Change endOfLine to lf by default for 2.0

[kachkaev]

Refs: #6888 (about Prettier 2.0), #6929 (about changing arrowParens to always)

End of Line option was added in #5327 and is available since Prettier 1.15. Given that using LF (Linux line endings) is a default choice in the software dev world, I decided to open this issue to bring the topic to a broader discussion.

I understand that changing defaults can cause large git diffs in some projects. However for the benefit of newly created projects, I suggest that the problem can be addressed by changing prettier.config.js in existing codebases. V2.0 is a great opportunity for breaking changes like this.

WDYT folks?

[lydell]

What are the benefits of changing the default here?

[Shinigami92]

Want to let you know that I'm using .editorconfig with end_of_line = lf

[kachkaev]

@Shinigami92 we also have endOfLine: "lf" configured, the suggestion is to avoid a need to do this 🙂

@lydell see #5320 and linked issues for context. My motivation for adding endOfLine to Prettier was a lot of pain we had to experience in our company. Because developers were contributing to repos from both *nix and Windows machines, end of lines ended up being different in neighbouring files and even jumped from one style to another in files between commits. In addition to a discomfort and unnecessary diffs coming out of this inconsistency, it was also a source of real bugs. If a javascript file starts with

#!/usr/bin/env node

and someone manages to commit it with CRLF, the above shebang directive no longer works. With the release of Prettier 1.15, we configured endOfLine: "lf" and had no CRLF problems ever since.

The reason we have endOfLine: "auto" by default is #92, which got more 👎 than 👍 in the end. It was addressed by #472 nearly three years ago, until then Prettier was enforcing LFs.

I'm not suggesting to remove the option completely, just in case someone still needs viewing files on the Windows 8 Nodepad. This is the least dated text editor I know of that requires CR characters in order to render multiple lines. Going further, I would suggest removing this option completely given that LF works in any modern editor.

[kachkaev]

Examples of mixed CRLF / LF line endings in popular repos (November 2018, before endOfLine: "lf" was introduced): #5320 (comment)

[kachkaev]

👀 ➡ ️#7435

[kachkaev]

Closed in #7435 🚀 Thanks to @thorn0 for merging! 🙌