add unit test cases

.babelrc

@@ -1,3 +0,0 @@
-{
-  "presets": [["@babel/env"]]
-}

.eslintrc

@@ -10,6 +10,7 @@
   "env": {
     "browser": true,
     "node": true,
-    "es2020": true
+    "es2020": true,
+    "jest": true
   }
 }

.github/workflows/ci.yml

@@ -25,11 +25,27 @@ jobs:
       - uses: actions/setup-node@v3
         with:
           node-version: ${{ matrix.node }}
+          cache: npm
 
       - run: npm ci
       - run: npm test
       - run: npm run build
 
+  coverage:
+    if: ${{ github.actor != 'dependabot[bot]' }}
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+      - uses: actions/setup-node@v3
+        with:
+          cache: npm
+      - run: npm ci
+      - uses: paambaati/codeclimate-action@v5.0.0
+        env:
+          CC_TEST_REPORTER_ID: ${{ secrets.CC_TEST_REPORTER_ID }}
+        with:
+          coverageCommand: npm test
+
   publish:
     needs: test
     if: success() && startsWith(github.ref, 'refs/tags')

.gitignore

@@ -1,2 +1,3 @@
 node_modules
 /*.js
+coverage

README.md

@@ -5,6 +5,7 @@
 [![npm package](https://img.shields.io/npm/v/gatsby-redirect-from.svg)](https://www.npmjs.com/package/gatsby-redirect-from)
 [![Build Status](https://github.com/kremalicious/gatsby-redirect-from/workflows/CI/badge.svg)](https://github.com/kremalicious/gatsby-redirect-from/actions)
 [![Maintainability](https://api.codeclimate.com/v1/badges/9643b2a038a7d338a73a/maintainability)](https://codeclimate.com/github/kremalicious/gatsby-redirect-from/maintainability)
+[![Test Coverage](https://api.codeclimate.com/v1/badges/9643b2a038a7d338a73a/test_coverage)](https://codeclimate.com/github/kremalicious/gatsby-redirect-from/test_coverage)
 
