feat: update wikimedia/less.php from 4.x to 5.x (#4225)

* chore: Prep for upgrade to Less.php 5

The only two major changes in Less.php 5.0 are:

* Remove `import_callback`.
* Change default math from "always" (strictMath: false) to "parens-division".

The import_callback option was deprecated in 4.x, because it exposed a number
of internal classes, all of which had to be used in order to work, including
carefully obtaining and then returning the `pathAndUri[1]` value.

Upstream change: https://gerrit.wikimedia.org/r/1010962
Docs: https://github.com/wikimedia/less.php/blob/v4.4.1/lib/Less/Parser.php#L592-L617

== import_callback ==

The SetImportDirs() method has been available for a long time already,
and is instead given a simple string path (already resolved), and must
return `null|array{0:?string,1:?string}`. Thus if it doesn't want to
override, it can simply not return (implied null), which is equiv
to `[null,null]` and the second URI value is optional, defaulting to
the default.

== math ==

In Less.js 1.x-3.x the default was `strictMath: false`, which evaluates math eagerly,
instead of only "strictly" between parenthesis. This had the downside of
interpreting "/" slashes in newer CSS syntax as Less division, instead of as
separator between values in those CSS features (aspect-ratio, border-radius, font).

As such, Less.js 4.x and Less.php 5.x, rename "strictMath" to "math", with a new
third option "parens-division" as the default alongside "always"
(aka `strictMath: false`) and "parens" (aka `strictMath: true`). This new
option still eagerly evaluated math in most cases (plus, minus, multiply) but
no longer for division. I don't know if or when Flarum wants to adopt this new
default, but for now, to minimise disruption and unblock the Less.php upgrade,
I suggest simply setting `strictMath: false` explicitly so that Less.php 5
behaves the same as before.

This decouples the trivial Less.php upgrade from the (potentially non-trivial,
or unwanted) math migration.

Ref https://phabricator.wikimedia.org/T366445.
Ref https://github.com/wikimedia/less.php/blob/master/CHANGES.md.

== Custom properties ==

In Less.js 3.5, custom properties were natively supported which
included a change to no longer evaluate math expressions there.

This is separate from the general case, which remains eagerly
evaluated under the `strictMath:false` setting.

You can still perform calclations in custom properties with `calc()`.

Ref less/less.js#3317

* feat: update wikimedia/less.php from 4.x to 5.x

* fix: workaround the removed import_callback so that replaced less is still processed

* chore: styleci

---------

Co-authored-by: IanM <[email protected]>

Author: Krinkle

composer.json

@@ -172,7 +172,7 @@
         "symfony/postmark-mailer": "^7.0",
         "symfony/translation": "^7.0",
         "symfony/yaml": "^7.0",
-        "wikimedia/less.php": "^4.1",
+        "wikimedia/less.php": "^5.3",
         "plesk/ratchetphp": "v1.0.4"
     },
     "require-dev": {

framework/core/composer.json

@@ -91,7 +91,7 @@
         "symfony/translation-contracts": "^2.5",
         "symfony/yaml": "^7.0",
         "flarum/json-api-server": "^0.1.0",
-        "wikimedia/less.php": "^4.1"
+        "wikimedia/less.php": "^5.3"
     },
     "require-dev": {
         "flarum/testing": "^2.0",

framework/core/src/Frontend/Compiler/LessCompiler.php

@@ -11,11 +11,8 @@
 
 use Flarum\Frontend\Compiler\Source\FileSource;
 use Illuminate\Support\Collection;
-use Illuminate\Support\Str;
 use Less_Exception_Compiler;
-use Less_FileManager;
 use Less_Parser;
-use Less_Tree_Import;
 
 /**
  * @internal
@@ -83,9 +80,9 @@ protected function compile(array $sources): string
         try {
             $parser = new Less_Parser([
                 'compress' => true,
+                'strictMath' => false,
                 'cache_dir' => $this->cacheDir,
                 'import_dirs' => $this->importDirs,
-                'import_callback' => $this->lessImportOverrides ? $this->overrideImports($sources) : null,
             ]);
 
             if ($this->fileSourceOverrides) {
@@ -94,7 +91,15 @@ protected function compile(array $sources): string
 
             foreach ($sources as $source) {
                 if ($source instanceof FileSource) {
-                    $parser->parseFile($source->getPath());
+                    // If we have import overrides, parse the file content and apply them
+                    if ($this->lessImportOverrides && $this->lessImportOverrides->isNotEmpty()) {
+                        $content = file_get_contents($source->getPath());
+                        $content = $this->applyImportOverridesToContent($content);
+                        // Pass the original file path to maintain proper import resolution context
+                        $parser->parse($content, $source->getPath());
+                    } else {
+                        $parser->parseFile($source->getPath());
+                    }
                 } else {
                     $parser->parse($source->getContent());
                 }
@@ -137,6 +142,35 @@ protected function finalize(string $parsedCss): string
         return str_replace('url("../webfonts/', 'url("./fonts/', $parsedCss);
     }
 
