Support for `less >= v3.0.0`

[ngyikp]

Less.js v3 was just released: https://github.com/less/less.js/blob/master/CHANGELOG.md

Using the webpack resolver won't work correctly:

 FAIL  test/index.test.js
  ✓ should compile simple less without errors (305ms)
  ✕ should resolve all imports (20ms)
  ✕ should add all resolved imports as dependencies (12ms)
  ✕ should resolve all imports from node_modules using webpack's resolver (12ms)
  ✕ should add all resolved imports as dependencies, including node_modules (13ms)
  ✓ should resolve aliases as configured (13ms)
  ✓ should add all resolved imports as dependencies, including aliased ones (16ms)
  ✓ should resolve all imports from the given paths using Less' resolver (10ms)
  ✓ should add all resolved imports as dependencies, including those from the Less resolver (9ms)
  ✓ should allow to disable webpack's resolver by passing an empty paths array (9ms)
  ✕ should not try to resolve import urls (11ms)
  ✓ should allow to import non-less files (20ms)
  ✕ should compile data-uri function (15ms)
  ✕ should transform urls (20ms)
  ✕ should generate source maps with sourcesContent by default (13ms)
  ✕ should be possible to override sourceMap.outputSourceFiles (14ms)
  ✓ should install plugins (11ms)
  ✓ should not alter the original options object (9ms)
  ✕ should fail if a file is tried to be loaded from include paths and with webpack's resolver simultaneously (10ms)
  ✕ should provide a useful error message if the import could not be found (15ms)
  ✓ should provide a useful error message if there was a syntax error (11ms)
  ✕ should add a file with an error as dependency so that the watcher is triggered when the error is fixed (10ms)
  ✓ should be able to import a file with an absolute path (11ms)

[yuri-sakharov]

I just updated less to v3 and got

npm WARN less-loader@4.0.5 requires a peer of less@^2.3.1 but none is installed. You must install peer dependencies yourself.

[rejas]

That warning already appeared in the alpha version of less3 but didnt lead to an exception.
I used alpha3 the whole time withoput a problem, only with the official v3 something changed (which is okay and expected, since it was labeld "alpha").
Just a hint for the maintainer to look into what changed between alpha3 and final version.

[ludoo0d0a]

for me , it is an issue :

less-loader 4.0.5 + less3.0.0 leads me to non-resolvable import for this case:

@import "~mypackage/styles/properties.less";

and in package, usage of local import in less files

@import "./other/part";
^
Can't resolve './other/part' in ...

Solved after a few hours with a rollback on "less": "^2.3.1".

[smoliakov]

Can not resolve imports though WebStorm sees files.

less 3.0.0
less-loader 4.0.5

[rm-bergmann]

Just updated to LESS 3.0.0 and also getting the above issues. I will roll back to 2.3.1 for now

[alexander-akait]

PR welcome!

[yuri-sakharov]

I investigated and found:

• less@3.0.0-alpha.1 failed only one test after Allow less imports of paths like 'dir/css' less/less.js#2955
• less@3.0.0-alpha.2 tests doesn't start
• less@3.0.0-alpha.3 failed a lot of tests as @ngyikp described

[RinkAttendant6]

Are these issues also applicable with the Less resolver (as opposed to the Webpack resolver)?

I'm moving my compilation process from Grunt to Webpack and so far everything is OK with Less 3.0.0 (there was only one difference between the output of my two builds), but I don't want to run into anything problematic down the line.