fix(config): include AST transformer's name and version into cache key

src/__mocks__/hummy-transformer.js

@@ -0,0 +1,19 @@
+const { LogContexts, LogLevels } = require('bs-logger')
+
+function factory(tsCompiler) {
+  const logger = tsCompiler.configSet.logger.child({ namespace: 'hummy-transformer' })
+  const ts = tsCompiler.configSet.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))
+    )
+}
+
+module.exports = {
+  factory,
+  version: 1,
+}

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

@@ -59,6 +59,8 @@ Object {
   "before": Array [
     Object {
       "factory": [Function],
+      "name": "hoist-jest",
+      "version": 1,
     },
   ],
 }
@@ -71,6 +73,8 @@ Object {
   "before": Array [
     Object {
       "factory": [Function],
+      "name": "hoist-jest",
+      "version": 1,
     },
     Object {
       "factory": [Function],
@@ -90,6 +94,8 @@ Object {
   "before": Array [
     Object {
       "factory": [Function],
+      "name": "hoist-jest",
+      "version": 1,
     },
   ],
 }
@@ -106,6 +112,8 @@ Object {
   "before": Array [
     Object {
       "factory": [Function],
+      "name": "hoist-jest",
+      "version": 1,
     },
   ],
 }
@@ -118,6 +126,8 @@ Object {
   "before": Array [
     Object {
       "factory": [Function],
+      "name": "hoist-jest",
+      "version": 1,
     },
     Object {
       "factory": [Function],
@@ -127,6 +137,36 @@ Object {
 }
 `;
 
+exports[`customTransformers should return an object containing all resolved transformers: warning-log 1`] = `Array []`;
+
+exports[`customTransformers should return an object containing all resolved transformers: warning-log 2`] = `
+Array [
+  "[level:40] The AST transformer {{file}} must have an \`export const version = <your_transformer_version>",
+  "[level:40] The AST transformer {{file}} must have an \`export const name = <your_transformer_name>",
+]
+`;
+
+exports[`customTransformers should return an object containing all resolved transformers: warning-log 3`] = `
+Array [
+  "[level:40] The AST transformer {{file}} must have an \`export const version = <your_transformer_version>",
+  "[level:40] The AST transformer {{file}} must have an \`export const name = <your_transformer_name>",
+]
+`;
+
+exports[`customTransformers should return an object containing all resolved transformers: warning-log 4`] = `
+Array [
+  "[level:40] The AST transformer {{file}} must have an \`export const version = <your_transformer_version>",
+  "[level:40] The AST transformer {{file}} must have an \`export const name = <your_transformer_name>",
+]
+`;
+
+exports[`customTransformers should return an object containing all resolved transformers: warning-log 5`] = `
+Array [
+  "[level:40] The AST transformer {{file}} must have an \`export const version = <your_transformer_version>",
+  "[level:40] The AST transformer {{file}} must have an \`export const name = <your_transformer_name>",
+]
+`;
+
 exports[`isTestFile should return a boolean value whether the file matches test pattern 1`] = `true`;
 
 exports[`isTestFile should return a boolean value whether the file matches test pattern 2`] = `true`;

src/config/config-set.spec.ts

@@ -2,15 +2,17 @@
 import { join, resolve } from 'path'
 
 import type { Transformer } from '@jest/transform'
-import { testing } from 'bs-logger'
+import { LogLevels, testing } from 'bs-logger'
 import ts from 'typescript'
 
 import { createConfigSet } from '../__helpers__/fakers'
 import { logTargetMock } from '../__helpers__/mocks'
-import type { TsJestGlobalOptions } from '../types'
+import type { AstTransformerDesc, TsJestGlobalOptions } from '../types'
 import * as _backports from '../utils/backports'
 import { getPackageVersion } from '../utils/get-package-version'
+import { stringify } from '../utils/json'
 import { normalizeSlashes } from '../utils/normalize-slashes'
+import { sha1 } from '../utils/sha1'
 import { mocked } from '../utils/testing'
 
 import { ConfigSet, MY_DIGEST } from './config-set'
@@ -158,7 +160,9 @@ describe('customTransformers', () => {
       ],
     },
   ])('should return an object containing all resolved transformers', (data) => {
+    const logger = testing.createLoggerMock()
     const cs = createConfigSet({
+      logger,
       jestConfig: {
         rootDir: 'src',
         cwd: 'src',
@@ -169,6 +173,9 @@ describe('customTransformers', () => {
       resolve: null,
     })
 
