refactor(config): bring back possibility to mock logging in test (#2053)

src/__helpers__/fakers.ts

@@ -1,4 +1,5 @@
 import type { Config } from '@jest/types'
+import type { Logger } from 'bs-logger'
 import { resolve } from 'path'
 
 import { createCompilerInstance } from '../compiler/instance'
@@ -57,15 +58,17 @@ export const defaultResolve = (path: string): string => `resolved:${path}`
 export function createConfigSet({
   jestConfig,
   tsJestConfig,
+  logger, // don't change this key name, otherwise mock logging won't work
   resolve = defaultResolve,
   ...others
 }: {
   jestConfig?: Partial<Config.ProjectConfig>
   tsJestConfig?: TsJestGlobalOptions
+  logger?: Logger
   resolve?: ((path: string) => string) | null
   [key: string]: any
 } = {}): ConfigSet {
-  const cs = new ConfigSet(getJestConfig(jestConfig, tsJestConfig))
+  const cs = new ConfigSet(getJestConfig(jestConfig, tsJestConfig), logger)
   if (resolve) {
     cs.resolvePath = resolve
   }

src/config/config-set.spec.ts

@@ -1,6 +1,6 @@
 /* eslint-disable jest/no-mocks-import */
 import type { Transformer } from '@jest/transform'
-import { testing } from 'bs-logger'
+import { LogLevels, testing } from 'bs-logger'
 import { join, resolve } from 'path'
 import ts from 'typescript'
 
@@ -31,20 +31,23 @@ beforeEach(() => {
 
 describe('packageJson', () => {
   it('should not contain packageJson in final tsJest config', () => {
-    expect(
-      Object.keys(
-        createConfigSet({
-          jestConfig: {
-            globals: {
-              'ts-jest': {
-                packageJson: true,
-              },
-            },
-          } as any,
-          resolve: null,
-        }),
-      ),
-    ).not.toContain('packageJson')
+    const logger = testing.createLoggerMock()
+    createConfigSet({
+      jestConfig: {
+        globals: {
+          'ts-jest': {
+            packageJson: true,
+          },
+        },
+      } as any,
+      resolve: null,
+      logger,
+    })
+
+    expect(logger.target.filteredLines(LogLevels.warn)[0]).toMatchInlineSnapshot(`
+      "[level:40] The option \`packageJson\` is deprecated and will be removed in ts-jest 27. This option is not used by internal \`ts-jest\`
+      "
+    `)
   })
 }) // packageJson
 

src/config/config-set.ts

@@ -145,8 +145,14 @@ export class ConfigSet {
     tsBuildInfoFile: undefined,
   }
 
-  constructor(private readonly jestConfig: Config.ProjectConfig) {
-    this.logger = rootLogger.child({ [LogContexts.namespace]: 'config' })
+  constructor(
+    private readonly jestConfig: Config.ProjectConfig,
+    // mainly for testing logging
+    private readonly parentLogger?: Logger,
+  ) {
+    this.logger = this.parentLogger
+      ? this.parentLogger.child({ [LogContexts.namespace]: 'config' })
+      : rootLogger.child({ namespace: 'config' })
     this._cwd = normalize(this.jestConfig.cwd ?? process.cwd())
     this._rootDir = normalize(this.jestConfig.rootDir ?? this._cwd)
     const tsJestCfg = this.jestConfig.globals && this.jestConfig.globals['ts-jest']