feat: add codetransformer.addLimiter codemod

Author: thetutlage

src/code_transformer/main.ts

@@ -28,6 +28,7 @@ import type {
   EnvValidationNode,
   BouncerPolicyNode,
   ValidatorNode,
+  LimiterNode,
   MixinDefinition,
   ControllerMethodNode,
 } from '../types/code_transformer.ts'
@@ -672,6 +673,53 @@ export class CodeTransformer {
     await file.save()
   }
 
+  async addLimiter(definition: LimiterNode) {
+    const directories = this.getDirectories()
+    const filePath = `${directories.start}/${definition.limiterFileName}`
+
+    /**
+     * Get the limiter file URL
+     */
+    const limiterFileUrl = join(this.#cwdPath, `./${filePath}`)
+    let file = this.project.getSourceFile(limiterFileUrl)
+
+    /**
+     * Try to load the file from disk if not already in the project
+     */
+    if (!file) {
+      try {
+        file = this.project.addSourceFileAtPath(limiterFileUrl)
+      } catch {
+        // File does not exist on disk, we will create it
+      }
+    }
+
+    /**
+     * If the file does not exist, create it
+     */
+    if (!file) {
+      file = this.project.createSourceFile(limiterFileUrl, definition.contents)
+      file.formatText(this.#editorSettings)
+      await file.save()
+      return
+    }
+
+    /**
+     * Check if the export already exists
+     */
+    const existingExport = file.getVariableDeclaration(definition.exportName)
+    if (existingExport) {
+      return
+    }
+
+    /**
+     * Add the limiter to the existing file
+     */
+    file.addStatements(`\n${definition.contents}`)
+    file.formatText(this.#editorSettings)
+    await file.save()
+  }
+
   async addModelMixins(modelFileName: string, mixins: MixinDefinition[]) {
     const directories = this.getDirectories()
     const filePath = `${directories.models}/${modelFileName}`

src/types/code_transformer.ts

@@ -114,6 +114,12 @@ export type ValidatorNode = {
   contents: string
 }
 
+export type LimiterNode = {
+  limiterFileName: string
+  exportName: string
+  contents: string
+}
+
 export type MixinDefinition = {
   name: string
   args?: string[]

tests/code_transformer.spec.ts

@@ -1425,6 +1425,129 @@ test.group('Code Transformer | addValidator', (group) => {
   })
 })
 
+test.group('Code Transformer | addLimiter', (group) => {
+  group.each.setup(async ({ context }) => setupFakeAdonisproject(context.fs))
+
+  test('add limiter to a non-existing limiter file', async ({ assert, fs }) => {
+    const transformer = new CodeTransformer(fs.baseUrl)
+
+    await transformer.addLimiter({
+      exportName: 'apiLimiter',
+      limiterFileName: 'limiter.ts',
+      contents: dedent`
+      export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      `,
+    })
+
+    const file = await fs.contents('start/limiter.ts')
+    assert.snapshot(file).matchInline(`
+      "export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      "
+    `)
+  })
+
+  test('add limiter to existing limiter file with other exports', async ({ assert, fs }) => {
+    const transformer = new CodeTransformer(fs.baseUrl)
+    await fs.create(
+      'start/limiter.ts',
+      dedent`
+      export const globalLimiter = limiter.define('global', () => {
+        return limiter.allowRequests(100).every('1 minute')
+      })
+    `
+    )
+
+    await transformer.addLimiter({
+      exportName: 'apiLimiter',
+      limiterFileName: 'limiter.ts',
+      contents: dedent`
+      export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      `,
+    })
+
+    const file = await fs.contents('start/limiter.ts')
+    assert.snapshot(file).matchInline(`
+      "export const globalLimiter = limiter.define('global', () => {
+        return limiter.allowRequests(100).every('1 minute')
+      })
+
+      export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      "
+    `)
+  })
+
+  test('skip adding limiter when it already exists', async ({ assert, fs }) => {
+    const transformer = new CodeTransformer(fs.baseUrl)
+    await fs.create(
+      'start/limiter.ts',
+      dedent`
+      export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(5).every('1 minute')
+      })
+    `
+    )
+
+    await transformer.addLimiter({
+      exportName: 'apiLimiter',
+      limiterFileName: 'limiter.ts',
+      contents: dedent`
+      export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      `,
+    })
+
+    const file = await fs.contents('start/limiter.ts')
+    assert.snapshot(file).matchInline(`
+      "export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(5).every('1 minute')
+      })"
+    `)
+  })
+
+  test('use custom start directory from adonisrc.ts', async ({ assert, fs }) => {
+    await fs.create(
+      'adonisrc.ts',
+      dedent`
+      import { defineConfig } from '@adonisjs/core/app'
+
+      export default defineConfig({
+        directories: {
+          start: 'boot',
+        }
+      })`
+    )
+
+    const transformer = new CodeTransformer(fs.baseUrl)
+
+    await transformer.addLimiter({
+      exportName: 'apiLimiter',
+      limiterFileName: 'limiter.ts',
+      contents: dedent`
+      export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      `,
+    })
+
+    const file = await fs.contents('boot/limiter.ts')
+    assert.snapshot(file).matchInline(`
+      "export const apiLimiter = limiter.define('api', () => {
+        return limiter.allowRequests(10).every('1 minute')
+      })
+      "
+    `)
+  })
+})
+
 test.group('Code Transformer | addModelMixins', (group) => {
   group.each.setup(async ({ context }) => setupFakeAdonisproject(context.fs))