feat(config): support after and afterDeclarations AST transformers

docs/user/config/astTransformers.md

@@ -5,7 +5,12 @@ title: AST transformers option
 `ts-jest` by default does hoisting for a few `jest` methods via a TypeScript AST transformer. One can also create custom
 TypeScript AST transformers and provide them to `ts-jest` to include into compilation process.
 
-The option is `astTransformers` and it allows ones to specify which TypeScript AST transformers to use with `ts-jest`.
+The option is `astTransformers` and it allows ones to specify which 3 types of TypeScript AST transformers to use with `ts-jest`:
+
+- `before` means your transformers get run before TS ones, which means your transformers will get raw TS syntax 
+instead of transpiled syntax (e.g `import` instead of `require` or `define` ).
+- `after` means your transformers get run after TS ones, which gets transpiled syntax.
+- `afterDeclarations` means your transformers get run during `d.ts` generation phase, allowing you to transform output type declarations.
 
 ### Examples
 
@@ -17,7 +22,9 @@ module.exports = {
   // [...]
   globals: {
     'ts-jest': {
-      astTransformers: ['my-custom-transformer'],
+      astTransformers: {
+        before: ['my-custom-transformer'],
+      },
     }
   }
 };
@@ -32,7 +39,9 @@ module.exports = {
   "jest": {
     "globals": {
       "ts-jest": {
-        astTransformers: ['my-custom-transformer'],
+        astTransformers: {
+          "before": ["my-custom-transformer"]
+        }
       }
     }
   }
@@ -43,5 +52,4 @@ module.exports = {
 
 ### Writing custom TypeScript AST transformers
 
-To write a custom TypeScript AST transformers, one can take a look at the one that `ts-jest` is using at
-https://github.com/kulshekhar/ts-jest/tree/master/src/transformers
+To write a custom TypeScript AST transformers, one can take a look at [the one](https://github.com/kulshekhar/ts-jest/tree/master/src/transformers) that `ts-jest` is using.

e2e/__tests__/__snapshots__/logger.test.ts.snap

@@ -124,6 +124,117 @@ Array [
 ]
 `;
 