 > 🎯 Set redirect urls in your YAML frontmatter within your [Gatsby](https://www.gatsbyjs.org) site's Markdown files. Mimics the behavior of [jekyll-redirect-from](https://github.com/jekyll/jekyll-redirect-from).
 > https://kremalicious.com/gatsby-redirect-from/
@@ -65,7 +66,6 @@ redirect_from:
   - /2008/04/aperture-file-types/
   # note: trailing slashes are required
 ---
-
 ```
 
 ## [Documentation](https://kremalicious.com/gatsby-redirect-from/)

babel.config.json

@@ -0,0 +1,3 @@
+{
+  "presets": ["@babel/preset-env"]
+}

package.json

@@ -7,10 +7,11 @@
   "license": "MIT",
   "main": "index.js",
   "scripts": {
-    "build": "cross-env NODE_ENV=production babel src --out-dir . --ignore __tests__",
-    "start": "babel -w src --out-dir . --ignore __tests__",
-    "test": "eslint src/**/*.js",
-    "format": "prettier --write 'src/**/*.{js,jsx}'",
+    "build": "cross-env NODE_ENV=production babel src --out-dir .",
+    "start": "babel -w src --out-dir .",
+    "test": "npm run lint && jest --coverage",
+    "lint": "eslint ./{src,test}/**/*.js",
+    "format": "prettier --write '{src,test}/**/*.{js,jsx}'",
     "release": "release-it --non-interactive",
     "changelog": "auto-changelog -p",
     "prepublishOnly": "npm run build"
@@ -21,13 +22,14 @@
   "devDependencies": {
     "@babel/cli": "^7.23.0",
     "@babel/core": "^7.23.0",
-    "@babel/helper-define-map": "^7.18.6",
     "@babel/preset-env": "^7.22.20",
     "auto-changelog": "^2.4.0",
     "chalk": "^5.3.0",
     "cross-env": "^7.0.3",
     "eslint": "^8.50.0",
     "eslint-config-prettier": "^9.0.0",
+    "jest": "^29.7.0",
+    "jest-environment-jsdom": "^29.7.0",
     "prettier": "^3.0.3",
     "release-it": "^16.2.1"
   },
@@ -38,6 +40,14 @@
   "engines": {
     "node": ">=18"
   },
+  "jest": {
+    "transform": {
+      "^.+\\.[t|j]sx?$": "babel-jest"
+    },
+    "transformIgnorePatterns": [
+      "node_modules/(?!chalk/.*)"
+    ]
+  },
   "repository": "github:kremalicious/gatsby-redirect-from",
   "bugs": {
     "url": "https://github.com/kremalicious/gatsby-redirect-from/issues"

src/gatsby-node.js

@@ -30,6 +30,7 @@ export function createPages({ graphql, actions }, pluginOptions) {
         if (result.errors) {
           console.log(result.errors) // eslint-disable-line no-console
           reject(result.errors)
+          return
         }
 
         const allPosts = result.data.q.edges

test/gatsby-node.test.js

@@ -0,0 +1,98 @@
+/**
+ * @jest-environment jsdom
+ */
+import { graphql } from 'gatsby'
+import { createPages } from '../src/gatsby-node.js'
+
+jest.mock('gatsby', () => ({
+  graphql: jest.fn(),
+  actions: { createRedirect: jest.fn() }
+}))
+
+describe('createPages', () => {
+  let pluginOptions
+  let actions
+  let consoleLogSpy
+
+  beforeEach(() => {
+    actions = { createRedirect: jest.fn() }
+    pluginOptions = { query: 'allMarkdownRemark' }
+    consoleLogSpy = jest.spyOn(console, 'log').mockImplementation(() => {})
+  })
+
+  afterEach(() => {
+    jest.resetAllMocks()
+    consoleLogSpy.mockRestore()
+  })
+
+  it('should create redirects correctly', async () => {
+    graphql.mockReturnValueOnce(
+      Promise.resolve({
+        data: {
+          q: {
+            edges: [
+              {
+                node: {
+                  fields: { slug: '/post-1/' },
+                  frontmatter: { redirect_from: ['/old-url-1', '/old-url-2'] }
+                }
+              }
+            ]
+          }
+        }
+      })
+    )
+
+    await createPages({ graphql, actions }, pluginOptions)
+
+    expect(actions.createRedirect).toHaveBeenCalledTimes(2)
+    expect(actions.createRedirect).toHaveBeenCalledWith({
+      fromPath: '/old-url-1',
+      toPath: '/post-1/',
+      isPermanent: true,
+      redirectInBrowser: true
+    })
+    expect(actions.createRedirect).toHaveBeenCalledWith({
+      fromPath: '/old-url-2',
+      toPath: '/post-1/',
+      isPermanent: true,
+      redirectInBrowser: true
+    })
+  })
+
+  it('should use pluginOptions.query when defined', async () => {
+    const customQuery = 'someCustomQuery'
+    pluginOptions.query = customQuery
+
+    graphql.mockImplementation((queryString) => {
+      expect(queryString).toContain(customQuery)
+      return Promise.resolve({ data: { q: { edges: [] } } })
+    })
+
+    await createPages({ graphql, actions }, pluginOptions)
+  })
+
+  it('should default to allMarkdownRemark when pluginOptions.query is undefined', async () => {
+    pluginOptions.query = undefined
+
+    graphql.mockImplementation((queryString) => {
+      expect(queryString).toContain('allMarkdownRemark')
+      return Promise.resolve({ data: { q: { edges: [] } } })
+    })
+
+    await createPages({ graphql, actions }, pluginOptions)
+  })
+
+  it('should log and reject errors when the GraphQL query fails', async () => {
+    graphql.mockReturnValueOnce(
+      Promise.resolve({ errors: [{ message: 'GraphQL error' }] })
+    )
+
+    try {
+      await createPages({ graphql, actions }, pluginOptions)
+    } catch (error) {
+      expect(console.log).toHaveBeenCalledWith([{ message: 'GraphQL error' }])
+      expect(error).toEqual([{ message: 'GraphQL error' }])
+    }
+  })
+})