🔧 MAINTAIN: Add mypy type-checking

[hukkin]

Closes #19

[codecov]

Codecov Report

Merging #64 (515fee0) into master (3a5bdcc) will increase coverage by 0.06%.
The diff coverage is 96.05%.

@@ Coverage Diff @@ ## master #64 +/- ## ========================================== + Coverage 95.69% 95.75% +0.06%  ========================================== Files 78 78 Lines 3970 3984 +14 ========================================== + Hits 3799 3815 +16  + Misses 171 169 -2 

Flag	Coverage Δ
pytests	95.75% <96.05%> (+0.06%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
markdown_it/common/utils.py	74.35% <0.00%> (+2.75%)	⬆️
markdown_it/token.py	91.76% <77.77%> (-1.01%)	⬇️
markdown_it/common/entities.py	92.30% <100.00%> (ø)
markdown_it/common/normalize_url.py	95.23% <100.00%> (ø)
markdown_it/extensions/anchors/index.py	100.00% <100.00%> (ø)
markdown_it/extensions/container/index.py	97.87% <100.00%> (+0.02%)	⬆️
markdown_it/extensions/deflist/index.py	94.96% <100.00%> (ø)
markdown_it/extensions/footnote/index.py	95.16% <100.00%> (+0.01%)	⬆️
markdown_it/extensions/tasklists/__init__.py	75.00% <100.00%> (+0.35%)	⬆️
markdown_it/main.py	90.98% <100.00%> (ø)
... and 14 more

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[hukkin]

I simply commented this function out, because str.replace() takes strings as input, not re.Patterns, so this is probably broken.

[chrisjsewell]

I will get round to looking at this eventually! Just want to make sure I look thoroughly, since its touching core code

[hukkin]

I rebased on master, and added one more commit that adds no_implicit_optional = True mypy configuration. This is to conform to updated PEP 484. Eventually this will be default mypy configuration too.

[chrisjsewell]

👍

this will be default mypy configuration too.

TBH it would be so much nicer and concise if you could use the typescript ? notation:

def func(a: Employee? = None): pass

[hukkin]

I think I've seen some discussion around that Optional syntax somewhere. Python typing is moving forward at quite a rapid pace so maybe one day we'll see that. In the next Python release we already get union types with TypeX | TypeY which I really like :)

[chrisjsewell]

Oh thats nice 😄 Yeh for typing, I think they should just copy everything from typescript, which they are basically gradually doing

[hukkin]

Haha yeh seems so. Btw. the new union syntax obviously lets us do int | None which is more concise than Optional[int] and requires no import from typing, so partially solves the problem.