feat: graph clean command (#1363)

Author: saihaj

.changeset/seven-kiwis-know.md

@@ -0,0 +1,5 @@
+---
+'@graphprotocol/graph-cli': minor
+---
+
+add `graph clean` command to delete generated artifacts

packages/cli/src/commands/clean.ts

@@ -0,0 +1,39 @@
+import { Command, Flags } from '@oclif/core';
+import { print, filesystem } from 'gluegun';
+
+export default class CleanCommand extends Command {
+  static description = 'Clean the cache and generated files.';
+
+  static flags = {
+    help: Flags.help({
+      char: 'h',
+    }),
+    'codegen-dir': Flags.directory({
+      summary: 'Directory where the "graph codegen" code is stored.',
+      default: 'generated/',
+    }),
+    'build-dir': Flags.directory({
+      summary: 'Directory where the "graph build" code is stored.',
+      default: 'build/',
+    }),
+  };
+
+  async run() {
+    const {
+      flags: { 'codegen-dir': codegenDir, 'build-dir': buildDir },
+    } = await this.parse(CleanCommand);
+    const spinner = print.spin(`Cleaning cache and generated files`);
+
+    spinner.start();
+    try {
+      await filesystem.removeAsync(codegenDir);
+      await filesystem.removeAsync(buildDir);
+      spinner.succeed();
+      print.success('Cache and generated files cleaned');
+    } catch (e) {
+      spinner.fail('Failed to clean cache and generated files');
+    } finally {
+      spinner.stop();
+    }
+  }
+}