+    expect(
+      logger.target.filteredLines(LogLevels.warn).map((logLine) => logLine.substring(0, logLine.indexOf('>') + 1)),
+    ).toMatchSnapshot('warning-log')
     expect(cs.resolvedTransformers).toMatchSnapshot()
   })
 })
@@ -335,23 +342,51 @@ describe('babelJestTransformer', () => {
 
 describe('tsCacheDir', () => {
   const cacheName = 'configSetTmp'
-  const cacheDir = join(process.cwd(), cacheName)
+  const cacheDir = join(cacheName)
   const partialTsJestCacheDir = join(cacheDir, 'ts-jest')
 
-  it.each([undefined, Object.create(null)])(
+  it.each([
+    undefined,
+    {
+      'ts-jest': {
+        astTransformers: {
+          before: ['hummy-transformer'],
+        },
+      },
+    },
+  ])(
     'should return value from which is the combination of ts jest config and jest config when running test with cache',
     (data) => {
-      expect(
-        // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
-        createConfigSet({
-          jestConfig: {
-            cache: true,
-            cacheDirectory: cacheDir,
-            globals: data,
-          },
-          resolve: null,
-        }).tsCacheDir!.indexOf(partialTsJestCacheDir),
-      ).toEqual(0)
+      const configSet = createConfigSet({
+        jestConfig: {
+          cache: true,
+          cacheDirectory: cacheDir,
+          globals: data,
+        },
+        resolve: null,
+      })
+
+      expect(configSet.cacheSuffix).toEqual(
+        sha1(
+          stringify({
+            version: configSet.compilerModule.version,
+            digest: configSet.tsJestDigest,
+            babelConfig: configSet.babelConfig,
+            tsconfig: {
+              options: configSet.parsedTsConfig.options,
+              raw: configSet.parsedTsConfig.raw,
+            },
+            isolatedModules: configSet.isolatedModules,
+            // @ts-expect-error testing purpose
+            diagnostics: configSet._diagnostics,
+            transformers: Object.values(configSet.resolvedTransformers)
+              .reduce((prevVal, currentVal) => [...prevVal, currentVal])
+              .map((transformer: AstTransformerDesc) => `${transformer.name}-${transformer.version}`),
+          }),
+        ),
+      )
+      // eslint-disable-next-line @typescript-eslint/no-non-null-assertion
+      expect(configSet.tsCacheDir!.indexOf(partialTsJestCacheDir)).toEqual(0)
     },
   )
 

