@ -19,7 +19,9 @@ mockery.enable({
 mockery.registerMock('browserify', browserify)
 
 const streamApi = {
-  pipe () { return streamApi },
+  pipe () {
+    return streamApi
+  },
 }
 
 streamApi.on = sandbox.stub().returns(streamApi)
@@ -35,7 +37,9 @@ describe('browserify preprocessor', function () {
 
     const bundlerApi = this.bundlerApi = {
       bundle: sandbox.stub().returns(streamApi),
-      external () { return bundlerApi },
+      external () {
+        return bundlerApi
+      },
       close: sandbox.spy(),
       plugin: sandbox.stub(),
     }