feat: add package.json Express v5 codemod

Author: Vinayak1337

codemods/v5-migration-recipe/README.md

@@ -4,6 +4,7 @@ This codemod migration recipe helps you update your Express.js v4 applications t
 
 Included transformations:
 
+- **Package JSON Dependencies**: Updates existing `express` and `@types/express` package entries in `package.json` for Express.js v5 migrations.
 - **Back Redirect Deprecated**: This transformation updates instances of `res.redirect('back')` and `res.location('back')` to use the recommended alternatives. Registry entry: [https://app.codemod.com/registry/@expressjs/back-redirect-deprecated](https://app.codemod.com/registry/@expressjs/back-redirect-deprecated).
 - **Explicit Request Params**: Migrates usage of the legacy API `req.param(name)` to the current recommended alternatives. Registry entry: [https://app.codemod.com/registry/@expressjs/explicit-request-params](https://app.codemod.com/registry/@expressjs/explicit-request-params).
 - **Pluralize Method Names**: Migrates deprecated singular request methods to their pluralized counterparts where applicable. Registry entry: [https://app.codemod.com/registry/@expressjs/pluralize-method-names](https://app.codemod.com/registry/@expressjs/pluralize-method-names).

codemods/v5-migration-recipe/codemod.yaml

@@ -10,6 +10,7 @@ category: migration
 
 targets:
   languages:
+    - json
     - javascript
     - typescript
 
@@ -23,4 +24,4 @@ keywords:
 
 registry:
   access: public
-  visibility: public
+  visibility: public

codemods/v5-migration-recipe/package.json

@@ -4,6 +4,9 @@
   "version": "1.0.0",
   "description": "This codemod migration recipe helps you update your Express.js v4 applications to be compatible with Express.js v5 by addressing deprecated APIs.",
   "type": "module",
+  "scripts": {
+    "test": "npx codemod jssg test -l json ./src/package-json.ts ./"
+  },
   "repository": {
     "type": "git",
     "url": "git+https://github.com/expressjs/codemod.git",

codemods/v5-migration-recipe/src/package-json.ts

@@ -0,0 +1,64 @@
+import type Json from '@codemod.com/jssg-types/src/langs/json'
+import type { Edit, SgRoot } from '@codemod.com/jssg-types/src/main'
+
+const EXPRESS_V5 = '^5.0.0'
+const EXPRESS_TYPES_V5 = '^5.0.0'
+const DEPENDENCY_SECTIONS = ['dependencies', 'devDependencies', 'peerDependencies', 'optionalDependencies'] as const
+
+type PackageJson = {
+  [key: string]: unknown
+}
+
+function isRecord(value: unknown): value is Record<string, unknown> {
+  return typeof value === 'object' && value !== null && !Array.isArray(value)
+}
+
+function updateDependency(dependencies: unknown, packageName: string, version: string): boolean {
+  if (!isRecord(dependencies)) {
+    return false
+  }
+
+  if (Object.hasOwn(dependencies, packageName) && dependencies[packageName] !== version) {
+    dependencies[packageName] = version
+    return true
+  }
+
+  return false
+}
+
+function detectIndent(source: string): string | number {
+  const match = source.match(/\n([ \t]+)"/)
+
+  return match?.[1] ?? 2
+}
+
+async function transform(root: SgRoot<Json>): Promise<string | null> {
+  const rootNode = root.root()
+  const source = rootNode.text()
+  let packageJson: PackageJson
+
+  try {
+    packageJson = JSON.parse(source) as PackageJson
+  } catch {
+    return null
+  }
+
+  let changed = false
+
+  for (const section of DEPENDENCY_SECTIONS) {
+    const dependencies = packageJson[section]
+    changed = updateDependency(dependencies, 'express', EXPRESS_V5) || changed
+    changed = updateDependency(dependencies, '@types/express', EXPRESS_TYPES_V5) || changed
+  }
+
+  if (!changed) {
+    return null
+  }
+
+  const nextSource = `${JSON.stringify(packageJson, null, detectIndent(source))}${source.endsWith('\n') ? '\n' : ''}`
+  const edits: Edit[] = [rootNode.replace(nextSource)]
+
+  return rootNode.commitEdits(edits)
+}
+
+export default transform

codemods/v5-migration-recipe/tests/expected/dependencies.json

@@ -0,0 +1,11 @@
+{
+  "name": "express-app",
+  "dependencies": {
+    "body-parser": "^1.20.3",
+    "express": "^5.0.0"
+  },
+  "devDependencies": {
+    "@types/express": "^5.0.0",
+    "typescript": "^5.7.2"
+  }
+}

codemods/v5-migration-recipe/tests/expected/dev-dependency-only.json

@@ -0,0 +1,6 @@
+{
+  "name": "dev-only",
+  "devDependencies": {
+    "express": "^5.0.0"
+  }
+}

codemods/v5-migration-recipe/tests/expected/no-express.json

@@ -0,0 +1,9 @@
+{
+  "name": "no-express",
+  "dependencies": {
+    "koa": "^2.15.3"
+  },
+  "devDependencies": {
+    "typescript": "^5.7.2"
+  }
+}

codemods/v5-migration-recipe/tests/expected/peer-and-optional.json

@@ -0,0 +1,9 @@
+{
+  "name": "express-plugin",
+  "peerDependencies": {
+    "express": "^5.0.0"
+  },
+  "optionalDependencies": {
+    "@types/express": "^5.0.0"
+  }
+}

codemods/v5-migration-recipe/tests/input/dependencies.json

@@ -0,0 +1,11 @@
+{
+  "name": "express-app",
+  "dependencies": {
+    "body-parser": "^1.20.3",
+    "express": "^4.18.2"
+  },
+  "devDependencies": {
+    "@types/express": "^4.17.21",
+    "typescript": "^5.7.2"
+  }
+}

codemods/v5-migration-recipe/tests/input/dev-dependency-only.json

@@ -0,0 +1,6 @@
+{
+  "name": "dev-only",
+  "devDependencies": {
+    "express": "~4.21.0"
+  }
+}