src/config/config-set.ts

@@ -299,13 +299,24 @@ export class ConfigSet {
     this.resolvedTransformers.before = [require('../transformers/hoist-jest')]
     const { astTransformers } = options
     if (astTransformers) {
+      const resolveTransformerFunc = (transformerPath: string) => {
+        const transformerFunc = require(transformerPath)
+        if (!transformerFunc.version) {
+          this.logger.warn(Errors.MissingTransformerVersion, { file: transformerPath })
+        }
+        if (!transformerFunc.name) {
+          this.logger.warn(Errors.MissingTransformerName, { file: transformerPath })
+        }
+
+        return transformerFunc
+      }
       const resolveTransformers = (transformers: Array<string | AstTransformer>): AstTransformerDesc[] =>
         transformers.map((transformer) => {
           if (typeof transformer === 'string') {
-            return require(this.resolvePath(transformer, { nodeResolve: true }))
+            return resolveTransformerFunc(this.resolvePath(transformer, { nodeResolve: true }))
           } else {
             return {
-              ...require(this.resolvePath(transformer.path, { nodeResolve: true })),
+              ...resolveTransformerFunc(this.resolvePath(transformer.path, { nodeResolve: true })),
               options: transformer.options,
             }
           }
@@ -356,14 +367,15 @@ export class ConfigSet {
         version: this.compilerModule.version,
         digest: this.tsJestDigest,
         babelConfig: this.babelConfig,
-        compilerModule: this.compilerModule,
         tsconfig: {
           options: this.parsedTsConfig.options,
           raw: this.parsedTsConfig.raw,
         },
         isolatedModules: this.isolatedModules,
         diagnostics: this._diagnostics,
-        transformers: this.resolvedTransformers,
+        transformers: Object.values(this.resolvedTransformers)
+          .reduce((prevVal, currentVal) => [...prevVal, currentVal])
+          .map((transformer: AstTransformerDesc) => `${transformer.name}-${transformer.version}`),
       }),
     )
     if (!this._jestCfg.cache) {

src/transformers/README.md

@@ -9,6 +9,14 @@ import { SourceFile, TransformationContext, Transformer, Visitor } from 'typescr
 
 import type { TsCompilerInstance } from 'ts-jest/dist/types'
 
+/**
+ * Remember to increase the version whenever transformer's content is changed. This is to inform Jest to not reuse
+ * the previous cache which contains old transformer's content
+ */
+export const version = 1
+// Used for constructing cache key
+export const name = 'hoist-jest'
+
 export function factory(compilerInstance: TsCompilerInstance) {
   const ts = compilerInstance.configSet.compilerModule
   function createVisitor(ctx: TransformationContext, sf: SourceFile) {

src/transformers/hoist-jest.ts

@@ -13,6 +13,14 @@ import type {
 
 import type { TsCompilerInstance } from '../types'
 
+/**
+ * Remember to increase the version whenever transformer's content is changed. This is to inform Jest to not reuse
+ * the previous cache which contains old transformer's content
+ */
+export const version = 1
+// Used for constructing cache key
+export const name = 'hoist-jest'
+
 /**
  * What methods of `jest` we should hoist
  */

src/transformers/path-mapping.ts

@@ -11,6 +11,14 @@ import type * as _ts from 'typescript'
 
 import type { TsCompilerInstance } from '../types'
 
+/**
+ * Remember to increase the version whenever transformer's content is changed. This is to inform Jest to not reuse
+ * the previous cache which contains old transformer's content
+ */
+export const version = 1
+// Used for constructing cache key
+export const name = 'hoist-jest'
+
 const isBaseDir = (base: string, dir: string) => !relative(base, dir)?.startsWith('.')
 
 /**

src/utils/messages.ts

@@ -19,6 +19,8 @@ export const enum Errors {
   MismatchNodeTargetMapping = 'There is a mismatch between your NodeJs version {{nodeJsVer}} and your TypeScript target {{compilationTarget}}. This might lead to some unexpected errors when running tests with `ts-jest`. To fix this, you can check https://github.com/microsoft/TypeScript/wiki/Node-Target-Mapping',
   CannotProcessFileReturnOriginal = "Unable to process '{{file}}', falling back to original file content. You can also configure Jest config option `transformIgnorePatterns` to ignore {{file}} from transformation or make sure that `outDir` in your tsconfig is neither `''` or `'.'`",
   CannotProcessFile = "Unable to process '{{file}}', please make sure that `outDir` in your tsconfig is neither `''` or `'.'`. You can also configure Jest config option `transformIgnorePatterns` to inform `ts-jest` to transform {{file}}",
+  MissingTransformerName = 'The AST transformer {{file}} must have an `export const name = <your_transformer_name>`',
+  MissingTransformerVersion = 'The AST transformer {{file}} must have an `export const version = <your_transformer_version>`',
 }
 
 /**