Support --if-present argument with bun run

[simenandre]

What is the problem this feature would solve?

When building standardized CI workflows, we set some standard commands that are typical to find in projects.
If the script doesn't exists, bun fails, which breaks those workflows if a project doesn't have that script/command.

What is the feature you are proposing to solve the problem?

We typically use pnpm run --if-present <command> on workflows today.

This will only run the command if the script is available in the package.

What alternatives have you considered?

• We can probably build some script that skips steps in our workflow based on package.json.
• Add all scripts defined in a workflow, e.g. exit 0

[simenandre]

More context: I'm adding support for Bun in our standardized GitHub Actions, which you can find a PR for here:
bjerkio/workflows#6.

As displayed in the PR above, the workaround for us, right now, is to add scripts with exit 0.

Example workflow from PNPM:
https://github.com/bjerkio/workflows/blob/main/.github/workflows/pnpm-typical.yml