This is a first pass, unit tests still TODO, of adding a compiler flag to specify the line ending:
#1693
--newLine NEWLINE Emit newline: 'CRLF' (dos) or 'LF' (unix).

I'll next add unit tests as noted in this follow-up issue but please note any comments on code thus far:
#2918

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[DanielRosenwasser]

'--newLine' in single quotes.

Adjusted for comments thus far. I'll look into test cases tomorrow.

[mhegazy]

formatting, and use const.

Thanks @kmashint for the change. We will need a test for the new flag. to add a test,

• add a new test file in test\cases\compiler.ts with a comment at the top of // @newline: LF , another one with CRLF, and one for wrong input as well.
• add handling for the new switch in harnes.ts
  and in fileMetadataNames
• you would need to pass then the correct newline value to getNewLine in harness.ts
• jake runtests
• jake baseline-accept

I found and started to make the harness.ts adjustments; the runtests is taking forever so I'll check in the morning.

the runtests is taking forever

Yeah, there's been some perf drop in recent versions of Node that will make it...worse. I've been on 0.10.33. I've recently been working to parallelize the tests.

Stalled this week catching up on paid work ... should have some time on the weekend to work on unit tests.

I thought I had this working locally, but I'll try to find other examples of an expected failure in unit test cases.

1. compiler tests for tests/cases/compiler/newLineFlagWithCR.ts "before all" hook:
   Error: Unknown option for newLine: CR

[DanielRosenwasser]

Don't use tabs

I've introduced a @ normalizenewline option to work as the old one did in contextualTyping.js. I'll adjust for merge conflicts tomorrow.

OK, I've rebased my changes on top of microsoft/TypeScript. I tried using @ newline for both the new arguments and the old usage in contextualTyping.js but there were side-effects since the old usage affects not only the JS file but other debugging output files so I adjusted contextualTyping.js to use @ normalizenewline and all tests pass without further special treatment.

Thanks @kmashint!

Happy to contribute in a small way, I hope others find it useful as well.