Read codemod target versions from workspace manifests at build time (#2419)

Author: felixweinberger

.changeset/codemod-versions-from-manifests.md

@@ -0,0 +1,5 @@
+---
+'@modelcontextprotocol/codemod': patch
+---
+
+Read the v2 package versions the codemod writes into migrated `package.json` files directly from the workspace manifests at build time, replacing the committed generated `versions.ts` (which went stale after every release and made source builds write outdated versions).

packages/codemod/package.json

@@ -41,8 +41,6 @@
     ],
     "scripts": {
         "typecheck": "tsgo -p tsconfig.json --noEmit",
-        "generate:versions": "tsx scripts/generateVersions.ts",
-        "prebuild": "pnpm run generate:versions",
         "build": "tsdown",
         "build:watch": "tsdown --watch",
         "prepack": "pnpm run build",

packages/codemod/scripts/generateVersions.ts

@@ -6,10 +6,10 @@ import { tmpdir } from 'node:os';
 import path from 'node:path';
 import { fileURLToPath, pathToFileURL } from 'node:url';
 
-import { V2_PACKAGE_VERSIONS } from '../generated/versions';
 import { getMigration } from '../migrations/index';
 import { run } from '../runner';
 import type { Diagnostic, Migration } from '../types';
+import { V2_PACKAGE_VERSIONS } from '../versions';
 
 // ---------------------------------------------------------------------------
 // Types

packages/codemod/src/bin/batchTest.ts

@@ -3,8 +3,8 @@ import path from 'node:path';
 
 import fg from 'fast-glob';
 
-import { V2_PACKAGE_VERSIONS } from '../generated/versions';
 import type { PackageJsonChange } from '../types';
+import { V2_PACKAGE_VERSIONS } from '../versions';
 import { findPackageJson } from './projectAnalyzer';
 
 const V1_PACKAGE = '@modelcontextprotocol/sdk';

packages/codemod/src/generated/versions.ts

@@ -0,0 +1,20 @@
+import clientPkg from '../../client/package.json';
+import corePkg from '../../core/package.json';
+import expressPkg from '../../middleware/express/package.json';
+import nodePkg from '../../middleware/node/package.json';
+import serverPkg from '../../server/package.json';
+import serverLegacyPkg from '../../server-legacy/package.json';
+
+/**
+ * Caret ranges for the v2 packages the codemod writes into migrated package.json
+ * files. Versions come straight from the workspace manifests — the bundler inlines
+ * them at build time — so a release bump can never leave this map stale.
+ */
+export const V2_PACKAGE_VERSIONS: Record<string, string> = {
+    '@modelcontextprotocol/client': `^${clientPkg.version}`,
+    '@modelcontextprotocol/server': `^${serverPkg.version}`,
+    '@modelcontextprotocol/node': `^${nodePkg.version}`,
+    '@modelcontextprotocol/express': `^${expressPkg.version}`,
+    '@modelcontextprotocol/server-legacy': `^${serverLegacyPkg.version}`,
+    '@modelcontextprotocol/core': `^${corePkg.version}`
+};