+exports[`ts-jest logging deprecation warning with astTransformers config as an object should pass using template "default" 1`] = `
+  √ jest
+  ↳ exit code: 0
+  ===[ STDOUT ]===================================================================
+
+  ===[ STDERR ]===================================================================
+  PASS ./Hello.spec.ts
+    Hello Class
+      √ should create a new Hello
+
+  Test Suites: 1 passed, 1 total
+  Tests:       1 passed, 1 total
+  Snapshots:   0 total
+  Time:        XXs
+  Ran all test suites.
+  ================================================================================
+`;
+
+exports[`ts-jest logging deprecation warning with astTransformers config as an object should pass using template "with-babel-7" 1`] = `
+  √ jest
+  ↳ exit code: 0
+  ===[ STDOUT ]===================================================================
+
+  ===[ STDERR ]===================================================================
+  PASS ./Hello.spec.ts
+    Hello Class
+      √ should create a new Hello
+
+  Test Suites: 1 passed, 1 total
+  Tests:       1 passed, 1 total
+  Snapshots:   0 total
+  Time:        XXs
+  Ran all test suites.
+  ================================================================================
+`;
+
+exports[`ts-jest logging deprecation warning with astTransformers config as an object should pass using template "with-babel-7-string-config" 1`] = `
+  √ jest
+  ↳ exit code: 0
+  ===[ STDOUT ]===================================================================
+
+  ===[ STDERR ]===================================================================
+  PASS ./Hello.spec.ts
+    Hello Class
+      √ should create a new Hello
+
+  Test Suites: 1 passed, 1 total
+  Tests:       1 passed, 1 total
+  Snapshots:   0 total
+  Time:        XXs
+  Ran all test suites.
+  ================================================================================
+`;
+
+exports[`ts-jest logging deprecation warning with astTransformers config as string array should pass using template "default" 1`] = `
+  √ jest
+  ↳ exit code: 0
+  ===[ STDOUT ]===================================================================
+
+  ===[ STDERR ]===================================================================
+  ts-jest[config] (WARN) The configuration for astTransformers as string[] is deprecated and will be removed in ts-jest 27. Please define your custom AST transformers in a form of an object. More information you can check online documentation https://kulshekhar.github.io/ts-jest/user/config/astTransformers
+  PASS ./Hello.spec.ts
+    Hello Class
+      √ should create a new Hello
+
+  Test Suites: 1 passed, 1 total
+  Tests:       1 passed, 1 total
+  Snapshots:   0 total
+  Time:        XXs
+  Ran all test suites.
+  ================================================================================
+`;
+
+exports[`ts-jest logging deprecation warning with astTransformers config as string array should pass using template "with-babel-7" 1`] = `
+  √ jest
+  ↳ exit code: 0
+  ===[ STDOUT ]===================================================================
+
+  ===[ STDERR ]===================================================================
+  ts-jest[config] (WARN) The configuration for astTransformers as string[] is deprecated and will be removed in ts-jest 27. Please define your custom AST transformers in a form of an object. More information you can check online documentation https://kulshekhar.github.io/ts-jest/user/config/astTransformers
+  PASS ./Hello.spec.ts
+    Hello Class
+      √ should create a new Hello
+
+  Test Suites: 1 passed, 1 total
+  Tests:       1 passed, 1 total
+  Snapshots:   0 total
+  Time:        XXs
+  Ran all test suites.
+  ================================================================================
+`;
+
+exports[`ts-jest logging deprecation warning with astTransformers config as string array should pass using template "with-babel-7-string-config" 1`] = `
+  √ jest
+  ↳ exit code: 0
+  ===[ STDOUT ]===================================================================
+
+  ===[ STDERR ]===================================================================
+  ts-jest[config] (WARN) The configuration for astTransformers as string[] is deprecated and will be removed in ts-jest 27. Please define your custom AST transformers in a form of an object. More information you can check online documentation https://kulshekhar.github.io/ts-jest/user/config/astTransformers
+  PASS ./Hello.spec.ts
+    Hello Class
+      √ should create a new Hello
+
+  Test Suites: 1 passed, 1 total
+  Tests:       1 passed, 1 total
+  Snapshots:   0 total
+  Time:        XXs
+  Ran all test suites.
+  ================================================================================
+`;
+
 exports[`ts-jest logging with unsupported version test with TS_JEST_DISABLE_VER_CHECKER is not set in process.env should pass using template "with-unsupported-version" 1`] = `
   √ jest
   ↳ exit code: 0

e2e/__tests__/logger.test.ts

@@ -47,7 +47,7 @@ describe('ts-jest logging', () => {
         const filteredEntries = result.logFileEntries
           // keep only debug and above
           .filter(m => (m.context[LogContexts.logLevel] || 0) >= LogLevels.debug)
-          // simplify entires
+          // simplify entries
           // eslint-disable-next-line @typescript-eslint/restrict-template-expressions
           .map(e => result.normalize(`[level:${e.context[LogContexts.logLevel]}] ${e.message}`))
         expect(filteredEntries).toMatchSnapshot()
@@ -90,4 +90,38 @@ describe('ts-jest logging', () => {
       })
     })
   }
+
+  describe('deprecation warning', () => {
+    describe('with astTransformers config as string array', () => {
+      const testCase = configureTestCase('simple', {
+        tsJestConfig: {
+          astTransformers: []
+        }
+      })
+
+      testCase.runWithTemplates(allValidPackageSets, 0, (runTest, { testLabel }) => {
+        it(testLabel, () => {
+          const result = runTest()
+          expect(result.status).toBe(0)
+          expect(result).toMatchSnapshot()
+        })
+      })
+    })
+
+    describe('with astTransformers config as an object', () => {
+      const testCase = configureTestCase('simple', {
+        tsJestConfig: {
+          astTransformers: {}
+        }
+      })
+
+      testCase.runWithTemplates(allValidPackageSets, 0, (runTest, { testLabel }) => {
+        it(testLabel, () => {
+          const result = runTest()
+          expect(result.status).toBe(0)
+          expect(result).toMatchSnapshot()
+        })
+      })
+    })
+  })
 })

