Replace line-parsing RegEx by manual code

[Swatinem]

Replace line-parsing RegEx by manual code

This avoids pulling in regex and lazy_static and makes this a true
zero-dependency crate.

[codecov]

Codecov Report

Merging #26 into master will increase coverage by 0.71%.
The diff coverage is 100%.

@@            Coverage Diff             @@
##           master      #26      +/-   ##
==========================================
+ Coverage   91.09%   91.81%   +0.71%     
==========================================
  Files          18       18              
  Lines         584      623      +39     
==========================================
+ Hits          532      572      +40     
+ Misses         52       51       -1

Impacted Files	Coverage Δ
dotenv/src/parse.rs	97.25% <100%> (+0.03%)	⬆️
dotenv_codegen_implementation/src/lib.rs	0% <0%> (ø)	⬆️
dotenv/src/iter.rs	96.15% <0%> (+3.84%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update c41d4c9...2c25991. Read the comment docs.

[ZoeyR]

Mostly looks great! I'm always happy to remove deps when possible. One thing I'd like though is if you undid the rustfmt run. As much as I'd like the code to be clean, it adds noise to the PR unrelated to the functional changes.

[Swatinem]

Thanks for the quick review :-)
BTW, is there some kind of official spec for all of this? Allowing whitespace around the = would be a change to the regex that was there before. Also I think I made a mistake around export. I’m not sure if it is a reserved keyword or it can just as well be a var itself, like in export="some value"?

It will take some time for me to revise, this was just a quick experiment to see how far I come :-)

[ZoeyR]

There is no official spec for this. It's based off of https://github.com/bkeepers/dotenv but there is no official spec. We currently implement only a subset of the parsing capabilities of the original ruby gem.

[Swatinem]

I completely rewrote this with something resembling a "real" parser… And updated the tests to verify the new behavior (whitespace around =, treating export as key itself).

[ZoeyR]

Looks good! The pipeline failures seem to be due to some flakiness with cargo-junit. I'm rerunning them now.

[Swatinem]

some flakiness with cargo-junit

No, it was a real failure… I added a comment why those two ifs you suggested to merge need to be separate…

[ZoeyR]

Oh right, I see the logic issue now. I do need to fix the pipeline though to error out better though it seems.