Merge pull request #26130 from backstage/mob/backend-lint

repo-tools: Add backend-lint command

packages/repo-tools/cli-report.md

@@ -18,6 +18,7 @@ Commands:
   knip-reports [options] [paths...]
   package [command]
   repo [command]
+  lint [command]
   help [command]
 ```
 
@@ -60,6 +61,28 @@ Options:
   -h, --help
 ```
 
+### `backstage-repo-tools lint`
+
+```
+Usage: backstage-repo-tools lint [options] [command] [command]
+
+Options:
+  -h, --help
+
+Commands:
+  legacy-backend-exports [paths...]
+  help [command]
+```
+
+### `backstage-repo-tools lint legacy-backend-exports`
+
+```
+Usage: backstage-repo-tools lint legacy-backend-exports [options] [paths...]
+
+Options:
+  -h, --help
+```
+
 ### `backstage-repo-tools package`
 
 ```

packages/repo-tools/package.json

@@ -73,6 +73,7 @@
     "minimatch": "^9.0.0",
     "p-limit": "^3.0.2",
     "portfinder": "^1.0.32",
+    "ts-morph": "^23.0.0",
     "yaml-diff-patch": "^2.0.0"
   },
   "devDependencies": {

packages/repo-tools/src/commands/index.ts

@@ -162,6 +162,23 @@ function registerRepoCommand(program: Command) {
     );
 }
 
+function registerLintCommand(program: Command) {
+  const lintCommand = program
+    .command('lint [command]')
+    .description('Tools for linting repository.');
+  lintCommand
+    .command('legacy-backend-exports [paths...]')
+    .description(
+      'Lint backend plugin packages for legacy exports and make sure it conforms to the new export pattern',
+    )
+    .action(
+      lazy(() =>
+        import(
+          './lint-legacy-backend-exports/lint-legacy-backend-exports'
+        ).then(m => m.lint),
+      ),
+    );
+}
 export function registerCommands(program: Command) {
   program
     .command('api-reports [paths...]')
@@ -238,6 +255,7 @@ export function registerCommands(program: Command) {
 
   registerPackageCommand(program);
   registerRepoCommand(program);
+  registerLintCommand(program);
 }
 
 // Wraps an action function so that it always exits and handles errors

packages/repo-tools/src/commands/lint-legacy-backend-exports/lint-legacy-backend-exports.ts

@@ -0,0 +1,98 @@
+/*
+ * Copyright 2024 The Backstage Authors
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+import { Project } from 'ts-morph';
+import { BackstagePackageJson, PackageGraph } from '@backstage/cli-node';
+import fs from 'fs-extra';
+import { paths as cliPaths } from '../../lib/paths';
+import path from 'path';
+
+const project = new Project({
+  tsConfigFilePath: cliPaths.resolveTargetRoot('tsconfig.json'),
+});
+
+function readPackageJson(pkg: string) {
+  return JSON.parse(fs.readFileSync(path.join(pkg, 'package.json'), 'utf-8'));
+}
+
+export async function lint(paths: string[]) {
+  const pkgs = (await PackageGraph.listTargetPackages()).filter(pkg => {
+    return (
+      pkg.packageJson.backstage?.role === 'backend-plugin' ||
+      pkg.packageJson.backstage?.role === 'backend-plugin-module'
+    );
+  });
+
+  if (paths.length > 0) {
+    paths.forEach(pkg => verifyIndex(pkg));
+    return;
+  }
+  pkgs.forEach(pkg => verifyIndex(pkg.dir, pkg.packageJson));
+}
+
+function verifyIndex(pkg: string, packageJson?: BackstagePackageJson) {
