Online Tool Store
· 3 min read
How to Test Glob Patterns
Heshan Fernando
Co-founder & COO
You wrote a glob pattern and now you just want to know what it matches. The pattern might work in one folder and fail in another, or it may exclude a file you thought was included.
A glob pattern tester saves you from guessing. It lets you compare a pattern against real paths and see exactly which ones match before you paste it into a config file.
What glob testing actually involves
Glob patterns are shorthand for matching file paths with wildcards. They are common in build tools, scripts, and file filters.
The hard part is not the syntax by itself. It is remembering how *, **, and exclusions behave in real directory structures.
Why people get stuck here
*and**are easy to mix up. They behave differently in nested paths.- Excludes can override matches. One negative pattern can change the result completely.
- Path depth matters. A pattern that works in one folder may miss nested files.
- Config files give little feedback. You often only find out after something breaks.
What a good glob test looks like
Real paths are included
Testing against actual file paths is more useful than staring at syntax alone.
Matches and misses are obvious
You should be able to see what the pattern includes and excludes right away.
Explanations are practical
If a pattern fails, the reason should be easy to understand.
| Pattern Type | Typical Use | Watch Out |
|---|---|---|
*.js | Match files in one folder | Does not reach nested folders |
**/*.js | Match files recursively | Easy to overmatch |
!**/*.test.js | Exclude test files | Order can matter |
Common mistakes to avoid
- Using a single
*when you needed a recursive match. - Forgetting that exclusions can remove files you expected to keep.
- Testing only one path and assuming the rest behave the same.
- Putting the pattern into a config file before checking it.
- Mixing path separators without considering the environment.
How to do it with Glob Pattern Tester
Online Tool Store’s Glob Pattern Tester shows how your pattern behaves against candidate paths.
- Open the tester.
- Paste the glob pattern you want to check.
- Add a few real file paths from your project.
- Review which files match and which do not.
- Adjust the pattern before copying it into your config.
That is faster than discovering a bad pattern after a build fails.
Frequently asked questions
Is a glob the same as a regular expression?
No. Globs are simpler path-matching patterns, while regexes are more general and more complex.
Why do recursive patterns behave differently?
Because ** is the part that usually crosses directory boundaries, while * stays more local.
Can exclusions override matches?
Yes. That is why the order and composition of patterns can matter.
Final thought
If a pattern is going into a config file, test it first. Seeing the real matches is the quickest way to avoid a quiet build-time mistake.