src/__helpers__/fakers.ts

@@ -16,7 +16,7 @@ export function tsJestConfig(options?: Partial<TsJestConfig>): TsJestConfig {
   return {
     isolatedModules: false,
     compiler: 'typescript',
-    transformers: [],
+    transformers: options?.transformers ?? Object.create(null),
     babelConfig: undefined,
     tsConfig: undefined,
     packageJson: undefined,

src/__mocks__/dummy-transformer.js

@@ -0,0 +1,17 @@
+const { LogContexts, LogLevels } = require('bs-logger')
+
+function factory(cs) {
+  const logger = cs.logger.child({ namespace: 'dummy-transformer' })
+  const ts = cs.compilerModule
+
+  function createVisitor(_ctx, _) {
+    return (node) => node
+  }
+
+  return (ctx) =>
+    logger.wrap({ [LogContexts.logLevel]: LogLevels.debug, call: null }, 'visitSourceFileNode(): dummy', (sf) =>
+      ts.visitNode(sf, createVisitor(ctx, sf))
+    )
+}
+
+exports.factory = factory

src/compiler/instance.ts

@@ -15,7 +15,7 @@ const SOURCE_MAPPING_PREFIX = 'sourceMappingURL='
 /**
  * Update the output remapping the source map.
  */
-function updateOutput(outputText: string, normalizedFileName: string, sourceMap: string) {
+function updateOutput(outputText: string, normalizedFileName: string, sourceMap: string): string {
   const base64Map = Buffer.from(updateSourceMap(sourceMap, normalizedFileName), 'utf8').toString('base64')
   const sourceMapContent = `data:application/json;charset=utf-8;base64,${base64Map}`
 
@@ -45,7 +45,7 @@ const compileAndUpdateOutput = (compileFn: CompileFn, logger: Logger) => (
   code: string,
   fileName: string,
   lineOffset?: number,
-) => {
+): string => {
   logger.debug({ fileName }, 'compileAndUpdateOutput(): get compile output')
 
   const [value, sourceMap] = compileFn(code, fileName, lineOffset)

src/compiler/language-service.ts

@@ -7,12 +7,26 @@ import * as _ts from 'typescript'
 
 import type { ConfigSet } from '../config/config-set'
 import { LINE_FEED } from '../constants'
-import { CompilerInstance, MemoryCache, SourceOutput, TSFile } from '../types'
+import { CompilerInstance, SourceOutput } from '../types'
 import { Errors, interpolate } from '../util/messages'
 
 import { parse, stringify } from '../util/json'
 import { sha1 } from '../util/sha1'
 
+/** where key is filepath */
+type TSFiles = Map<string, TSFile>
+
+interface TSFile {
+  text?: string
+  output?: string
+  version: number
+}
+
+interface MemoryCache {
+  resolvedModules: Map<string, string[]>
+  files: TSFiles
+}
+
 function doTypeChecking(
   configs: ConfigSet,
   diagnosedFiles: string[],

