proptest VS regex

proptest: Property-based testing with random input generation.

Isn't proptest something that could handle this?

https://github.com/proptest-rs/proptest

Proptest is a Rust crate for property-based testing. Recently I wanted/needed to manually implement a proptest strategy for my own type, and I realized that there is not that much material on how to do it. So I wrote a post where I tried to describe what I learned. It's a bit niche, but I hope that someone at some point will find it useful.

Take a look at proptest.

Yes exactly, you can also add to this fuzzing and property based testing.

proptest is great! It generates random input data according to some rules, and if the input fails it saves random seed into a file so that failing inputs are guaranteed to be tested on the subsequent runs (as well as new random inputs). It also doesn't immediately stop on fail but tries to find a minimal failing input first.

The only other crate I could find is proptest, but it looks a lot more complicated, and I don't know if lets you skip the shrinking step as quickcheck does. I've been reading the book and going through the docs, but a quick answer would be appreciated.

We just released proptest 1.1.0, a property-testing framework for Rust. Proptest has recently found new maintainers, and this marks the first new release of proptest in ~2 years.

Hi, I'm working on a fuzzer, that fuzzes APIs based on OpenAPI specification. I'd like to implement shrinking. It means that when an interesting input (for the API) is found, I'd like to create the smallest possible input that still causes the same behaviour of the API. I'd like to implement a payload generation via proptest, because it already has the shrinking ability. I'm having issues implementing the JSON object as a proptest strategy. Here is what I tried so far. I explained it in a detail in stackoverflow question but it did not reach many people. Thanks for your help!

Third, if you're opting out of a compile-time safety guarantee in the name of performance, test heavily (high-coverage unit tests, property testing, fuzzing, differential fuzzing, etc.) and make use of tools like Loom and Miri's runtime data race detector for unsafe code, which can catch stuff that is beyond the scope of the compiler's guarantees.

The homepage has a benchmark that compares Zed's "insertion latency" to other editors, and this is the description:

> Open input.rs at the end of line 21 in rust-lang/regex. Type z 10 times, measure how long it takes for each z to display since hitting the z key.

Could someone clarify what that means? My interpretation of that was to go to https://github.com/rust-lang/regex/blob/master/regex-cli/arg... and start typing 'z' at the end of line 21, but that doesn't seem to make any sense. I guess that repo got refactored and those instructions are out of date?

We also used the avenue to sluggify the question title. We used regex to fish out and replace all occurrences of punctuation and symbol characters with an empty string and using the itertools crate, we joined the words back together into a single string, where each word is separated by a hyphen ("-").

Command-Line Rust taught me how to use crates like clap, assert_cmd, and regex. I felt lost before because I didn't know about Rust's ecosystem--which is arguably as important as the language itself. Also, looking up and comparing libraries is a tiring task! blessed.rs is nice but Command-Line Rust really saved me from analysis paralysis.

burntsushi actually regrets making regex replace return a Cow: https://github.com/rust-lang/regex/issues/676#issuecomment-6.... I’m glad it does, and wish it took an impl Into> there, for the reasons discussed in the issue, but burntsushi has a lot more experience of the practical outcomes of this. Just something more to think about.

I'm not familiar with the AoC problem. You might be able to. But RegexSet doesn't give you match offsets.

You can drop down to regex-automata, which does let you do multi-regex search and it will tell you which patterns match[1]. The docs have an example of a simple lexer[2]. But... that will only give you non-overlapping matches.

You can drop down to an even lower level of abstraction and get multi-pattern overlapping matches[3], but it's awkward. The comment there explains that I had initially tried to provide a higher level API for it, but was unsure of what the semantics should be. Getting the starting position in particular is a bit of a wrinkle.

[1]: https://docs.rs/regex-automata/latest/regex_automata/meta/in...

[2]: https://docs.rs/regex-automata/latest/regex_automata/meta/st...

[3]: https://github.com/rust-lang/regex/blob/837fd85e79fac2a4ea64...

It’s not quite that simple, but folks are working on it.

https://github.com/rust-lang/regex/issues/425#issuecomment-1...

https://github.com/helix-editor/helix/pull/211#issuecomment-...

Dependencies used: - regex - unicode_reader - rust decimal - tokio

https://www.cs.princeton.edu/courses/archive/fall19/cos226/l... and https://kean.blog/post/lets-build-regex are excellent introductions to implementing a (very) simplified regex engine: construct a nondetermistic finite state automaton for the regex, then perform a graph search on the resulting digraph; if the vertex corresponding to your end state is reachable, you have a match.

I think this exercise is valuable for anyone writing regexes to not only understand that there's less magic than one might think, but also to visualize a bunch of balls bouncing along an NFA - that bug you inevitably hit in production due to catastrophic backtracking now takes on a physical meaning!

Separately re: the OP, https://github.com/rust-lang/regex/issues/822 (and specifically BurntSushi's comment at the very end of the issue) adds really useful context to the paragraph in the OP about niche APIs: https://blog.burntsushi.net/regex-internals/#problem-request... - searching with multiple regexes simultaneously against a text is both incredibly complex and incredibly useful, and I can't wait to see what the community comes up with for this pattern!