refactor(config): expose only create config set and create compiler a…

…pis (#2355)

src/ts-jest-transformer.spec.ts

@@ -1,17 +1,19 @@
 import fs from 'fs'
 import { join } from 'path'
 
-import { LogLevels } from 'bs-logger'
+import { Logger, LogLevels } from 'bs-logger'
 import { removeSync, writeFileSync } from 'fs-extra'
 import mkdirp from 'mkdirp'
 import { Extension, ResolvedModuleFull } from 'typescript'
 
 import { createConfigSet } from './__helpers__/fakers'
 import { logTargetMock } from './__helpers__/mocks'
 import { SOURCE_MAPPING_PREFIX } from './compiler/compiler-utils'
+import { TsCompiler } from './compiler/ts-compiler'
 import { TsJestCompiler } from './compiler/ts-jest-compiler'
+import { ConfigSet } from './config/config-set'
 import { CACHE_KEY_EL_SEPARATOR, TsJestTransformer } from './ts-jest-transformer'
-import type { ResolvedModulesMap } from './types'
+import type { ProjectConfigTsJest, ResolvedModulesMap, StringMap } from './types'
 import { stringify } from './utils/json'
 import { sha1 } from './utils/sha1'
 import { VersionCheckers } from './utils/version-checkers'
@@ -420,7 +422,35 @@ Array [
   })
 
   describe('subclass extends TsJestTransformer', () => {
-    class MyTransformer extends TsJestTransformer {}
+    class MyTsCompiler extends TsCompiler {
+      constructor(readonly configSet: ConfigSet, readonly jestCacheFS: StringMap) {
+        super(configSet, jestCacheFS)
+      }
+    }
+
+    class MyConfigSet extends ConfigSet {
+      constructor(readonly jestConfig: ProjectConfigTsJest, readonly parentLogger?: Logger) {
+        super(jestConfig, parentLogger)
+      }
+    }
+
+    class MyTransformer extends TsJestTransformer {
+      // @ts-expect-error testing purpose
+      // eslint-disable-next-line class-methods-use-this
+      protected _createCompiler(configSet: ConfigSet, cacheFS: Map<string, string>): MyTsCompiler {
+        return new MyTsCompiler(configSet, cacheFS)
+      }
+
+      // eslint-disable-next-line class-methods-use-this
+      protected _createConfigSet(config: ProjectConfigTsJest): MyConfigSet {
+        return new MyConfigSet(config)
+      }
+    }
+    let tr: MyTransformer
+
+    beforeEach(() => {
+      tr = new MyTransformer()
+    })
 
     test('should have jest version checking', () => {
       VersionCheckers.jest.warn = jest.fn()
@@ -429,5 +459,23 @@ Array [
 
       expect(VersionCheckers.jest.warn).toHaveBeenCalled()
     })
+
+    test('should create MyTsCompiler instance', () => {
+      // @ts-expect-error testing purpose
+      expect(tr._createCompiler(createConfigSet(), new Map())).toBeInstanceOf(MyTsCompiler)
+    })
+
+    test('should create MyConfigSet instance', () => {
+      expect(
+        // @ts-expect-error testing purpose
+        tr._createConfigSet({
+          cwd: process.cwd(),
+          extensionsToTreatAsEsm: [],
+          globals: Object.create(null),
+          testMatch: [],
+          testRegex: [],
+        }),
+      ).toBeInstanceOf(MyConfigSet)
+    })
   })
 })

src/ts-jest-transformer.ts

@@ -31,11 +31,14 @@ interface TsJestHooksMap {
   afterProcess?(args: any[], result: string | TransformedSource): string | TransformedSource | void
 }
 
-export interface DepGraphInfo {
+interface DepGraphInfo {
   fileContent: string
   resolveModuleNames: string[]
 }
 
+/**
+ * @internal
+ */
 export const CACHE_KEY_EL_SEPARATOR = '\x00'
 
 export class TsJestTransformer implements Transformer {
@@ -45,11 +48,11 @@ export class TsJestTransformer implements Transformer {
    * @internal
    */
   private static readonly _cachedConfigSets: CachedConfigSet[] = []
-  protected _compiler!: TsJestCompiler
-  protected readonly _logger: Logger
-  protected _tsResolvedModulesCachePath: string | undefined
-  protected _transformCfgStr!: string
-  protected _depGraphs: Map<string, DepGraphInfo> = new Map<string, DepGraphInfo>()
+  private readonly _logger: Logger
+  private _compiler!: TsJestCompiler
+  private _tsResolvedModulesCachePath: string | undefined
+  private _transformCfgStr!: string
+  private _depGraphs: Map<string, DepGraphInfo> = new Map<string, DepGraphInfo>()
 
   constructor() {
     this._logger = rootLogger.child({ namespace: 'ts-jest-transformer' })
@@ -58,7 +61,7 @@ export class TsJestTransformer implements Transformer {
     this._logger.debug('created new transformer')
   }
 
-  protected _configsFor(transformOptions: TransformOptionsTsJest): ConfigSet {
+  private _configsFor(transformOptions: TransformOptionsTsJest): ConfigSet {
     const { config, cacheFS } = transformOptions
     const ccs: CachedConfigSet | undefined = TsJestTransformer._cachedConfigSets.find(
       (cs) => cs.jestConfig.value === config,
@@ -90,14 +93,14 @@ export class TsJestTransformer implements Transformer {
         // create the new record in the index
         this._logger.info('no matching config-set found, creating a new one')
 
-        configSet = new ConfigSet(config)
+        configSet = this._createConfigSet(config)
         const jest = { ...config }
         // we need to remove some stuff from jest config
         // this which does not depend on config
         jest.name = undefined as any
         jest.cacheDirectory = undefined as any
         this._transformCfgStr = `${new JsonableValue(jest).serialized}${configSet.cacheSuffix}`
-        this._compiler = new TsJestCompiler(configSet, cacheFS)
+        this._compiler = this._createCompiler(configSet, cacheFS)
         this._getFsCachedResolvedModules(configSet)
         TsJestTransformer._cachedConfigSets.push({
           jestConfig: new JsonableValue(config),
@@ -113,6 +116,16 @@ export class TsJestTransformer implements Transformer {
     return configSet
   }
 
+  // eslint-disable-next-line class-methods-use-this
+  protected _createConfigSet(config: ProjectConfigTsJest): ConfigSet {
+    return new ConfigSet(config)
+  }
+
+  // eslint-disable-next-line class-methods-use-this
+  protected _createCompiler(configSet: ConfigSet, cacheFS: Map<string, string>): TsJestCompiler {
+    return new TsJestCompiler(configSet, cacheFS)
+  }
+
   /**
    * @public
    */
@@ -260,7 +273,7 @@ export class TsJestTransformer implements Transformer {
   /**
    * Subclasses extends `TsJestTransformer` can call this method to get resolved module disk cache
    */
-  protected _getFsCachedResolvedModules(configSet: ConfigSet): void {
+  private _getFsCachedResolvedModules(configSet: ConfigSet): void {
     const cacheDir = configSet.tsCacheDir
     if (!configSet.isolatedModules && cacheDir) {
       // Make sure the cache directory exists before continuing.