cli: added initial build-cache command

packages/cli/src/commands/build-cache/index.ts

@@ -0,0 +1,22 @@
+/*
+ * 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.
+ */
+
+/*
+ * The build-cache command is used to make builds a no-op if there are no changes to the package.
+ * It supports both local development where the output directory remains intact, as well as CI
+ * where the output directory is stored in a separate cache dir.
+ */
+export default async () => {};

packages/cli/src/index.ts

@@ -19,6 +19,7 @@ import chalk from 'chalk';
 import fs from 'fs';
 import createPluginCommand from './commands/create-plugin/createPlugin';
 import watch from './commands/watch-deps';
+import buildCache from './commands/build-cache';
 import lintCommand from './commands/lint';
 import testCommand from './commands/testCommand';
 import appBuild from './commands/app/build';
@@ -76,6 +77,23 @@ const main = (argv: string[]) => {
     .description('Watch all dependencies while running another command')
     .action(actionHandler(watch));
 
+  program
+    .command('build-cache')
+    .description('Wrap build command with a cache')
+    .option(
+      '--input <dirs>',
+      'List of input directories that invalidate the cache [.]',
+      (value, acc) => acc.concat(value),
+      [],
+    )
+    .option('--output <dir>', 'Output directory to cache', 'dist')
+    .option(
+      '--cache-dir <dir>',
+      'Cache dir',
+      '<repoRoot>/node_modules/.cache/backstage-builds',
+    )
+    .action(actionHandler(buildCache));
+
   program.on('command:*', () => {
     console.log();
     console.log(