feat: add addPolicy codemod

Author: thetutlage

README.md

@@ -390,6 +390,36 @@ export const plugins: Config['plugins'] = [
 ]
 ```
 
+### addPolicy
+Register AdonisJS bouncer policy to the list of `policies` object exported from the `app/policies/main.ts` file.
+
+> [!IMPORTANT]
+> This codemod expects the `app/policies/main.ts` file to exist and must export a `policies` object from it.
+
+```ts
+const transformer = new CodeTransformer(appRoot)
+
+try {
+  await transformer.addPolicy([
+    {
+      name: 'PostPolicy',
+      path: '#policies/post_policy'
+    }
+  ])
+} catch (error) {
+  console.error('Unable to register policy')
+  console.error(error)
+}
+```
+
+Output
+
+```ts
+export const policies = {
+  UserPolicy: () => import('#policies/post_policy')
+}
+```
+
 ## Contributing
 One of the primary goals of AdonisJS is to have a vibrant community of users and contributors who believe in the framework's principles.
 

src/code_transformer/main.ts

@@ -21,7 +21,7 @@ import {
 } from 'ts-morph'
 
 import { RcFileTransformer } from './rc_file_transformer.js'
-import type { MiddlewareNode, EnvValidationNode } from '../types.js'
+import type { MiddlewareNode, EnvValidationNode, BouncerPolicyNode } from '../types.js'
 
 /**
  * This class is responsible for updating
@@ -139,6 +139,25 @@ export class CodeTransformer {
     }
   }
 
+  /**
+   * Add a policy to the list of pre-registered policy
+   */
+  #addToPoliciesList(file: SourceFile, policyEntry: BouncerPolicyNode) {
+    const policiesObject = file
+      .getVariableDeclarationOrThrow('policies')
+      .getInitializerIfKindOrThrow(SyntaxKind.ObjectLiteralExpression)
+
+    /**
+     * Only define policy when one with the existing name does not
+     * exist.
+     */
+    const existingProperty = policiesObject.getProperty(policyEntry.name)
+    if (!existingProperty) {
+      const policy = `${policyEntry.name}: () => import('${policyEntry.path}')`
+      policiesObject!.insertProperty(0, policy)
+    }
+  }
+
   /**
    * Write a leading comment
    */
@@ -338,4 +357,26 @@ export class CodeTransformer {
     file.formatText(this.#editorSettings)
     await file.save()
   }
+
+  /**
+   * Adds a policy to the list of `policies` object configured
+   * inside the `app/policies/main.ts` file.
+   */
+  async addPolicies(policies: BouncerPolicyNode[]) {
+    /**
+     * Get the `app/policies/main.ts` source file
+     */
+    const kernelUrl = fileURLToPath(new URL('./app/policies/main.ts', this.#cwd))
+    const file = this.#project.getSourceFileOrThrow(kernelUrl)
+
+    /**
+     * Process each middleware entry
+     */
+    for (const policy of policies) {
+      this.#addToPoliciesList(file, policy)
+    }
+
+    file.formatText(this.#editorSettings)
+    await file.save()
+  }
 }

src/types.ts

@@ -238,6 +238,21 @@ export type MiddlewareNode = {
   position?: 'before' | 'after'
 }
 
+/**
+ * Policy node to be added to the list of policies.
+ */
+export type BouncerPolicyNode = {
+  /**
+   * Policy name
+   */
+  name: string
+
+  /**
+   * Policy import path
+   */
+  path: string
+}
+
 /**
  * Defines the structure of an environment variable validation
  * definition

tests/code_transformer.spec.ts

@@ -702,3 +702,80 @@ test.group('Code transformer | addJapaPlugin', (group) => {
     `)
   })
 })
+
+test.group('Code transformer | addPolicies', (group) => {
+  group.each.setup(async ({ context }) => setupFakeAdonisproject(context.fs))
+
+  test('add policies to polices/main.ts file', async ({ assert, fs }) => {
+    await fs.create('app/policies/main.ts', `export const policies = {}`)
+
+    const transformer = new CodeTransformer(fs.baseUrl)
+
+    await transformer.addPolicies([
+      {
+        name: 'PostPolicy',
+        path: '#policies/post_policy',
+      },
+      {
+        name: 'UserPolicy',
+        path: '#policies/user_policy',
+      },
+    ])
+
+    const file = await fs.contents('app/policies/main.ts')
+    assert.snapshot(file).matchInline(`
+      "export const policies = {
+        UserPolicy: () => import('#policies/user_policy'),
+        PostPolicy: () => import('#policies/post_policy')
+      }
+      "
+    `)
+  })
+
+  test('throw error when policies/main.ts file is missing', async ({ fs }) => {
+    const transformer = new CodeTransformer(fs.baseUrl)
+
+    await transformer.addPolicies([
+      {
+        name: 'PostPolicy',
+        path: '#policies/post_policy',
+      },
+      {
+        name: 'UserPolicy',
+        path: '#policies/user_policy',
+      },
+    ])
+  }).throws(/Could not find source file in project at the provided path:/)
+
+  test('throw error when policies object is not defined', async ({ fs }) => {
+    await fs.create('app/policies/main.ts', `export const foo = {}`)
+    const transformer = new CodeTransformer(fs.baseUrl)
+
+    await transformer.addPolicies([
+      {
+        name: 'PostPolicy',
+        path: '#policies/post_policy',
+      },
+      {
+        name: 'UserPolicy',
+        path: '#policies/user_policy',
+      },
+    ])
+  }).throws(`Expected to find variable declaration named 'policies'.`)
+
+  test('throw error when policies declaration is not an object', async ({ fs }) => {
+    await fs.create('app/policies/main.ts', `export const policies = []`)
+    const transformer = new CodeTransformer(fs.baseUrl)
+
+    await transformer.addPolicies([
+      {
+        name: 'PostPolicy',
+        path: '#policies/post_policy',
+      },
+      {
+        name: 'UserPolicy',
+        path: '#policies/user_policy',
+      },
+    ])
+  }).throws(/Expected to find an initializer of kind \'ObjectLiteralExpression\'./)
+})