From 09dfa97af9cd220245559f4ce6a5b012c8d99533 Mon Sep 17 00:00:00 2001
From: Matthias Kretschmann <m@kretschmann.io>
Date: Sun, 24 Sep 2023 12:49:10 +0100
Subject: [PATCH] refactor for better testability

---
 src/index.ts       | 92 ++++++++++++++++++++++++----------------------
 test/index.test.ts | 75 +++++++++++++++++++++++++++++++++++++
 2 files changed, 124 insertions(+), 43 deletions(-)
 create mode 100644 test/index.test.ts

diff --git a/src/index.ts b/src/index.ts
index 76119c2..6cc522f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -10,57 +10,63 @@ export type PluginOptions = {
   getSlug?: GetSlug
 }
 
+export type HookOptions = Parameters<
+  AstroIntegration['hooks']['astro:config:setup'] & { 0: any }
+>[0]
+
 export type Redirects = { [old: string]: string }
 
+export async function initPlugin(
+  hookOptions: HookOptions,
+  options?: PluginOptions
+) {
+  const _contentDir = options?.contentDir || 'src/pages/'
+  const _getSlug = options?.getSlug || getSlugFromFilePath
+  const _contentDirPath = path.join(process.cwd(), _contentDir)
+  const { logger, config, command, updateConfig } = hookOptions
+
+  try {
+    const markdownFiles = await getMarkdownFiles(_contentDirPath)
+    if (!markdownFiles?.length) {
+      logger.warn('No markdown files found')
+      return
+    }
+
+    const redirects = await getRedirects(
+      markdownFiles,
+      _contentDirPath,
+      _getSlug,
+      command
+    )
+    if (!redirects || !Object.keys(redirects).length) {
+      logger.warn('No redirects found in markdown files')
+      return
+    }
+
+    updateConfig({ redirects })
+
+    const redirectFilePath = path.join(
+      config.cacheDir.pathname, // Default is ./node_modules/.astro/
+      'redirect_from.json'
+    )
+    await writeJson(redirectFilePath, redirects)
+
+    logger.info(
+      `Added ${Object.keys(redirects).length} redirects to Astro config`
+    )
+  } catch (error: any) {
+    logger.error((error as Error).message)
+  }
+}
+
 export default function astroRedirectFrom(
   options?: PluginOptions
 ): AstroIntegration {
-  const _contentDir = options?.contentDir || 'src/pages/'
-  const _getSlug = options?.getSlug || getSlugFromFilePath
-  const _contentDirPath = path.join(process.cwd(), _contentDir)
-
   return {
     name: 'redirect-from',
     hooks: {
-      'astro:config:setup': async ({
-        config,
-        command,
-        updateConfig,
-        logger
-      }) => {
-        try {
-          const markdownFiles = await getMarkdownFiles(_contentDirPath)
-          if (!markdownFiles?.length) {
-            logger.warn('No markdown files found')
-            return
-          }
-
-          const redirects = await getRedirects(
-            markdownFiles,
-            _contentDirPath,
-            _getSlug,
-            command
-          )
-          if (!redirects || !Object.keys(redirects).length) {
-            logger.info('No redirects found in markdown files')
-            return
-          }
-
-          updateConfig({ redirects })
-
-          const redirectFilePath = path.join(
-            config.cacheDir.pathname, // Default is ./node_modules/.astro/
-            'redirect_from.json'
-          )
-          await writeJson(redirectFilePath, redirects)
-
-          logger.info(
-            `Added ${Object.keys(redirects).length} redirects to Astro config`
-          )
-        } catch (error: any) {
-          logger.error((error as Error).message)
-        }
-      }
+      'astro:config:setup': async (hookOptions) =>
+        await initPlugin(hookOptions, options)
     }
   }
 }
diff --git a/test/index.test.ts b/test/index.test.ts
new file mode 100644
index 0000000..e2f00e8
--- /dev/null
+++ b/test/index.test.ts
@@ -0,0 +1,75 @@
+import { describe, it, expect, vi } from 'vitest'
+import astroRedirectFrom, { initPlugin } from '../src/index'
+import * as utils from '../src/utils'
+import * as redirects from '../src/getRedirects'
+
+describe('initPlugin', () => {
+  const mockLogger = {
+    warn: vi.fn(),
+    info: vi.fn(),
+    error: vi.fn()
+  }
+
+  const hookOptionsMock = {
+    logger: mockLogger,
+    config: {
+      cacheDir: { pathname: './node_modules/.astro/' }
+    },
+    command: 'dev',
+    updateConfig: vi.fn()
+  }
+
+  it('should handle no markdown files scenario', async () => {
+    const getMarkdownFilesSpy = vi.spyOn(utils, 'getMarkdownFiles')
+    getMarkdownFilesSpy.mockResolvedValue([])
+
+    await initPlugin(hookOptionsMock as any)
+
+    expect(mockLogger.warn).toBeCalledWith('No markdown files found')
+    expect(hookOptionsMock.updateConfig).not.toBeCalled()
+  })
+
+  it('should handle no redirects found scenario', async () => {
+    const getMarkdownFilesSpy = vi.spyOn(utils, 'getMarkdownFiles')
+    getMarkdownFilesSpy.mockResolvedValue(['test.md', 'test2.md'])
+
+    const getRedirectsSpy = vi.spyOn(redirects, 'getRedirects')
+    getRedirectsSpy.mockResolvedValue({})
+
+    await initPlugin(hookOptionsMock as any)
+
+    expect(mockLogger.warn).toBeCalledWith(
+      'No redirects found in markdown files'
+    )
+    expect(hookOptionsMock.updateConfig).not.toBeCalled()
+  })
+
+  it('should handle redirects found scenario', async () => {
+    const getMarkdownFilesSpy = vi.spyOn(utils, 'getMarkdownFiles')
+    getMarkdownFilesSpy.mockResolvedValue(['test.md', 'test2.md'])
+
+    const getRedirectsSpy = vi.spyOn(redirects, 'getRedirects')
+    getRedirectsSpy.mockResolvedValue({ '/old': '/new' })
+
+    const writeJsonSpy = vi.spyOn(utils, 'writeJson')
+    writeJsonSpy.mockImplementation(() => Promise.resolve())
+
+    await initPlugin(hookOptionsMock as any)
+
+    expect(hookOptionsMock.updateConfig).toBeCalledWith({
+      redirects: { '/old': '/new' }
+    })
+    expect(mockLogger.info).toBeCalledWith('Added 1 redirects to Astro config')
+    expect(writeJsonSpy).toBeCalled()
+  })
+})
+
+describe('astroRedirectFrom', () => {
+  it('should return an AstroIntegration object', () => {
+    const result = astroRedirectFrom()
+
+    expect(result).toHaveProperty('name', 'redirect-from')
+    expect(result).toHaveProperty('hooks')
+    expect(result.hooks).toHaveProperty('astro:config:setup')
+  })
+})