Refactor createSpec to use importer feature instead of string replacement

String replacement was too error prone...

Author: jhnns

test/tools/createSpec.js

@@ -6,15 +6,10 @@ var path = require('path');
 
 var testFolder = path.resolve(__dirname, '../');
 var error = 'error';
-var filesWithTildeImports = [
-    'imports', 'import-other-style', 'import-css'
-];
 
 function createSpec(ext) {
     var basePath = path.join(testFolder, ext);
-    var nodeModulesPath = path.join(testFolder, 'node_modules');
-    var tildeReplacement = path.relative(basePath, nodeModulesPath) + path.sep;
-    var sassError;
+    var testModulePath = path.relative(basePath, path.join(testFolder, 'node_modules', 'test-module'));
 
     fs.readdirSync(path.join(testFolder, ext))
         .filter(function (file) {
@@ -23,41 +18,22 @@ function createSpec(ext) {
         .map(function (file) {
             var fileName = path.join(basePath, file);
             var fileWithoutExt = file.slice(0, -ext.length - 1);
-            var oldFileContent;
-            var newFileContent;
             var css;
 
-            if (filesWithTildeImports.indexOf(fileWithoutExt) > -1) {
-                // We need to replace all occurrences of '~' with relative paths
-                // so node-sass finds the imported files without webpack's resolving algorithm
-                oldFileContent = fs.readFileSync(fileName, 'utf8');
-                newFileContent = oldFileContent.replace(/~/g, tildeReplacement);
-                fs.writeFileSync(fileName, newFileContent, 'utf8');
-            }
-
-            try {
-                css = sass.renderSync({
-                    file: fileName,
-                    includePaths: [
-                        path.join(testFolder, ext, 'another'),
-                        path.join(testFolder, ext, 'from-include-path')
-                    ]
-                }).css;
-                fs.writeFileSync(path.join(basePath, 'spec', fileWithoutExt + '.css'), css, 'utf8');
-            } catch (err) {
-                // Capture the sass error, but don't crash the script in order to roll-back all temporary file changes
-                sassError = err;
-            }
-
-            if (filesWithTildeImports.indexOf(fileWithoutExt) > -1) {
-                fs.writeFileSync(fileName, oldFileContent, 'utf8');
-            }
+            css = sass.renderSync({
+                file: fileName,
+                importer: function (url) {
+                    return {
+                        file: url.replace(/^~test-module/, testModulePath)
+                    };
+                },
+                includePaths: [
+                    path.join(testFolder, ext, 'another'),
+                    path.join(testFolder, ext, 'from-include-path')
+                ]
+            }).css;
+            fs.writeFileSync(path.join(basePath, 'spec', fileWithoutExt + '.css'), css, 'utf8');
         });
-
-    if (sassError) {
-        // Now we can throw the sass error
-        throw sassError;
-    }
 }
 
 module.exports = createSpec;