[MAJOR]: Removed deprecated npm-sass and added dart-sass.

* Removed npm-sass, added dart-sass, migrated dependecy logic from npm-sass
* Fixed a bunch of lint issues in the imported npm-sass code
* Fixed issue with sass imports within node_modules folder
* Amended fix as per conversation with team, also added extra logging

helpers/importer.js

@@ -0,0 +1,29 @@
+const local = require('./local');
+const resolve = require('./resolver');
+
+module.exports = function (options) {
+  const importerOptions = options || {};
+
+  function importer(url, file, done) {
+    let importerUrl = url;
+    if (importerOptions.aliases && importerOptions.aliases[importerUrl]) {
+      importerUrl = importerOptions.aliases[importerUrl];
+    }
+
+    local(importerUrl, file, function (err, isLocal) {
+      if (err || isLocal) {
+        done({ file: importerUrl });
+      } else {
+        resolve(importerUrl, file)
+          .catch(function () { return importerUrl; })
+          .then(function (path) {
+            const importerPath = path.replace(/\.css$/, '');
+            return { file: importerPath };
+          })
+          .then(done);
+      }
+    });
+  }
+
+  return importer;
+};

helpers/local.js

@@ -0,0 +1,35 @@
+const path = require('path');
+const glob = require('glob');
+
+module.exports = function (url, file, done) {
+  // if url starts with . or / then assume it's a local/relative path
+  if (['.', path.sep].indexOf(url.substr(0, 1)) > -1) {
+    return done(null, true);
+  }
+
+  // otherwise construct a glob to match possible relative file paths
+  const basedir = path.dirname(file);
+
+  const bits = url.split(path.sep);
+
+  let filename = bits.pop();
+  const filepath = bits.join(path.sep);
+
+  // support _ prefixing of filenames
+  if (filename[0] !== '_') {
+    filename = '?(_)' + filename;
+  }
+
+  // match .scss, .sass or .css if the extension is not defined
+  if (filename.indexOf('.') === -1) {
+    filename += '.@(sa|c|sc)ss';
+  }
+
+  const target = path.join(basedir, filepath, filename);
+
+  // test the constructed glob against the file system for possible matches
+  glob(target, function (err, list) {
+    done(err, list.length);
+  });
+  return null;
+};

helpers/resolver.js

@@ -0,0 +1,16 @@
+const Package = require('./resolver/package');
+const Import = require('./resolver/import');
+const nearestPackageRoot = require('./resolver/nearest-package-root');
+
+module.exports = function (importUrl, importOriginPath) {
+  const _import = new Import(importUrl);
+
+  return nearestPackageRoot(_import.packageName(), importOriginPath).then(function (packageRoot) {
+    const _package = new Package(packageRoot);
+
+    if (_import.isEntrypoint()) {
+      return _package.fullPathToEntrypoint();
+    }
+    return _package.root(_import.specifiedFilePath());
+  });
+};

helpers/resolver/import.js

@@ -0,0 +1,32 @@
+const path = require('path');
+
+function Import(importUrl) {
+  this.importUrl = importUrl;
+}
+
+Import.prototype.isScoped = function () {
+  return this.importUrl[0] === '@';
+};
+
+Import.prototype.packageName = function () {
+  if (this.isScoped()) {
+    return this.importUrl.split(path.sep, 2).join(path.sep);
+  }
+  return this.importUrl.split(path.sep, 1)[0];
+};
+
+Import.prototype.isEntrypoint = function () {
+  const safePathSplitPattern = new RegExp(path.sep + '.');
+  const pathSegmentCount = this.importUrl.split(safePathSplitPattern).length;
+
+  if (this.isScoped()) {
+    return pathSegmentCount === 2;
+  }
+  return pathSegmentCount === 1;
+};
+
+Import.prototype.specifiedFilePath = function () {
+  return this.importUrl.slice(this.packageName().length);
+};
+
+module.exports = Import;

