feat(presets): introduce util functions to create presets

This change will allow users to easily extend existing presets to override certain options

Author: ahnpnl

src/cli/cli.spec.ts

@@ -117,20 +117,21 @@ describe('config', () => {
       '--tsconfig',
       'tsconfig.test.json',
       '--jsdom',
-      '--no-jest-preset',
+      '--jest-preset',
       '--js',
       'ts',
       '--babel',
     ]
 
-    it('should create a jest.config.json (without options)', async () => {
+    it('should create a jest.config.js (without options)', async () => {
       fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      fs.readFileSync.mockImplementation((f): any => {
-        if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
-        throw new Error('ENOENT')
-      })
-      expect.assertions(2)
+      fs.readFileSync
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        .mockImplementationOnce((f): any => {
+          if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+          throw new Error('ENOENT')
+        })
+      expect.assertions(3)
       const res = await runCli(...noOption)
 
       expect(res).toEqual({
@@ -141,26 +142,26 @@ Jest configuration written to "${normalize('/foo/bar/jest.config.js')}".
 `,
         stdout: '',
       })
-      expect(fs.writeFileSync.mock.calls).toEqual([
-        [
-          normalize('/foo/bar/jest.config.js'),
-          `/** @type {import('ts-jest').JestConfigWithTsJest} */
-module.exports = {
-  preset: 'ts-jest',
-  testEnvironment: 'node',
-};`,
-        ],
-      ])
+      expect(fs.writeFileSync.mock.calls[0][0]).toBe(normalize('/foo/bar/jest.config.js'))
+      expect(fs.writeFileSync.mock.calls[0][1]).toMatchInlineSnapshot(`
+        "/** @type {import('ts-jest').JestConfigWithTsJest} **/
+        module.exports = {
+          testEnvironment: 'node',
+          transform: {
+            '^.+.tsx?$': 'ts-jest',
+          },
+        };"
+      `)
     })
 
-    it('should create a jest.config.foo.json (with all options set)', async () => {
+    it('should create a jest.config.foo.js (with all options set)', async () => {
       fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      fs.readFileSync.mockImplementation((f): any => {
+      fs.readFileSync.mockImplementationOnce((f): any => {
         if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
         throw new Error('ENOENT')
       })
-      expect.assertions(2)
+      expect.assertions(3)
       const res = await runCli(...fullOptions, 'jest.config.foo.js')
 
       expect(res).toEqual({
@@ -171,29 +172,60 @@ Jest configuration written to "${normalize('/foo/bar/jest.config.foo.js')}".
 `,
         stdout: '',
       })
-      expect(fs.writeFileSync.mock.calls).toEqual([
-        [
-          normalize('/foo/bar/jest.config.foo.js'),
-          `const { jsWithTs: tsjPreset } = require('ts-jest/presets');
-
-/** @type {import('ts-jest').JestConfigWithTsJest} */
-module.exports = {
-  ...tsjPreset,
-  transform: {
-    '^.+\\\\.[tj]sx?$': ['ts-jest', {
-      tsconfig: 'tsconfig.test.json',
-      babelConfig: true,
-    }],
-  },
-};`,
-        ],
-      ])
+      expect(fs.writeFileSync.mock.calls[0][0]).toBe(normalize('/foo/bar/jest.config.foo.js'))
+      expect(fs.writeFileSync.mock.calls[0][1]).toMatchInlineSnapshot(`
+        "/** @type {import('ts-jest').JestConfigWithTsJest} **/
+        module.exports = {
+          testEnvironment: 'jsdom',
+          transform: {
+            '^.+.[tj]sx?$': 
+                [
+                  'ts-jest',
+                  {
+                    tsconfig: 'tsconfig.test.json'
+                  }
+                ]
+              ,
+          },
+        };"
+      `)
+    })
+
+    it('should create jest config with type "module" package.json', async () => {
+      fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
+      fs.readFileSync
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        .mockImplementationOnce((f): any => {
+          if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0', type: 'module' })
+          throw new Error('ENOENT')
+        })
+      expect.assertions(3)
+      const res = await runCli(...noOption)
+
+      expect(res).toEqual({
+        exitCode: 0,
+        log: '',
+        stderr: `
+Jest configuration written to "${normalize('/foo/bar/jest.config.js')}".
+`,
+        stdout: '',
+      })
+      expect(fs.writeFileSync.mock.calls[0][0]).toBe(normalize('/foo/bar/jest.config.js'))
+      expect(fs.writeFileSync.mock.calls[0][1]).toMatchInlineSnapshot(`
+        "/** @type {import('ts-jest').JestConfigWithTsJest} **/
+        export default {
+          testEnvironment: 'node',
+          transform: {
+            '^.+.tsx?$': 'ts-jest',
+          },
+        };"
+      `)
     })
 
     it('should update package.json (without options)', async () => {
       fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
       // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      fs.readFileSync.mockImplementation((f): any => {
+      fs.readFileSync.mockImplementationOnce((f): any => {
         if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
         throw new Error('ENOENT')
       })
@@ -225,12 +257,13 @@ Jest configuration written to "${normalize('/foo/bar/package.json')}".
 
