exreg
v1.2.0
Published
A "reverse" regular expression module. Takes a regular expression and returns a string guaranteed to match it.
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exreg
A module to generate strings to match regular expressions
Creating Strings for regular expressions
While it's easy to create a regular expression to match a string, doing the opposite can be quite challenging.
This module will take a regular expression and generate a string that is guaranteed to be matched by that regular expression.
In version 1.x.x, a regular expression will always result in the same string and it will be the simplest string that
will match it. \d
will always result in a 0
; \b
will always result in an a
.
In version 2.x.x, I'll add support for more varied matching strings.
What regex features are supported?
The latest support can be found by running npm test
in this project. The specs will be listed as the tests pass.
However, for convenience, I'll list what's currently supported here:
- The
.
character - Normal characters
- The
|
character - Standard character classes
- Inclusive character classes of the form
[...]
- Quantifiers
- Groups (capturing and non-capturing)
- Special characters
Not currently supported:
- Lookaheads
- Captured Group references
- Word boundaries
- Start/end of string matchers
- Exclusive character classes of the form
[^...]
Bug reporting
If you find a regex such that the generated string is not a match please open an issue and include the failing regex.
Contributing
Any code that you'd like to contribute (and I'd be very appreciative of it) should be submitted via a Pull Request. There should be tests to support your change and they should pass.
Releasing a new version
Do the following:
- Make sure you're on develop and that you're in sync with the git repo
npm version
git push
- Create a PR into the
master
branch ofexreg
- Once this PR is approved and merged, the new version will be published