cli: add --since flag for repo lint command

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

packages/cli/src/commands/index.ts

@@ -51,6 +51,10 @@ export function registerRepoCommand(program: CommanderStatic) {
       'Lint report output format',
       'eslint-formatter-friendly',
     )
+    .option(
+      '--since <ref>',
+      'Only lint packages that changed since the specified ref',
+    )
     .option('--fix', 'Attempt to automatically fix violations')
     .action(lazy(() => import('./repo/lint').then(m => m.command)));
 }

packages/cli/src/commands/repo/lint.ts

@@ -22,7 +22,12 @@ import { runWorkerQueueThreads } from '../../lib/parallel';
 import { paths } from '../../lib/paths';
 
 export async function command(cmd: Command): Promise<void> {
-  const packages = await PackageGraph.listTargetPackages();
+  let packages = await PackageGraph.listTargetPackages();
+
+  if (cmd.since) {
+    const graph = PackageGraph.fromPackages(packages);
+    packages = await graph.listChangedPackages({ ref: cmd.since });
+  }
 
   // This formatter uses the cwd to format file paths, so let's have that happen from the root instead
   if (cmd.format === 'eslint-formatter-friendly') {