+    /**
+     * Apply import overrides by replacing @import statements with inline content.
+     */
+    private function applyImportOverridesToContent(string $content): string
+    {
+        foreach ($this->lessImportOverrides as $override) {
+            $file = $override['file'];
+            $fileWithoutExt = preg_replace('/\.less$/i', '', $file);
+            $quotedFile = preg_quote($fileWithoutExt, '/');
+
+            // Match @import "path" or @import 'path' (with or without .less extension)
+            $pattern = '/@import\s+["\']'.$quotedFile.'(\.less)?["\'];?/i';
+
+            if (preg_match($pattern, $content)) {
+                // Read the override file content
+                $overrideContent = file_get_contents($override['newFilePath']);
+
+                // Replace the @import statement with the actual content
+                $content = preg_replace(
+                    $pattern,
+                    '/* Flarum override: '.$file.' */'."\n".$overrideContent."\n".'/* End override */',
+                    $content
+                );
+            }
+        }
+
+        return $content;
+    }
+
     protected function overrideSources(array $sources): array
     {
         foreach ($sources as $source) {
@@ -155,38 +189,6 @@ protected function overrideSources(array $sources): array
         return $sources;
     }
 
-    protected function overrideImports(array $sources): callable
-    {
-        $baseSources = (new Collection($sources))->filter(function ($source) {
-            return $source instanceof Source\FileSource;
-        })->map(function (FileSource $source) {
-            $path = realpath($source->getPath());
-            $path = Str::beforeLast($path, '/less/');
-
-            return [
-                'path' => $path,
-                'extensionId' => $source->getExtensionId(),
-            ];
-        })->unique('path');
-
-        return function (Less_Tree_Import $evald) use ($baseSources): ?array {
-            $pathAndUri = Less_FileManager::getFilePath($evald->getPath(), $evald->currentFileInfo);
-
-            $relativeImportPath = Str::of($pathAndUri[0])->split('/\/less\//');
-            $extensionId = $baseSources->where('path', $relativeImportPath->first())->pluck('extensionId')->first();
-
-            $overrideImport = $this->lessImportOverrides
-                ->where('file', $relativeImportPath->last())
-                ->firstWhere('extensionId', $extensionId);
-
-            if (! $overrideImport) {
-                return null;
-            }
-
-            return [$overrideImport['newFilePath'], $pathAndUri[1]];
-        };
-    }
-
     protected function getCacheDifferentiator(): ?array
     {
         return [

framework/core/tests/fixtures/less/custom_function.less

@@ -2,6 +2,6 @@
   color: green;
 }
 .dummy_func_test2 {
-  --x: is-flarum("not flarum") * 10;
+  width: is-flarum("not flarum") * 10px;
   --y: is-gt(1, 2);
 }

framework/core/tests/integration/extenders/ThemeTest.php

@@ -36,6 +36,10 @@ public function theme_extender_override_import_works()
 
         $response = $this->send($this->request('GET', '/'));
 
+        if ($response->getStatusCode() !== 200) {
+            echo "\n\nResponse body:\n".$response->getBody()->getContents()."\n\n";
+        }
+
         $this->assertEquals(200, $response->getStatusCode());
 
         $cssFilePath = $this->app()->getContainer()->make('filesystem')->disk('flarum-assets')->path('forum.css');
@@ -119,7 +123,7 @@ public function theme_extender_can_add_custom_function()
         $contents = file_get_contents($cssFilePath);
 
         $this->assertStringContainsString('.dummy_func_test{color:green}', $contents);
-        $this->assertStringContainsString('.dummy_func_test2{--x:1000;--y:false}', $contents);
+        $this->assertStringContainsString('.dummy_func_test2{width:1000px;--y:false}', $contents);
     }
 
     #[Test]