Converting tabs to appropriate number of spaces for proper alignment.

[ankurnarkhede]

Marked version: 0.7.0

Markdown flavor: Markdown.pl|CommonMark|GitHub Flavored Markdown|n/a

Description

• Fixes Markdown containing tabs not converted properly to spaces #1559

Expectation

I expect the output to be the same what it was looking while I wrote the text.
The output is different when the text contains tabs.
I expect such output:

Result

This is the output I am getting:

What was attempted

I have included my package tab-to-space to convert tabs to the appropriate number of spaces in the Lexer prototype. This solves the alignment issue.

Contributor

• Test(s) exist to ensure functionality and minimize regression (if no tests added, list tests covering this PR); or,
• no tests required for this PR.
• If submitting new feature, it has been documented in the appropriate places.

Committer

In most cases, this should be a different person than the contributor.

• Draft GitHub release notes have been updated.
• CI is green (no forced merge required).
• Merge PR

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[ankurnarkhede]

@UziTech, @styfle
Seems like the CI tests are failing because the node_modules are cached, hence the package tab-to-space wasn't included.

[UziTech]

looks like the tests are failing because package-lock.json is not in sync with package.json. If you run npm i it should fix the error.

One of the benefits of marked is that there are no dependencies. So I don't think we should add one for this.

If we are changing the behavior of tabs we also need to make sure that it complies with the CommonMark spec. https://spec.commonmark.org/0.29/#tabs

[ankurnarkhede]

@UziTech at present, CommonMark is also not converting tabs to the appropriate number of spaces. Does it mean we have to leave this issue as it is?
CommonMark demo: Link

I recently found this issue in marked, and we had to write custom code in all the repositories where we are parsing markdown using marked NPM package.

[UziTech]

If you are looking to change the common mark spec then their forum is the correct place to discuss that.