src/config/__snapshots__/config-set.spec.ts.snap

@@ -1,6 +1,6 @@
 // Jest Snapshot v1, https://goo.gl/fbAQLP
 
-exports[`cacheKey should be a string 1`] = `"{\\"digest\\":\\"a0d51ca854194df8191d0e65c0ca4730f510f332\\",\\"jest\\":{\\"__backported\\":true,\\"globals\\":{}},\\"projectDepVersions\\":{\\"dev\\":\\"1.2.5\\",\\"opt\\":\\"1.2.3\\",\\"peer\\":\\"1.2.4\\",\\"std\\":\\"1.2.6\\"},\\"transformers\\":[\\"hoisting-jest-mock@1\\"],\\"tsJest\\":{\\"compiler\\":\\"typescript\\",\\"diagnostics\\":{\\"ignoreCodes\\":[6059,18002,18003],\\"pretty\\":true,\\"throws\\":true},\\"isolatedModules\\":false,\\"packageJson\\":{\\"kind\\":\\"file\\"},\\"transformers\\":[],\\"tsConfig\\":{\\"kind\\":\\"file\\",\\"value\\":\\"\\"}},\\"tsconfig\\":{\\"options\\":{\\"configFilePath\\":\\"\\",\\"declaration\\":false,\\"inlineSourceMap\\":false,\\"inlineSources\\":true,\\"module\\":1,\\"noEmit\\":false,\\"removeComments\\":false,\\"sourceMap\\":true,\\"target\\":1,\\"types\\":[]},\\"raw\\":{\\"compileOnSave\\":false,\\"compilerOptions\\":{\\"composite\\":true,\\"declaration\\":true,\\"types\\":[]},\\"exclude\\":[\\"foo/**/*\\"],\\"include\\":[\\"bar/**/*\\"]}}}"`;
+exports[`cacheKey should be a string 1`] = `"{\\"digest\\":\\"a0d51ca854194df8191d0e65c0ca4730f510f332\\",\\"jest\\":{\\"__backported\\":true,\\"globals\\":{}},\\"projectDepVersions\\":{\\"dev\\":\\"1.2.5\\",\\"opt\\":\\"1.2.3\\",\\"peer\\":\\"1.2.4\\",\\"std\\":\\"1.2.6\\"},\\"transformers\\":[\\"hoisting-jest-mock@1\\"],\\"tsJest\\":{\\"compiler\\":\\"typescript\\",\\"diagnostics\\":{\\"ignoreCodes\\":[6059,18002,18003],\\"pretty\\":true,\\"throws\\":true},\\"isolatedModules\\":false,\\"packageJson\\":{\\"kind\\":\\"file\\"},\\"transformers\\":{},\\"tsConfig\\":{\\"kind\\":\\"file\\",\\"value\\":\\"\\"}},\\"tsconfig\\":{\\"options\\":{\\"configFilePath\\":\\"\\",\\"declaration\\":false,\\"inlineSourceMap\\":false,\\"inlineSources\\":true,\\"module\\":1,\\"noEmit\\":false,\\"removeComments\\":false,\\"sourceMap\\":true,\\"target\\":1,\\"types\\":[]},\\"raw\\":{\\"compileOnSave\\":false,\\"compilerOptions\\":{\\"composite\\":true,\\"declaration\\":true,\\"types\\":[]},\\"exclude\\":[\\"foo/**/*\\"],\\"include\\":[\\"bar/**/*\\"]}}}"`;
 
 exports[`isTestFile should return a boolean value whether the file matches test pattern 1`] = `true`;
 
@@ -67,7 +67,7 @@ Object {
       "value": undefined,
     },
     "stringifyContentPathRegex": undefined,
-    "transformers": Array [],
+    "transformers": Object {},
     "tsConfig": Object {
       "kind": "file",
       "value": "",
@@ -156,6 +156,45 @@ Array [
 ]
 `;
 
+exports[`tsCustomTransformers should return an object containing all resolved transformers 1`] = `
+Object {
+  "before": Array [
+    [Function],
+  ],
+}
+`;
+
+exports[`tsCustomTransformers should return an object containing all resolved transformers 2`] = `
+Object {
+  "before": Array [
+    [Function],
+    [Function],
+  ],
+}
+`;
+
+exports[`tsCustomTransformers should return an object containing all resolved transformers 3`] = `
+Object {
+  "after": Array [
+    [Function],
+  ],
+  "before": Array [
+    [Function],
+  ],
+}
+`;
+
+exports[`tsCustomTransformers should return an object containing all resolved transformers 4`] = `
+Object {
+  "afterDeclarations": Array [
+    [Function],
+  ],
+  "before": Array [
+    [Function],
+  ],
+}
+`;
+
 exports[`tsJest should return correct defaults 1`] = `
 Object {
   "babelConfig": undefined,
@@ -175,10 +214,15 @@ Object {
     "value": undefined,
   },
   "stringifyContentPathRegex": undefined,
-  "transformers": Array [],
+  "transformers": Object {},
   "tsConfig": Object {
     "kind": "file",
     "value": undefined,
   },
 }
 `;
+
+exports[`tsJest transformers should display deprecation warning message when config transformers is string array 1`] = `
+"[level:40] The configuration for astTransformers as string[] is deprecated and will be removed in ts-jest 27. Please define your custom AST transformers in a form of an object. More information you can check online documentation https://kulshekhar.github.io/ts-jest/user/config/astTransformers
+"
+`;