+  console.log(`Verifying ${pkg}`);
+  const tsPath = path.join(pkg, 'src/index.ts');
+  const sourceFile = project.getSourceFile(tsPath);
+  if (!sourceFile) {
+    console.log(`Could not find ${tsPath}`);
+    process.exit(1);
+  }
+  const symbols = sourceFile?.getExportSymbols();
+
+  const exportCount = symbols?.length || 0;
+  if (exportCount > 1) {
+    console.log(
+      `   ⚠️ Warning: ${exportCount} exports found, ${symbols
+        .map(symbol => symbol.getName())
+        .join(', ')}`,
+    );
+  }
+
+  const createRouterExport = symbols?.find(
+    symbol => symbol.getName() === 'createRouter',
+  );
+
+  if (!sourceFile.getDefaultExportSymbol()) {
+    console.log('   ❌ Missing default export');
+  }
+  let createRouterDeprecated = undefined;
+  if (createRouterExport) {
+    createRouterDeprecated = createRouterExport
+      .getJsDocTags()
+      .find(tag => tag.getName() === 'deprecated');
+  }
+
+  if (createRouterExport) {
+    console.log('   ❌ createRouter is exported');
+    if (!createRouterDeprecated)
+      console.log('   ❌ createRouter is NOT deprecated');
+  }
+
+  const pkgJson = packageJson ?? readPackageJson(pkg);
+  if (
+    '@backstage/backend-common' in pkgJson.dependencies ||
+    '@backstage/backend-common' in pkgJson.devDependencies
+  ) {
+    console.log('   ❌ Stop depending on @backstage/backend-common');
+  }
+
+  if (
+    '@backstage/backend-tasks' in pkgJson.dependencies ||
+    '@backstage/backend-tasks' in pkgJson.devDependencies
+  ) {
+    console.log('   ❌ Stop depending on @backstage/backend-tasks');
+  }
+}

yarn.lock

@@ -7886,6 +7886,7 @@ __metadata:
     minimatch: ^9.0.0
     p-limit: ^3.0.2
     portfinder: ^1.0.32
+    ts-morph: ^23.0.0
     yaml-diff-patch: ^2.0.0
   peerDependencies:
     "@microsoft/api-extractor-model": "*"
@@ -17089,6 +17090,18 @@ __metadata:
   languageName: node
   linkType: hard
 
+"@ts-morph/common@npm:~0.24.0":
+  version: 0.24.0
+  resolution: "@ts-morph/common@npm:0.24.0"
+  dependencies:
+    fast-glob: ^3.3.2
+    minimatch: ^9.0.4
+    mkdirp: ^3.0.1
+    path-browserify: ^1.0.1
+  checksum: 793bc8a47c93ab55c6c036f94480d3b0e948661aef4bb7dbc29279b1dda2fc4fce809a88e221537867a313541842e12d1ecbd32b4769688abe1303807ec09db6
+  languageName: node
+  linkType: hard
+
 "@tsconfig/node10@npm:^1.0.7":
   version: 1.0.9
   resolution: "@tsconfig/node10@npm:1.0.9"
@@ -34347,7 +34360,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"minimatch@npm:^9.0.0, minimatch@npm:^9.0.1, minimatch@npm:^9.0.3":
+"minimatch@npm:^9.0.0, minimatch@npm:^9.0.1, minimatch@npm:^9.0.3, minimatch@npm:^9.0.4":
   version: 9.0.5
   resolution: "minimatch@npm:9.0.5"
   dependencies:
@@ -42881,6 +42894,16 @@ __metadata:
   languageName: node
   linkType: hard
 
+"ts-morph@npm:^23.0.0":
+  version: 23.0.0
+  resolution: "ts-morph@npm:23.0.0"
+  dependencies:
+    "@ts-morph/common": ~0.24.0
+    code-block-writer: ^13.0.1
+  checksum: 3282eb0f8bd4577770874736c3259b97501da9a86137160b5d68f106b7848ea7b1fbccf9e198a3d930ec40c993e9951d4bfae31e2562dac8f3de0d7bb0e23615
+  languageName: node
+  linkType: hard
+
 "ts-node@npm:^10.9.1":
   version: 10.9.2
   resolution: "ts-node@npm:10.9.2"