handle server-only tests

jest.config.js

@@ -1,9 +1,40 @@
 // No need to use ts-jest https://github.com/vercel/next.js/discussions/13528#discussioncomment-22933
-// Client-side Jest config
-// You might need to setup another config file for server tests
-module.exports = {
-  // preset: "ts-jest",
-  testEnvironment: "jsdom", // might need to change for Node on the server
+
+// configuration that must be set for each project but does not change
+const commonConfig = {
+  // A map from regular expressions to paths to transformers
+  // transform: undefined,
+  transform: {
+    //"^.+\\.[jt]sx?$": "ts-jest",
+    "^.+\\.(js|jsx|ts|tsx)$": "<rootDir>/node_modules/babel-jest",
+    // MDX support
+    "^.+\\.(md|mdx)$": "jest-transformer-mdx",
+  },
+
+  // An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
+  testPathIgnorePatterns: [
+    "/node_modules/",
+    "/cypress/",
+    "/storybook/",
+    "/.next/",
+    "/stories/",
+  ],
+
+  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
+  transformIgnorePatterns: [
+    '/node_modules/',
+    '^.+\\.module\\.(css|sass|scss)$',
+  ],
+
+  // A map from regular expressions to module names that allow to stub out resources with a single module
+  moduleNameMapper: {
+    "~/(.*)": "<rootDir>/src/$1",
+    "@vulcanjs/(.*)": "<rootDir>/packages/@vulcanjs/$1",
+  },
+
+  // The directory where Jest should output its coverage files
+  coverageDirectory: "coverage-unit",
+
   // All imported modules in your tests should be mocked automatically
   // automock: false,
 
@@ -22,29 +53,6 @@ module.exports = {
   // Indicates whether the coverage information should be collected while executing the test
   // collectCoverage: false,
 
-  // An array of glob patterns indicating a set of files for which coverage information should be collected
-  // collectCoverageFrom: undefined,
-  collectCoverageFrom: [
-    "src/**/*.{js,jsx,ts,tsx}",
-    "!**/*.d.ts",
-    "!**/stor{y,ies}.{js,ts,jsx,tsx}",
-    "!**/*.stor{y,ies}.{js,ts,jsx,tsx}",
-    "!**/node_modules/**",
-    "!**/cypress/**",
-    "!**/.storybook/**",
-    "!**/stories/**",
-    "!**/storybook-static/**",
-    "!jest.config.js",
-    "!**/out/**",
-    "!**/dist/**",
-    "!**/public/**",
-    "!**/build/**",
-    "!**/coverage/**",
-  ],
-
-  // The directory where Jest should output its coverage files
-  coverageDirectory: "coverage-unit",
-
   // An array of regexp pattern strings used to skip coverage collection
   // coveragePathIgnorePatterns: [
   //   "/node_modules/"
@@ -61,21 +69,12 @@ module.exports = {
   // An object that configures minimum threshold enforcement for coverage results
   // coverageThreshold: undefined,
 
-  // A path to a custom dependency extractor
-  // dependencyExtractor: undefined,
-
   // Make calling deprecated APIs throw helpful error messages
   // errorOnDeprecated: false,
 
   // Force coverage collection from ignored files using an array of glob patterns
   // forceCoverageMatch: [],
 
-  // A path to a module which exports an async function that is triggered once before all test suites
-  globalSetup: "./tests/globalSetup",
-
-  // A path to a module which exports an async function that is triggered once after all test suites
-  // globalTeardown: undefined,
-
   // A set of global variables that need to be available in all test environments
   //globals: {
   //  "ts-jest": {
@@ -91,14 +90,15 @@ module.exports = {
   //   "node_modules"
   // ],
 
+  // A path to a custom dependency extractor
+  // dependencyExtractor: undefined,
+
+  // A path to a module which exports an async function that is triggered once before all test suites
+  globalSetup: "./tests/globalSetup",
+
   // An array of file extensions your modules use
   moduleFileExtensions: ["js", "json", "jsx", "ts", "tsx", "node"],
 
-  // A map from regular expressions to module names that allow to stub out resources with a single module
-  moduleNameMapper: {
-    "~/(.*)": "<rootDir>/src/$1",
-    "@vulcanjs/(.*)": "<rootDir>/packages/@vulcanjs/$1",
-  },
 
   // An array of regexp pattern strings, matched against all module paths before considered 'visible' to the module loader
   // modulePathIgnorePatterns: [],
@@ -142,9 +142,6 @@ module.exports = {
   // The paths to modules that run some code to configure or set up the testing environment before each test
   // setupFiles: [],
 