     it('should update package.json (with all options set)', async () => {
       fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      fs.readFileSync.mockImplementation((f): any => {
-        if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
-        throw new Error('ENOENT')
-      })
-      expect.assertions(2)
+      fs.readFileSync
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        .mockImplementationOnce((f): any => {
+          if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0' })
+          throw new Error('ENOENT')
+        })
+      expect.assertions(3)
       const res = await runCli(...fullOptions, 'package.json')
 
       expect(res).toEqual({
@@ -241,26 +274,16 @@ Jest configuration written to "${normalize('/foo/bar/package.json')}".
 `,
         stdout: '',
       })
-      expect(fs.writeFileSync.mock.calls).toEqual([
-        [
-          normalize('/foo/bar/package.json'),
-          `{
-  "name": "mock",
-  "version": "0.0.0-mock.0",
-  "jest": {
-    "transform": {
-      "^.+\\\\.[tj]sx?$": [
-        "ts-jest",
-        {
-          "tsconfig": "tsconfig.test.json",
-          "babelConfig": true
-        }
-      ]
-    }
-  }
-}`,
-        ],
-      ])
+      expect(fs.writeFileSync.mock.calls[0][0]).toBe(normalize('/foo/bar/package.json'))
+      expect(fs.writeFileSync.mock.calls[0][1]).toMatchInlineSnapshot(`
+        "{
+          "name": "mock",
+          "version": "0.0.0-mock.0",
+          "jest": {
+            "preset": "ts-jest/presets/js-with-ts"
+          }
+        }"
+      `)
     })
 
     it('should output help', async () => {
@@ -289,46 +312,16 @@ Jest configuration written to "${normalize('/foo/bar/package.json')}".
 
         Options:
           --force               Discard any existing Jest config
-          --js ts|babel         Process .js files with ts-jest if 'ts' or with
+          --js ts|babel         Process '.js' files with ts-jest if 'ts' or with
                                 babel-jest if 'babel'
-          --no-jest-preset      Disable the use of Jest presets
+          --jest-preset         Toggle using preset
           --tsconfig <file>     Path to the tsconfig.json file
-          --babel               Pipe babel-jest after ts-jest
-          --jsdom               Use jsdom as test environment instead of node
+          --babel               Enable using Babel to process 'js' resulted content from 'ts-jest' processing
+          --jsdom               Use 'jsdom' as test environment instead of 'node'
         ",
         }
       `)
     })
-
-    it('should create jest config with type "module" package.json', async () => {
-      fs.existsSync.mockImplementation((f) => f === FAKE_PKG)
-      // eslint-disable-next-line @typescript-eslint/no-explicit-any
-      fs.readFileSync.mockImplementation((f): any => {
-        if (f === FAKE_PKG) return JSON.stringify({ name: 'mock', version: '0.0.0-mock.0', type: 'module' })
-        throw new Error('ENOENT')
-      })
-      expect.assertions(2)
-      const res = await runCli(...noOption)
-
-      expect(res).toEqual({
-        exitCode: 0,
-        log: '',
-        stderr: `
-Jest configuration written to "${normalize('/foo/bar/jest.config.js')}".
-`,
-        stdout: '',
-      })
-      expect(fs.writeFileSync.mock.calls).toEqual([
-        [
-          normalize('/foo/bar/jest.config.js'),
-          `/** @type {import('ts-jest').JestConfigWithTsJest} */
-export default {
-  preset: 'ts-jest',
-  testEnvironment: 'node',
-};`,
-        ],
-      ])
-    })
   })
 
   describe('migrate', () => {

src/cli/config/init.ts

@@ -7,11 +7,13 @@
 import { existsSync, readFileSync, writeFileSync } from 'fs'
 import { basename, join } from 'path'
 
+import ejs from 'ejs'
 import { stringify as stringifyJson5 } from 'json5'
 
 import type { CliCommand, CliCommandArgs } from '..'
+import { JEST_CONFIG_EJS_TEMPLATE, TS_JS_TRANSFORM_PATTERN, TS_TRANSFORM_PATTERN } from '../../constants'
 import type { JestConfigWithTsJest, TsJestTransformerOptions } from '../../types'
-import { type TsJestPresetDescriptor, defaults, jsWIthBabel, jsWithTs } from '../helpers/presets'
+import { type TsJestPresetDescriptor, defaults, jsWIthBabel, jsWithTs, JestPresetNames } from '../helpers/presets'
 
