fix: Handle when transpileOnly option is used (#94)

lib/typescript-overrides.ts

@@ -1,21 +1,29 @@
 const debug = require('debug')('cypress:webpack')
+const _ = require('lodash')
+
+import { CompilerOptions, CreateProgramOptions } from 'typescript'
 
 let sourceMapOverride: null | boolean = null
 
+export const getProgramOptions = (rootNamesOrOptions: CreateProgramOptions, options: CompilerOptions): CompilerOptions => {
+  return _.isArray(rootNamesOrOptions) ? options : rootNamesOrOptions.options
+}
+
 export const tryRequireTypescript = () => {
   try {
     // reset each time this is called
     sourceMapOverride = null
 
-    const typescript = require('typescript')
+    const typescript = require('typescript') as typeof import('typescript')
 
     debug('typescript found, overriding typescript.createProgram()')
 
     const { createProgram } = typescript
 
-    typescript.createProgram = (...args: [any]) => {
-      const [programOptions] = args
-      const { options } = programOptions
+    typescript.createProgram = (...args: any[]) => {
+      const [rootNamesOrOptions, _options] = args
+
+      const options = getProgramOptions(rootNamesOrOptions, _options)
 
       debug('typescript unmodified createProgram options %o', options)
 
@@ -31,6 +39,7 @@ export const tryRequireTypescript = () => {
         debug('typescript modified createProgram options %o', options)
       }
 
+      // @ts-ignore
       return createProgram.apply(typescript, args)
     }
 

test/unit/typescript-overrides.spec.ts

@@ -117,5 +117,26 @@ describe('./lib/typescript-overrides', () => {
         },
       })
     })
+
+    it('sets options when given an array', () => {
+      const typescriptOverrides = proxyquire('../../lib/typescript-overrides', {
+        typescript,
+      })
+
+      typescriptOverrides.overrideSourceMaps(true)
+
+      expect(typescriptOverrides.getSourceMapOverride()).to.be.true
+
+      typescript.createProgram([], {
+        sourceMap: false,
+        inlineSources: true,
+        inlineSourceMap: true,
+      })
+
+      expect(createProgram).to.be.calledOn(typescript)
+      expect(createProgram).to.be.calledWith([], {
+        sourceMap: true,
+      })
+    })
   })
 })