Branch and Path Filters

paths, paths-ignore, branches

Filters keep workflows from running unnecessarily: branches limits which branches trigger, paths runs only when matching files change, and paths-ignore skips changes that only touch matching files (documentation, for example). Patterns support *, ** and ! negation, evaluated in order so later patterns override earlier ones. Beware: if a workflow is a required status check but is skipped by a path filter, the pull request may wait forever for it; configure required checks with that in mind.

Which changes trigger a path-filtered workflow? run

I ran this with Python 3. It is a simplified model of GitHub Actions behaviour for learning, not GitHub's implementation. With paths [src/, package.json, !/*.md], a source change and a package.json change run the workflow; documentation-only changes, including a Markdown file inside src/, are skipped.

from fnmatch import fnmatch
filters = ["src/**", "package.json", "!**/*.md"]       # on: push: paths: [...]
def matches(path):
    included = False
    for f in filters:                                  # later patterns override earlier ones
        neg = f.startswith("!")
        pat = f[1:] if neg else f
        if fnmatch(path, pat.replace("**/", "*").replace("/**", "/*")):
            included = not neg
    return included
for changed in [["src/app.ts"], ["docs/guide.md"], ["src/README.md"], ["package.json", "README.md"]]:
    print(changed, "->", "workflow runs" if any(matches(p) for p in changed) else "skipped")

Output:

['src/app.ts'] -> workflow runs
['docs/guide.md'] -> skipped
['src/README.md'] -> skipped
['package.json', 'README.md'] -> workflow runs

Mind required checks

Path-filtered workflows that are required checks can block merges when skipped; use a small always-running gate job or conditional logic instead.

त्वरित जाँच: With paths [src/**, !**/*.md], does changing only src/README.md trigger the workflow?

• Yes, because it is under src/
• No, the later negation excludes Markdown files
• Only on Mondays
• Only for forks