 /**
  * @internal
@@ -107,34 +109,38 @@ export const run: CliCommand = async (args: CliCommandArgs /* , logger: Logger *
     }
     body = JSON.stringify({ ...pkgJson, jest: jestConfig }, undefined, '  ')
   } else {
-    // js config
-    const content: string[] = []
-    if (!jestPreset) {
-      content.push(`${preset.jsImport('tsjPreset')};`, '')
-    }
-    content.push(`/** @type {import('ts-jest').JestConfigWithTsJest} */`)
-    const usesModules = pkgJson.type === 'module'
-    content.push(usesModules ? 'export default {' : 'module.exports = {')
-
-    if (jestPreset) {
-      content.push(`  preset: '${preset.name}',`)
-    } else {
-      content.push('  ...tsjPreset,')
-    }
-    if (!jsdom) content.push("  testEnvironment: 'node',")
-
-    if (tsconfig || shouldPostProcessWithBabel) {
-      content.push('  transform: {')
-      content.push("    '^.+\\\\.[tj]sx?$': ['ts-jest', {")
-      if (tsconfig) content.push(`      tsconfig: ${stringifyJson5(tsconfig)},`)
-      if (shouldPostProcessWithBabel) content.push('      babelConfig: true,')
-      content.push('    }],')
-      content.push('  },')
+    let transformPattern = TS_TRANSFORM_PATTERN
+    let transformValue = !tsconfig
+      ? `'ts-jest'`
+      : `
+        [
+          'ts-jest',
+          {
+            tsconfig: ${stringifyJson5(tsconfig)}
+          }
+        ]
+      `
+    if (preset.name === JestPresetNames.jsWithTs) {
+      transformPattern = TS_JS_TRANSFORM_PATTERN
+    } else if (preset.name === JestPresetNames.jsWIthBabel) {
+      transformValue = !tsconfig
+        ? `'ts-jest'`
+        : `
+        [
+          'ts-jest',
+          {
+            babelConfig: true,
+            tsconfig: ${stringifyJson5(tsconfig)}
+          }
+        ]
+      `
     }
-    content.push('};')
-
-    // join all together
-    body = content.join('\n')
+    body = ejs.render(JEST_CONFIG_EJS_TEMPLATE, {
+      exportKind: pkgJson.type === 'module' ? 'export default' : 'module.exports =',
+      testEnvironment: jsdom ? 'jsdom' : 'node',
+      transformPattern,
+      transformValue,
+    })
   }
 
   writeFileSync(filePath, body)
@@ -160,11 +166,11 @@ Arguments:
 
 Options:
   --force               Discard any existing Jest config
-  --js ts|babel         Process .js files with ts-jest if 'ts' or with
+  --js ts|babel         Process '.js' files with ts-jest if 'ts' or with
                         babel-jest if 'babel'
-  --no-jest-preset      Disable the use of Jest presets
+  --jest-preset         Toggle using preset
   --tsconfig <file>     Path to the tsconfig.json file
-  --babel               Pipe babel-jest after ts-jest
-  --jsdom               Use jsdom as test environment instead of node
+  --babel               Enable using Babel to process 'js' resulted content from 'ts-jest' processing
+  --jsdom               Use 'jsdom' as test environment instead of 'node'
 `)
 }

src/cli/index.ts

@@ -2,6 +2,7 @@ import { LogContexts, type Logger } from 'bs-logger'
 import type { Arguments } from 'yargs'
 import yargsParser from 'yargs-parser'
 
+import type { TsJestTransformerOptions } from '../types'
 import { rootLogger } from '../utils'
 
 const VALID_COMMANDS = ['help', 'config:migrate', 'config:init']
@@ -11,7 +12,14 @@ const logger = rootLogger.child({ [LogContexts.namespace]: 'cli', [LogContexts.a
 /**
  * @internal
  */
-export type CliCommandArgs = Omit<Arguments, '$0'> & { _: Array<string | number> }
+export type CliCommandArgs = Omit<Arguments, '$0'> & { _: Array<string | number> } & {
+  jestPreset?: boolean
+  force?: boolean
+  tsconfig?: TsJestTransformerOptions['tsconfig']
+  babel?: boolean
+  jsdom?: boolean
+  js?: 'ts' | 'babel'
+}
 /**
  * @internal
  */