codemods: add codemod runner with shell transform

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>

packages/codemods/src/action.ts

@@ -0,0 +1,72 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 { relative as relativePath } from 'path';
+import { spawn } from 'child_process';
+import { Command } from 'commander';
+import { findPaths } from '@backstage/cli-common';
+import { ExitCodeError } from './errors';
+
+// eslint-disable-next-line no-restricted-syntax
+const paths = findPaths(__dirname);
+
+export function createCodemodAction(name: string) {
+  return async (_: unknown, cmd: Command) => {
+    const transformPath = relativePath(
+      process.cwd(),
+      paths.resolveOwn('transforms', `${name}.js`),
+    );
+
+    const args = [
+      '--parser=tsx',
+      '--extensions=tsx,js,ts,tsx',
+      '--transform',
+      transformPath,
+      '--ignore-pattern=**/node_modules/**',
+      ...cmd.args,
+    ];
+
+    console.log(`Running jscodeshift with these arguments: ${args.join(' ')}`);
+
+    const jscodeshiftScript = require.resolve('.bin/jscodeshift');
+    const child = spawn(process.argv0, [jscodeshiftScript, ...args], {
+      stdio: 'inherit',
+      shell: true,
+      env: {
+        ...process.env,
+        FORCE_COLOR: 'true',
+      },
+    });
+
+    if (typeof child.exitCode === 'number') {
+      if (child.exitCode) {
+        throw new ExitCodeError(child.exitCode, name);
+      }
+      return;
+    }
+
+    await new Promise<void>((resolve, reject) => {
+      child.once('error', error => reject(error));
+      child.once('exit', code => {
+        if (code) {
+          reject(new ExitCodeError(code, name));
+        } else {
+          resolve();
+        }
+      });
+    });
+  };
+}

packages/codemods/src/codemods.ts

@@ -0,0 +1,28 @@
+/*
+ * Copyright 2021 Spotify AB
+ *
+ * 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.
+ */
+
+export interface Codemod {
+  name: string;
+  description: string;
+}
+
+export const codemods: Codemod[] = [
+  {
+    name: 'core-imports',
+    description:
+      'Updates @backstage/core imports to use @backstage/core-* imports instead.',
+  },
+];

packages/codemods/src/errors.ts

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2020 Spotify AB
+ *
+ * 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 chalk from 'chalk';
+
+export class CustomError extends Error {
+  get name(): string {
+    return this.constructor.name;
+  }
+}
+
+export class ExitCodeError extends CustomError {
+  readonly code: number;
+
+  constructor(code: number, command?: string) {
+    if (command) {
+      super(`Command '${command}' exited with code ${code}`);
+    } else {
+      super(`Child exited with code ${code}`);
+    }
+    this.code = code;
+  }
+}
+
+export function exitWithError(error: Error): never {
+  if (error instanceof ExitCodeError) {
+    process.stderr.write(`\n${chalk.red(error.message)}\n\n`);
+    process.exit(error.code);
+  } else {
+    process.stderr.write(`\n${chalk.red(`${error}`)}\n\n`);
+    process.exit(1);
+  }
+}

packages/codemods/src/index.ts

@@ -14,30 +14,19 @@
  * limitations under the License.
  */
 
-import program, { Command } from 'commander';
+import program from 'commander';
 import chalk from 'chalk';
+import { codemods } from './codemods';
+import { exitWithError } from './errors';
+import { createCodemodAction } from './action';
 import { version } from '../package.json';
 
-const codemods = [
-  {
-    name: 'core-imports',
-    description:
-      'Updates @backstage/core imports to use @backstage/core-* imports instead.',
-  },
-];
-
-function createCodemodAction(name: string) {
-  return (cmd: Command) => {
-    console.log(`Fake codemod ${cmd} ${name}`);
-  };
-}
-
 async function main(argv: string[]) {
   program.name('backstage-codemods').version(version);
 
   for (const codemod of codemods) {
     program
-      .command(codemod.name)
+      .command(`${codemod.name} <target-dir>`)
       .description(codemod.description)
       .option('-d, --dry', 'Dry run, no changes written to files')
       .action(createCodemodAction(codemod.name));
@@ -54,16 +43,6 @@ async function main(argv: string[]) {
   program.parse(argv);
 }
 
-function exitWithError(err: Error & { code?: unknown }) {
-  process.stdout.write(`${err.name}: ${err.stack || err.message}\n`);
-
-  if (typeof err.code === 'number') {
-    process.exit(err.code);
-  } else {
-    process.exit(1);
-  }
-}
-
 process.on('unhandledRejection', (rejection: unknown) => {
   if (rejection instanceof Error) {
     exitWithError(rejection);