Cannot put import by reference inside of a mixin

[blakemann]

I have been working on a complex importing strategy where I set all of my paths in a config file, and then use a mixin to import various different components as needed.

This approach doesn't seem to work well with files imported by reference, however. It seems that importing a file by reference inside of a mixin in this way causes it to output all of the contents of the file, and not just what is used.

To give you a very simplified example, I have something like this:

// config.less

// Normally the sub-mixin calls would be controlled by variables passed in, but for simplicity, let's say both get called always
.importer(){
    .import-certain-file();
    .import-last-file();
}

.import-certain-file(){
    @import "certain-file";
}

.import-last-file(){
    @import (reference) "last-file";
}
.import-last-file();

// certain-file.less

h1 {
    color: black;
}

// last-file.less

._color-white {
    color: white;
}

// main.less

@import "config";
.importer();

h1 {
    &:extend(._color-white);
}

So, certain-file.less contains a rule setting h1 to be black, but I want to override that in my main less file.. using a class name that was specifically made to be extended (imported by reference so that the original class name of ._color-white is not output into my code)

But that messes with the (reference) import, giving me this final output:

h1 {
    color: black;
}
._color-white, h1 {
    color: white;
}

Which technically works, but means I've got extra unwanted selectors being dropped into my code.. which is especially bad when in reality, my last-file.less is a big file full of "extension" classes, many of which don't even get used on every project.

I believe the problem lies in the fact that importing by reference inside of a mixin causes all styles inside that file to be output, rather than just when they are used.

[blakemann]

I think I may have rushed the logic on this a bit, as I'm now realizing that the order of me calling the mixin and importing the file does make sense the way it is, as I am calling the mixin after the original import call. That's what I get for staring at it for too long. I think the focus of this issue should be shifted to the fact that I can't put the (reference) import inside of the mixin without losing the reference functionality. I'm going to edit the text a bit to reflect this.

[blakemann]

Alright, I've adjusted the issue to take out the parts related to my original misconceptions. Your note about the mixin being able to be called before it is defined is actually a really useful point, which could solve my problem completely, regardless of the issue that's now highlighted in this case, but I still think this issue could be a potential problem in some other use-cases.

Sorry for the confusion!

[seven-phases-max]

Ah, I guess this way it becomes similar to #1896 (not exactly the same but internally it's identical stuff I guess) but probably it's better to keep open just to have more test examples for reference when worked out (I'm assigning same lables as in #1896).

[SomMeri]

This should be fixed by #2729 .