Add support for Sass includePaths option

package.json

@@ -6,7 +6,8 @@
   "scripts": {
     "doc": "esdoc -c ./esdoc.json",
     "compile": "git clean -xdf lib && babel -d lib/ src/",
-    "prepublish": "npm run compile"
+    "prepublish": "npm run compile",
+    "test": "./node_modules/.bin/mocha test/**/* -- --harmony"
   },
   "repository": {
     "type": "git",
@@ -52,9 +53,13 @@
     "babel-plugin-transform-runtime": "^6.12.0",
     "babel-preset-es2016-node5": "^1.1.2",
     "babel-preset-react": "^6.11.1",
+    "babel-register": "^6.18.0",
+    "chai": "^3.5.0",
+    "chai-as-promised": "^6.0.0",
     "esdoc": "^0.4.8",
     "esdoc-es7-plugin": "0.0.3",
     "esdoc-plugin-async-to-sync": "^0.5.0",
-    "eslint": "^3.3.0"
+    "eslint": "^3.3.0",
+    "mocha": "^3.2.0"
   }
 }

src/css/sass.js

@@ -1,4 +1,5 @@
 import path from 'path';
+import fs from 'fs';
 import toutSuite from 'toutsuite';
 
 import {CompilerBase} from '../compiler-base';
@@ -48,15 +49,21 @@ export default class SassCompiler extends CompilerBase {
 
     paths.unshift('.');
 
+    const { includePaths } = this.compilerOptions
+    if (includePaths) {
+      sass.importer(this.buildImporterCallback(includePaths))
+      delete this.compilerOptions.includePaths;
+    }
+
     let opts = Object.assign({}, this.compilerOptions, {
       indentedSyntax: filePath.match(/\.sass$/i),
-      sourceMapRoot: filePath,		
+      sourceMapRoot: filePath,
     });
 
     let result = await new Promise((res,rej) => {
       sass.compile(sourceCode, opts, (r) => {
         if (r.status !== 0) {
-          rej(new Error(r.formatted));
+          rej(new Error(r.formatted || r.message));
           return;
         }
 
@@ -93,9 +100,15 @@ export default class SassCompiler extends CompilerBase {
 
     paths.unshift('.');
 
+    const { includePaths } = this.compilerOptions
+    if (includePaths) {
+      sass.importer(this.buildImporterCallback(includePaths))
+      delete this.compilerOptions.includePaths;
+    }
+
     let opts = Object.assign({}, this.compilerOptions, {
       indentedSyntax: filePath.match(/\.sass$/i),
-      sourceMapRoot: filePath,		
+      sourceMapRoot: filePath,
     });
 
     let result;
@@ -114,8 +127,67 @@ export default class SassCompiler extends CompilerBase {
     };
   }
 
+  buildImporterCallback (includePaths) {
+    const self = this;
+    return (function (request, done) {
+      let file
+      if (request.file) {
+        done();
+      } else {
+        // sass.js works in the '/sass/' directory
+        const cleanedRequestPath = request.resolved.replace(/^\/sass\//, '');
+        for (let includePath of includePaths) {
+          const filePath = path.resolve(includePath, cleanedRequestPath);
+          let variations = sass.getPathVariations(filePath);
+
+          file = variations
+            .map(self.fixWindowsPath.bind(self))
+            .reduce(self.importedFileReducer.bind(self), null);
+
+          if (file) {
+            const content = fs.readFileSync(file, { encoding: 'utf8' });
+            return sass.writeFile(file, content, () => {
+              done({ path: file })
+            });
+          }
+        }
+
+        if (!file) done();
+      }
+    });
+  }
+
+  importedFileReducer(found, path) {
+    // Find the first variation that actually exists
+    if (found) return found;
+
+    try {
+      const stat = fs.statSync(path);
+      if (!stat.isFile()) return null;
+      return path;
+    } catch(e) {
+      return null;
+    }
+  }
+
+  fixWindowsPath(file) {
+    // Unfortunately, there's a bug in sass.js that seems to ignore the different
+    // path separators across platforms. We need to fix this.
+    if (process.platform === 'win32' && file[0] === '/') {
+      file = file.slice(1);
+    }
+
+    if (file[0] === '_') {
+      const parts = file.slice(1).split(path.sep);
+      const dir = parts.slice(0, -1).join(path.sep);
+      const fileName = parts.reverse()[0];
+      file = path.resolve(dir, '_' + fileName);
+    }
+    return file
+  }
+
   getCompilerVersion() {
-    // NB: There is a bizarre bug in the node module system where this doesn't 
+    // NB: There is a bizarre bug in the node module system where this doesn't
     // work but only in saveConfiguration tests
     //return require('@paulcbetts/node-sass/package.json').version;
     return "4.1.1";

test/css/fixtures/importable.sass

@@ -0,0 +1,2 @@
+body, html
+  background: red

test/css/sass.test.js

@@ -0,0 +1,46 @@
+import path from 'path'
+import SassCompiler from '../../src/css/sass';
+
+describe('css/sass', function () {
+  this.timeout(5000)
+  it('should correctly compile valid sass', (done) => {
+    const sass = 'body, html\n  background: red';
+    const filename = 'file.sass';
+
+    const compiler = new SassCompiler();
+    compiler.compilerOptions = { comments: false };
+
+    compiler.compile(sass, filename)
+      .then((result) => {
+        expect(result.mimeType).to.equal('text/css');
+        expect(result.code).to.equal('body, html {\n  background: red; }\n');
+        done();
+      })
+      .catch((err) => {
+        done(err);
+      });
+  });
+
+  describe('when passing includePaths', () => {
+    it('should correctly resolve import paths', (done) => {
+      const sass = '@import "importable"';
+      const filename = 'file.sass';
+
+      const compiler = new SassCompiler();
+      compiler.compilerOptions = Object.assign({}, compiler.compilerOptions, {
+        includePaths: ['test/css/fixtures'],
+        comments: false
+      });
+
+      compiler.compile(sass, filename)
+        .then((result) => {
+          expect(result.mimeType).to.equal('text/css');
+          expect(result.code).to.equal('body, html {\n  background: red; }\n');
+          done();
+        })
+        .catch((err) => {
+          done(err);
+        });
+    })
+  })
+});

test/mocha.opts

@@ -0,0 +1,4 @@
+--require babel-register
+--require test/support.js
+--reporter spec
+--recursive

test/support.js

@@ -0,0 +1,4 @@
+import chai from 'chai'
+import chaiAsPromised from 'chai-as-promised'
+
+global.expect = chai.expect