MDL-61394 core_scss: Add unit tests for SassC compilation

This patch also adds a test in theme_boost to verify that boost
can be succesfully compiled without errors by SassC.

lib/outputlib.php

@@ -1475,7 +1475,7 @@ class theme_config {
             // Compile!
             $compiled = $compiler->to_css();
 
-        } catch (\Leafo\ScssPhp\Exception $e) {
+        } catch (\Exception $e) {
             $compiled = false;
             debugging('Error while compiling SCSS: ' . $e->getMessage(), DEBUG_DEVELOPER);
         }

lib/tests/scss_test.php

@@ -70,6 +70,61 @@ class core_scss_testcase extends advanced_testcase {
         ];
     }
 
+    /**
+     * Test cases for SassC compilation.
+     */
+    public function scss_compilation_provider() {
+        return [
+            'simple' => [
+                'scss' => '$font-stack: Helvetica, sans-serif;
+                           $primary-color: #333;
+
+                           body {
+                             font: 100% $font-stack;
+                             color: $primary-color;
+                           }',
+                'expected' => <<<CSS
+body {
+  font: 100% Helvetica, sans-serif;
+  color: #333; }
+
+CSS
+            ],
+            'nested' => [
+                'scss' => 'nav {
+                             ul {
+                               margin: 0;
+                               padding: 0;
+                               list-style: none;
+                             }
+
+                           li { display: inline-block; }
+
+                           a {
+                             display: block;
+                             padding: 6px 12px;
+                             text-decoration: none;
+                           }
+                         }',
+                'expected' => <<<CSS
+nav ul {
+  margin: 0;
+  padding: 0;
+  list-style: none; }
+
+nav li {
+  display: inline-block; }
+
+nav a {
+  display: block;
+  padding: 6px 12px;
+  text-decoration: none; }
+
+CSS
+            ]
+        ];
+    }
+
     /**
      * @dataProvider is_valid_file_provider
      */
@@ -78,4 +133,22 @@ class core_scss_testcase extends advanced_testcase {
         $pathvalid = phpunit_util::call_internal_method($scss, 'is_valid_file', [$path], \core_scss::class);
         $this->assertSame($valid, $pathvalid);
     }
-}
+
+    /**
+     * Test that we can use the SassC compiler if it's provided.
+     *
+     * @dataProvider scss_compilation_provider
+     * @param string $scss The raw scss to compile.
+     * @param string $expectedcss The expected CSS output.
+     */
+    public function test_scss_compilation_with_sassc($scss, $expectedcss) {
+        if (!defined('PHPUNIT_PATH_TO_SASSC')) {
+            $this->markTestSkipped('Path to SassC not provided');
+        }
+
+        $this->resetAfterTest();
+        set_config('pathtosassc', PHPUNIT_PATH_TO_SASSC);
+        $compiler = new core_scss();
+        $this->assertSame($compiler->compile($scss), $expectedcss);
+    }
+}

theme/boost/tests/scss_test.php

@@ -0,0 +1,50 @@
+<?php
+// This file is part of Moodle - http://moodle.org/
+//
+// Moodle is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// Moodle is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with Moodle.  If not, see <http://www.gnu.org/licenses/>.
+
+/**
+ * This file contains the unittests for boost's scss compilation.
+ *
+ * @package   theme_boost
+ * @copyright 2018 Cameron Ball <[email protected]>
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+
+defined('MOODLE_INTERNAL') || die();
+
+/**
+ * Unit tests for scss compilation.
+ *
+ * @package   theme_boost
+ * @copyright 2016 onwards Ankit Agarwal
+ * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
+ */
+class theme_boost_scss_testcase extends advanced_testcase {
+    /**
+     * Test that boost can be compiled using SassC (the defacto implemention).
+     */
+    public function test_scss_compilation_with_sassc() {
+        if (!defined('PHPUNIT_PATH_TO_SASSC')) {
+            $this->markTestSkipped('Path to SassC not provided');
+        }
+
+        $this->resetAfterTest();
+        set_config('pathtosassc', PHPUNIT_PATH_TO_SASSC);
+
+        $this->assertNotEmpty(
+            theme_config::load('boost')->get_css_content_debug('scss', null, null)
+        );
+    }
+}