feat(ci): add parallel option

Author: matejchalk

packages/ci/README.md

@@ -97,6 +97,7 @@ Optionally, you can override default options for further customization:
 | Property           | Type                      | Default                          | Description                                                                                                                                              |
 | :----------------- | :------------------------ | :------------------------------- | :------------------------------------------------------------------------------------------------------------------------------------------------------- |
 | `monorepo`         | `boolean \| MonorepoTool` | `false`                          | Enables [monorepo mode](#monorepo-mode)                                                                                                                  |
+| `parallel`         | `boolean \| number`       | `false`                          | Enables parallel execution in [monorepo mode](#monorepo-mode)                                                                                            |
 | `projects`         | `string[] \| null`        | `null`                           | Custom projects configuration for [monorepo mode](#monorepo-mode)                                                                                        |
 | `task`             | `string`                  | `'code-pushup'`                  | Name of command to run Code PushUp per project in [monorepo mode](#monorepo-mode)                                                                        |
 | `nxProjectsFilter` | `string \| string[]`      | `'--with-target={task}'`         | Arguments passed to [`nx show projects`](https://nx.dev/nx-api/nx/documents/show#projects), only relevant for Nx in [monorepo mode](#monorepo-mode) [^2] |
@@ -193,6 +194,27 @@ await runInCI(refs, api, {
 });
 ```
 
+### Parallel tasks
+
+By default, tasks are run sequentially for each project in the monorepo.
+The `parallel` option enables parallel execution for tools which support it (Nx, Turborepo, PNPM, Yarn 2+).
+
+```ts
+await runInCI(refs, api, {
+  monorepo: true,
+  parallel: true,
+});
+```
+
+The maximum number of concurrent tasks can be set by passing in a number instead of a boolean:
+
+```ts
+await runInCI(refs, api, {
+  monorepo: true,
+  parallel: 3,
+});
+```
+
 ### Monorepo result
 
 In monorepo mode, the resolved object includes the merged diff at the top-level, as well as a list of projects.

packages/ci/src/lib/constants.ts

@@ -2,6 +2,7 @@ import type { Settings } from './models.js';
 
 export const DEFAULT_SETTINGS: Settings = {
   monorepo: false,
+  parallel: false, // TODO: default to true once battle-tested?
   projects: null,
   task: 'code-pushup',
   bin: 'npx --no-install code-pushup',

packages/ci/src/lib/models.ts

@@ -8,6 +8,7 @@ import type { MonorepoTool } from './monorepo/index.js';
  */
 export type Options = {
   monorepo?: boolean | MonorepoTool;
+  parallel?: boolean | number;
   projects?: string[] | null;
   task?: string;
   nxProjectsFilter?: string | string[];

packages/ci/src/lib/monorepo/list-projects.ts

@@ -86,7 +86,7 @@ function createMonorepoHandlerOptions(
   return {
     task: settings.task,
     cwd: settings.directory,
-    parallel: false, // TODO: add to settings
+    parallel: settings.parallel,
     nxProjectsFilter: settings.nxProjectsFilter,
     ...(!settings.silent && {
       observer: {