test: Re-work tests to use Jest and not mockery and mock-fs (#119)

* fix: replace mocha with jest

- allows removal of mockery, mock-fs
- should improve speed of test runs
- separates out integration-tests to run serially, and avoid impacts when working with real files in tmp dir

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* build: enable tests on node lts and latest

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* chore: remove cli.js from coverage report

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* Update .github/workflows/ci.yaml

* chore: extract eslint and jest configs

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* chore: don't build vs latest

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* fix: rename "mockers" to "jest-mocks"

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* chore: why is invalid-config test flaky

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

* fix: use different temp directories for each integration test

- And extract functions with WYSIWG naming

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>

---------

Signed-off-by: Tim Knight <tim.knight1@engineering.digital.dwp.gov.uk>
Co-authored-by: Timothy Jones <timothy.l.jones@gmail.com>

Author: TimKnight-DWP

.eslintrc

@@ -1,14 +1,49 @@
 {
-  "extends": ["prettier", "eslint:recommended", "plugin:mocha/recommended"],
-  "env": { "node": true, "es6": true },
-  "parserOptions": { "ecmaVersion": 2023 },
-  "plugins": ["mocha", "@fintechstudios/eslint-plugin-chai-as-promised"],
+  "extends": [
+    "prettier",
+    "eslint:recommended"
+  ],
+  "env": {
+    "node": true,
+    "es6": true
+  },
+  "overrides": [
+    {
+      "env": {
+        "node": true,
+        "es6": true,
+        "jest/globals": true
+      },
+      "files": [
+        "test/**"
+      ],
+      "plugins": [
+        "jest"
+      ],
+      "extends": [
+        "prettier",
+        "eslint:recommended",
+        "plugin:jest/recommended"
+      ],
+      "rules": {
+        "jest/prefer-expect-assertions": "off",
+        "jest/expect-expect": "off"
+      }
+    }
+  ],
+  "parserOptions": {
+    "ecmaVersion": 2023
+  },
+  "plugins": [
+    "jest"
+  ],
   "rules": {
     "no-var": "error",
-    "no-unused-vars": ["error", { "argsIgnorePattern": "_.*" }],
-    "mocha/max-top-level-suites": "off",
-    "mocha/no-setup-in-describe": "off",
-    "@fintechstudios/chai-as-promised/no-unhandled-promises": "error",
-    "@fintechstudios/chai-as-promised/no-await-in-condition": "error"
+    "no-unused-vars": [
+      "error",
+      {
+        "argsIgnorePattern": "_.*"
+      }
+    ]
   }
 }

.github/workflows/ci.yaml

@@ -10,8 +10,16 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        node: [18, 20.4]
-        os: [ubuntu-latest, windows-latest]
+        node: [
+          18,
+          20.4, # Known good version of 20 which ran the previous Mocha and mock-fs based tests. If you go back to re-run those, tests Node 20.4 is the last version mock-fs worked with
+          20,
+          lts/*
+        ]
+        os: [
+          ubuntu-latest,
+          windows-latest
+        ]
     env:
         OS: ${{ matrix.os }}
         NODE_VERSION: ${{ matrix.node }}
@@ -26,7 +34,6 @@ jobs:
       - run: node --version
       - run: npm install --engine-strict
       - run: npm test
-      - run: npm run coverage
       - name: Codecov
         uses: codecov/codecov-action@v3
         with:

.gitignore

@@ -14,3 +14,7 @@ npm-debug.log
 
 # coverage
 coverage
+
+# temp dirs
+*-temp
+tmp

jest.config.js

@@ -0,0 +1,28 @@
+const config = {
+  collectCoverage: true,
+  collectCoverageFrom: [
+    '**/*.{js,jsx,ts}',
+    '!**/node_modules/**',
+    '!**/tmp/**',
+    '!**/test/**',
+    '!**/coverage/**',
+    '!**/bin/**',
+  ],
+  coverageReporters: ['lcov', 'text'],
+  projects: [
+    {
+      displayName: 'Unit Test',
+      testMatch: ['**/test/*.spec.js'],
+    },
+    {
+      displayName: 'Integration Test',
+      runner: 'jest-serial-runner',
+      testMatch: ['**/test/*.integration-test.js'],
+    },
+  ],
+  silent: true, // Suppresses runtime console logs during test runs
+  testTimeout: 30000,
+  verbose: true, // Prints test describe/it names into console during test runs
+};
+
+module.exports = config;