helpers/resolver/nearest-package-root.js

@@ -0,0 +1,32 @@
+const path = require('path');
+const findup = require('findup');
+
+/**
+ * @param {string} importOriginPath Path of file that made @import reference
+ */
+module.exports = function (packageName, importOriginPath) {
+  const pathToFind = path.join('node_modules', packageName, 'package.json');
+  const dirnameOfImportOrigin = path.dirname(importOriginPath);
+  let handleFoundPath;
+
+  const promise = new Promise(function (resolve, reject) {
+    handleFoundPath = function (err, nearestPackageParent) {
+      if (err) {
+        try {
+          return resolve(path.dirname(require.resolve(`${packageName}/package.json`)));
+        } catch (e) {
+          console.log(`Failed to find module ${packageName}/package.json for ${importOriginPath}`, e);
+        }
+        return reject(err);
+      }
+
+      const packageJSONLocation = path.join(nearestPackageParent, 'node_modules', packageName);
+
+      return resolve(packageJSONLocation);
+    };
+  });
+
+  findup(dirnameOfImportOrigin, pathToFind, handleFoundPath);
+
+  return promise;
+};

helpers/resolver/package.js

@@ -0,0 +1,29 @@
+const path = require('path');
+
+function Package(rootPath) {
+  this.root = path.join.bind(null, rootPath);
+  this.JSON = require(this.root('package.json'));
+}
+
+Package.prototype.fullPathToEntrypoint = function () {
+  return this.root(this.entrypoint());
+};
+
+Package.prototype.entrypoint = function () {
+  if (this.JSON.sass) {
+    return this.JSON.sass;
+    // look for "style" declaration in package.json
+  } else if (this.JSON.style) {
+    return this.JSON.style;
+    // look for "styles" declaration in package.json
+  } else if (this.JSON.styles) {
+    return this.JSON.styles;
+    // look for a css/sass/scss file in the "main" declaration in package.json
+  } else if (/\.(sa|c|sc)ss$/.test(this.JSON.main)) {
+    return this.JSON.main;
+    // otherwise assume ./styles.scss
+  }
+  return 'styles';
+};
+
+module.exports = Package;

package.json

@@ -28,14 +28,15 @@
     "cp": "^0.2.0",
     "dotenv": "^4.0.0",
     "duplexify": "^3.5.0",
+    "findup": "^0.1.5",
     "hof-transpiler": "^2.0.2",
     "lodash.merge": "^4.6.0",
     "lodash.throttle": "^4.1.1",
     "lodash.uniq": "^4.5.0",
     "minimatch": "^3.0.3",
     "minimist": "^1.2.0",
     "mkdirp": "^0.5.1",
-    "npm-sass": "^2.2.1",
+    "sass": "^1.35.1",
     "uglify-js": "^2.8.22",
     "witch": "^1.0.0"
   },

tasks/sass/index.js

@@ -2,7 +2,8 @@
 
 const fs = require('fs');
 const path = require('path');
-const sass = require('npm-sass');
+const sass = require('sass');
+const importer = require('../../helpers/importer');
 
 const mkdir = require('../../lib/mkdir');
 
@@ -17,9 +18,17 @@ module.exports = config => {
     .then(() => new Promise((resolve, reject) => {
       const aliases = {};
       if (config.theme) {
+        console.log('Applying theme: ' + config.theme);
         aliases.$$theme = `hof-theme-${config.theme}`;
       }
-      sass(config.sass.src, { aliases }, (err, result) => err ? reject(err) : resolve(result.css));
+
+      sass.render({
+        file: config.sass.src,
+        importer: importer({ aliases }),
+        aliases
+      }, function (err, result) {
+        err ? reject(err) : resolve(result.css);
+      });
     }))
     .then(css => new Promise((resolve, reject) => {
       fs.writeFile(out, css, err => err ? reject(err) : resolve());