jgardella / compat Goto Github PK

Implement detection for ES2016+ features:

2016 features

• exponentiation (**) operator
• Array.prototype.includes

2016 misc

• nested rest destructuring, declarations
• nested rest destructuring, parameters

2017 features

• Object.values
• Object.entries
• Object.getOwnPropertyDescriptors
• String padding
• async functions

2017 misc

• class extends null

Trying to run it in my project and get this error:

Failed to create JS table: Error: Cannot find module './data-common'
No previous compatibility table. Exiting.

I'm trying to use this on a linux OS and I'm getting the following error:

$ compat --target assets/js/
/usr/bin/env: ‘node\r’: No such file or directory

I think it's coming from:

I debugged with

$od -c index.js | head

and I got:

0000000   #   !       /   u   s   r   /   b   i   n   /   e   n   v    
0000020   n   o   d   e  \r  \n   l   e   t       y   a   r   g   s    

So, I'm guessing my shell doesn't like these windows(?) line endings?

If incompatibilities are detected, the program does not indicate failure by returning a non-zero status. Fixing this would make it easier to use this in CI settings.

Furthermore, the errors are not printed to stderr. It might be a good idea to print the errors to stderr.

On the following line:

https://github.com/jgardella/compat/blob/master/src/js/features/es6/syntax/octalAndBinaryLiterals/binaryLiterals.js#L13

we check for binary literal by matching 'b' in the lowercase version of the number.

However, 0xb is a valid ES5 hexadecimal literal. We should not check for existence of b, but that b exists after the initial 0.

Example:

IE11 does not support Element.prototype.remove.

From reading some of the source code, it doesn't look like that's a goal of this library, but I wanted to confirm.

Thanks for writing this!

Context

Compat uses the CanIUse repository to validate feature compatibility by grabbing the latest git commit.

Issue

This is hardcoded at line 181 from createTable.js: getLatestCommitSHA('fyrd', 'caniuse', 'heads/master')
In recent changes, the "master" branches got renamed to "main" to follow BLM movement, a seen here. Thus, it can no longer resolve and running compat now fails with an error:

stderr: (node:40588) UnhandledPromiseRejectionWarning: Error: Failed to load latest commit
at ClientRequest.<anonymous> ([MyPath]\node_modules\compat-cli\src\tableUpdater\createTable.js:158:16)

Impact:

No issues are found from compat, as the list fetching is never properly resolved. This makes the library's result unreliable (/unusable).

Fix

The easiest fix would be to hardcode the new main branch 'heads/main'. Maybe a better approach might be to have it fixed as the default but allow a config parameter url/branch name to be passed in case the repo or structure change in the future?