feat(config): support custom AST transformers written in TypeScript (#…

…3063)

Closes #2831

e2e/__tests__/ast-transformers.test.ts

@@ -1,8 +1,14 @@
 import path from 'path'
 
+import execa from 'execa'
+
 import { json as runWithJson } from '../run-jest'
 import { runNpmInstall } from '../utils'
 
+const { createBundle } = require('../../scripts/lib/bundle')
+
+const AST_TRANSFORMERS_DIR_NAME = 'ast-transformers'
+
 const executeTest = (testDir: string): void => {
   test(`successfully runs the tests inside ${testDir} with isolatedModules: false`, () => {
     const { json } = runWithJson(testDir)
@@ -18,15 +24,56 @@ const executeTest = (testDir: string): void => {
 }
 
 describe('path-mapping', () => {
-  executeTest('ast-transformers/path-mapping')
+  executeTest(`${AST_TRANSFORMERS_DIR_NAME}/path-mapping`)
 })
 
-const TRANSFORM_OPT_DIR_NAME = 'transformer-options'
-
 describe('transformer-options', () => {
+  const TRANSFORM_OPT_DIR_NAME = 'transformer-options'
+
   beforeAll(() => {
-    runNpmInstall(path.join(__dirname, '..', 'ast-transformers', TRANSFORM_OPT_DIR_NAME))
+    runNpmInstall(path.join(__dirname, '..', AST_TRANSFORMERS_DIR_NAME, TRANSFORM_OPT_DIR_NAME))
+  })
+
+  test(`successfully runs the tests inside ${AST_TRANSFORMERS_DIR_NAME}/${TRANSFORM_OPT_DIR_NAME}`, () => {
+    const { json } = runWithJson(`${AST_TRANSFORMERS_DIR_NAME}/${TRANSFORM_OPT_DIR_NAME}`)
+
+    expect(json.success).toBe(true)
   })
+})
+
+describe('hoist-jest', () => {
+  const NON_TS_FACTORY_DIR_NAME = 'non-ts-factory'
+  const TS_FACTORY_DIR_NAME = 'ts-factory'
+
+  describe('non-ts-factory', () => {
+    const DIR = path.resolve(__dirname, '..', AST_TRANSFORMERS_DIR_NAME, 'hoist-jest', NON_TS_FACTORY_DIR_NAME)
 
-  executeTest(`ast-transformers/${TRANSFORM_OPT_DIR_NAME}`)
+    beforeAll(() => {
+      runNpmInstall(DIR)
+      const bundle = createBundle()
+      execa.sync('npm', ['install', '--no-package-lock', '--no-shrinkwrap', '--no-save', bundle], {
+        cwd: DIR,
+      })
+    })
+
+    executeTest(`${AST_TRANSFORMERS_DIR_NAME}/hoist-jest/${NON_TS_FACTORY_DIR_NAME}`)
+  })
+
+  describe('ts-factory', () => {
+    beforeAll(() => {
+      runNpmInstall(path.resolve(__dirname, '..', AST_TRANSFORMERS_DIR_NAME, 'hoist-jest', TS_FACTORY_DIR_NAME))
+    })
+
+    executeTest(`${AST_TRANSFORMERS_DIR_NAME}/hoist-jest/${TS_FACTORY_DIR_NAME}`)
+  })
+})
+
+describe('transformer-in-ts', () => {
+  const TRANSFORMER_IN_TS_DIR_NAME = `${AST_TRANSFORMERS_DIR_NAME}/transformer-in-ts`
+
+  test(`successfully runs the tests inside ${TRANSFORMER_IN_TS_DIR_NAME}`, () => {
+    const { json } = runWithJson(TRANSFORMER_IN_TS_DIR_NAME)
+
+    expect(json.success).toBe(true)
+  })
 })

e2e/hoist-jest/ts-factory/jest-isolated.config.js → e2e/ast-transformers/hoist-jest/ts-factory/jest-isolated.config.js

@@ -14,6 +14,6 @@ module.exports = {
     react$: '<rootDir>/node_modules/react',
   },
   transform: {
-    '^.+.[tj]sx?$': '<rootDir>/../../../dist/index.js',
+    '^.+.[tj]sx?$': '<rootDir>/../../../../dist/index.js',
   },
 }

e2e/hoist-jest/ts-factory/package.json → e2e/ast-transformers/hoist-jest/ts-factory/package.json

@@ -17,7 +17,7 @@
       "react$": "<rootDir>/node_modules/react"
     },
     "transform": {
-      "^.+\\.[tj]sx?$": "<rootDir>/../../../dist/index.js"
+      "^.+\\.[tj]sx?$": "<rootDir>/../../../../dist/index.js"
     }
   }
 }

e2e/ast-transformers/transformer-in-ts/__tests__/typescript.test.ts

@@ -0,0 +1,9 @@
+import { color } from '../entry'
+
+jest.mock('../entry', () => {
+  return { color: 'blue' }
+})
+
+test('should use custom AST transformer written in ts', () => {
+  expect(color).toBe('blue')
+})

e2e/ast-transformers/transformer-in-ts/entry.ts

@@ -0,0 +1,3 @@
+type Color = 'red' | 'blue'
+
+export const color: Color = 'red'

e2e/ast-transformers/transformer-in-ts/package.json

@@ -0,0 +1,14 @@
+{
+  "jest": {
+    "globals": {
+      "ts-jest": {
+        "astTransformers": {
+          "before": ["<rootDir>/../../../src/transformers/hoist-jest.ts"]
+        }
+      }
+    },
+    "transform": {
+      "^.+\\.[tj]sx?$": "<rootDir>/../../../dist/index.js"
+    }
+  }
+}