-  // A list of paths to modules that run some code to configure or set up the testing framework before each test
-  setupFilesAfterEnv: ["./tests/setupTests.js"],
-
   // A list of paths to snapshot serializer modules Jest should use for snapshot testing
   // snapshotSerializers: [],
 
@@ -157,20 +154,6 @@ module.exports = {
   // Adds a location field to test results
   // testLocationInResults: false,
 
-  // The glob patterns Jest uses to detect test files
-  // testMatch: [
-  //   "**/__tests__/**/*.[jt]s?(x)",
-  //   "**/?(*.)+(spec|test).[tj]s?(x)"
-  // ],
-
-  // An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
-  testPathIgnorePatterns: [
-    "/node_modules/",
-    "/cypress/",
-    "/storybook/",
-    "/.next/",
-    "/stories/",
-  ],
 
   // The regexp pattern or array of patterns that Jest uses to detect test files
   // testRegex: [],
@@ -187,20 +170,6 @@ module.exports = {
   // Setting this value to "fake" allows the use of fake timers for functions such as "setTimeout"
   // timers: "real",
 
-  // A map from regular expressions to paths to transformers
-  // transform: undefined,
-  transform: {
-    //"^.+\\.[jt]sx?$": "ts-jest",
-    "^.+\\.(js|jsx|ts|tsx)$": "<rootDir>/node_modules/babel-jest",
-    // MDX support
-    "^.+\\.(md|mdx)$": "jest-transformer-mdx",
-  },
-
-  // An array of regexp pattern strings that are matched against all source file paths, matched files will skip transformation
-  // transformIgnorePatterns: [
-  //   "/node_modules/"
-  // ],
-
   // An array of regexp pattern strings that are matched against all modules before the module loader will automatically return a mock for them
   // unmockedModulePathPatterns: undefined,
 
@@ -212,4 +181,55 @@ module.exports = {
 
   // Whether to use watchman for file crawling
   // watchman: true,
-};
+}
+
+module.exports = {
+  // An array of glob patterns indicating a set of files for which coverage information should be collected
+  collectCoverageFrom: [
+    "src/**/*.{js,jsx,ts,tsx}",
+    "!**/*.d.ts",
+    "!**/stor{y,ies}.{js,ts,jsx,tsx}",
+    "!**/*.stor{y,ies}.{js,ts,jsx,tsx}",
+    "!**/node_modules/**",
+    "!**/cypress/**",
+    "!**/.storybook/**",
+    "!**/stories/**",
+    "!**/storybook-static/**",
+    "!jest.config.js",
+    "!**/out/**",
+    "!**/dist/**",
+    "!**/public/**",
+    "!**/build/**",
+    "!**/coverage/**",
+  ],
+
+  // configuration for each environment (client or server)
+  projects: [
+    {
+      ...commonConfig,
+      name: 'client',
+      displayName: 'client',
+      // testEnvironment: "jsdom", // defautl already
+      // The glob patterns Jest uses to detect test files
+      testMatch: [
+        '**/__tests__/(!server)/**/*.[jt]s?(x)',
+        '**/__tests__/*.[jt]s?(x)',
+        '**/!(*.server).test.[jt]s?(x)',
+      ],
+      // A list of paths to modules that run some code to configure or set up the testing framework before each test
+      setupFilesAfterEnv: ["./tests/setupTests.js"], modulePaths: ['<rootDir>'],
+    },
+    {
+      ...commonConfig,
+      name: 'server',
+      displayName: 'server',
+      testEnvironment: 'node',
+      // The glob patterns Jest uses to detect test files
+      testMatch: [
+        '**/__tests__/server/**/*.[jt]s?(x)',
+        '**/*.server.test.[jt]s?(x)',
+      ],
+      setupFilesAfterEnv: ["./tests/setupTests.server.js"], modulePaths: ['<rootDir>'],
+    },
+  ],
+}

tests/configTests/exampleClient.test.js

@@ -0,0 +1,5 @@
+describe('Default test (collocated with code)', () => {
+    test('Default test is run in a JSDOM environment', () => {
+        expect(window).toBeDefined()
+    })
+})

tests/configTests/exampleServer.server.test.js

@@ -0,0 +1,9 @@
+describe('Server-only test (collocated with code)', () => {
+    // Since jsdom also has node definied, this test is more to be sure that server tests will run than to see that it isn't processed as a client.
+    test('server-only test is run in a Node environment', () => {
+        expect(process?.versions?.node).toBeDefined()
+    })
+    test('server-only test is NOT run in a JSDOM environment', () => {
+        expect(typeof window).toBe('undefined')
+    })
+})

tests/setupTests.server.js

@@ -0,0 +1 @@
+// Put here your code configuring or setting up server testing environment