From 7bcaa4681e8665ffb6ad81bcd0c8186522a59e2a Mon Sep 17 00:00:00 2001
From: Alexey Yaroshevich <zxqfox@gmail.com>
Date: Tue, 30 Jan 2018 10:54:36 +0300
Subject: [PATCH] wip

---
 packages/config/{index.js => config.js} | 32 ++++++++++++-------------
 packages/config/lib/merge.js            | 20 ++++++++++------
 packages/config/package.json            |  2 +-
 packages/config/test/async.test.js      |  8 +++----
 4 files changed, 34 insertions(+), 28 deletions(-)
 rename packages/config/{index.js => config.js} (94%)

diff --git a/packages/config/index.js b/packages/config/config.js
similarity index 94%
rename from packages/config/index.js
rename to packages/config/config.js
index 981414d8..9da8fbb4 100644
--- a/packages/config/index.js
+++ b/packages/config/config.js
@@ -9,7 +9,11 @@ var fs = require('fs'),
     merge = require('./lib/merge'),
     resolveSets = require('./lib/resolve-sets'),
 
-    basePlugins = [require('./plugins/resolve-level')];
+    basePlugins = [require('./plugins/resolve-level')],
+
+    accessAsync = (cwd, mode) =>
+        new Promise((resolve, reject) =>
+            fs.access(cwd, mode, (err) => !err ? resolve() : reject(err)));
 
 /**
  * Constructor
@@ -141,20 +145,16 @@ BemConfig.prototype.library = function(libName) {
                 lib = libs && libs[libName];
 
             if (lib !== undefined && typeof lib !== 'object') {
-                return Promise.reject('Invalid `libs` format');
+                throw new Error('Invalid `libs` format');
             }
 
-            var cwd = lib && lib.path || path.resolve('node_modules', libName);
-
-            return new Promise(function(resolve, reject) {
-                fs.exists(cwd, function(doesExist) {
-                    if (!doesExist) {
-                        return reject('Library ' + libName + ' was not found at ' + cwd);
-                    }
+            const cwd = lib && lib.path || path.resolve('node_modules', libName);
 
-                    resolve(cwd);
-                })
-            });
+            return accessAsync(cwd)
+                .then(() => cwd)
+                .catch(err => {
+                    throw new Error('Library ' + libName + ' was not found at ' + cwd + ('\n' + err));
+                });
         })
         .then(cwd => new BemConfig({ cwd: path.resolve(cwd) }));
 };
@@ -180,7 +180,7 @@ BemConfig.prototype.levelMap = function() {
             var allLevels = [].concat.apply([], libLevels.filter(Boolean)).concat(projectLevels);
 
             return allLevels.reduce((res, lvl) => {
-                res[lvl.path] = merge(res[lvl.path] || {}, lvl);
+                res[lvl.path] = merge([res[lvl.path] || {}, lvl]);
                 return res;
             }, {});
         });
@@ -395,7 +395,7 @@ function getLevelByConfigs(pathToLevel, options, allConfigs, root) {
         var conf = allConfigs[i],
             levels = conf.levels || [];
 
-        commonOpts = merge({}, conf, commonOpts);
+        commonOpts = merge([{}, conf, commonOpts]);
 
         for (var j = 0; j < levels.length; j++) {
             var level = levels[j];
@@ -403,13 +403,13 @@ function getLevelByConfigs(pathToLevel, options, allConfigs, root) {
             if (level === undefined || level.path !== absLevelPath) { continue; }
 
             // works like deep extend but overrides arrays
-            levelOpts = merge({}, level, levelOpts);
+            levelOpts = merge([{}, level, levelOpts]);
         }
 
         if (conf.root) { break; }
     }
 
-    levelOpts = merge(commonOpts, levelOpts);
+    levelOpts = merge([commonOpts, levelOpts]);
 
     delete levelOpts.__source;
     delete levelOpts.path;
diff --git a/packages/config/lib/merge.js b/packages/config/lib/merge.js
index 6fed789f..bfe9ac74 100644
--- a/packages/config/lib/merge.js
+++ b/packages/config/lib/merge.js
@@ -4,14 +4,20 @@ var mergeWith = require('lodash.mergewith');
 
 /**
  * Merge all arguments to firt one.
+ *
  * Consider arrays as simple value and not deep merge them.
- * @param {Array|Object} configs - array of configs or positional arguments
- * @return {Object}
+ *
+ * @example
+ * result: {levels: Array<{path: string, layer: string}>, sets: Object<string,string|Array>}
+ *
+ * @param {Array<Object>} configs - array of configs
+ * @returns {Object}
  */
 module.exports = function merge(configs) {
-    var args = Array.isArray(configs) ? configs : Array.from(arguments);
-    args.push(function(objValue, srcValue) {
-        if (Array.isArray(objValue)) { return srcValue; }
-    });
-    return mergeWith.apply(null, args);
+    return mergeWith.apply(null, [].concat(
+        Array.isArray(configs) ? configs : Array.from(arguments),
+        function(objValue, srcValue) {
+            if (Array.isArray(objValue)) { return srcValue; }
+        }
+    ));
 };
diff --git a/packages/config/package.json b/packages/config/package.json
index d22d98ae..bccaf00f 100644
--- a/packages/config/package.json
+++ b/packages/config/package.json
@@ -5,7 +5,7 @@
   "publishConfig": {
     "access": "public"
   },
-  "main": "index.js",
+  "main": "config.js",
   "scripts": {
     "specs": "mocha",
     "cover": "nyc mocha",
diff --git a/packages/config/test/async.test.js b/packages/config/test/async.test.js
index 95a6016f..baf790a5 100644
--- a/packages/config/test/async.test.js
+++ b/packages/config/test/async.test.js
@@ -290,13 +290,13 @@ describe('async', () => {
             }
         }]);
 
-        return bemConfig().library('lib1').catch(err => expect(err).to.equal('Invalid `libs` format'));
+        return bemConfig().library('lib1').catch(err => expect(err).to.match(/Invalid `libs` format/));
     });
 
     it('should throw if lib was not found', () => {
         const bemConfig = config();
 
-        return bemConfig().library('lib1').catch(err => expect(err.includes('Library lib1 was not found at')).to.equal(true));
+        return bemConfig().library('lib1').catch(err => expect(err).to.match(/Library lib1 was not found at /));
     });
 
     it('should throw if lib was not found', () => {
@@ -310,8 +310,8 @@ describe('async', () => {
         }]);
 
         return Promise.all([
-            bemConfig().library('lib1').catch(err => expect(err.includes('Library lib1 was not found at')).to.equal(true)),
-            bemConfig().library('lib2').catch(err => expect(err.includes('Library lib2 was not found at')).to.equal(true))
+            bemConfig().library('lib1').catch(err => expect(err).to.match(/Library lib1 was not found at/)),
+            bemConfig().library('lib2').catch(err => expect(err).to.match(/Library lib2 was not found at/))
         ]);
     });