From 1f973328124daf3a4ec23908922b59898f26bb07 Mon Sep 17 00:00:00 2001
From: Theo <bbtfrr@gmail.com>
Date: Sat, 18 Mar 2017 11:43:20 +0800
Subject: [PATCH] refactor resolve function

---
 lib/createResolver.js | 51 +++++++++++++++++++++++++++++++++++++++++++
 lib/loader.js         | 16 +++-----------
 test/aliasTest.js     |  2 +-
 3 files changed, 55 insertions(+), 14 deletions(-)
 create mode 100644 lib/createResolver.js

diff --git a/lib/createResolver.js b/lib/createResolver.js
new file mode 100644
index 000000000..f284d5b96
--- /dev/null
+++ b/lib/createResolver.js
@@ -0,0 +1,51 @@
+function startsWith(string, searchString) {
+  var stringLength = string.length;
+  var searchLength = searchString.length;
+
+  // early out if the search length is greater than the search string
+  if(searchLength > stringLength) {
+    return false;
+  }
+  var index = -1;
+  while(++index < searchLength) {
+    if(string.charCodeAt(index) !== searchString.charCodeAt(index)) {
+      return false;
+    }
+  }
+  return true;
+}
+
+module.exports = function createResolver(alias) {
+  if(typeof alias !== "object" || Array.isArray(alias)) {
+    return function(url) { return url };
+  }
+
+  alias = Object.keys(alias).map(function(key) {
+    var onlyModule = false;
+    var obj = alias[key];
+    if(/\$$/.test(key)) {
+      onlyModule = true;
+      key = key.substr(0, key.length - 1);
+    }
+    if(typeof obj === "string") {
+      obj = {
+        alias: obj
+      };
+    }
+    obj = Object.assign({
+      name: key,
+      onlyModule: onlyModule
+    }, obj);
+    return obj;
+  });
+
+  return function(url) {
+    alias.forEach(function(obj) {
+      var name = obj.name;
+      if(url === name || (!obj.onlyModule && startsWith(url, name + "/"))) {
+        url = obj.alias + url.substr(name.length);
+      }
+    });
+    return url;
+  }
+}
diff --git a/lib/loader.js b/lib/loader.js
index 388508eab..b55b35f9c 100644
--- a/lib/loader.js
+++ b/lib/loader.js
@@ -6,6 +6,7 @@ var loaderUtils = require("loader-utils");
 var processCss = require("./processCss");
 var getImportPrefix = require("./getImportPrefix");
 var compileExports = require("./compile-exports");
+var createResolver = require("./createResolver");
 
 
 module.exports = function(content, map) {
@@ -15,6 +16,7 @@ module.exports = function(content, map) {
 	var root = query.root;
 	var moduleMode = query.modules || query.module;
 	var camelCaseKeys = query.camelCase || query.camelcase;
+	var resolve = createResolver(query.alias);
 
 	if(map !== null && typeof map !== "string") {
 		map = JSON.stringify(map);
@@ -69,19 +71,7 @@ module.exports = function(content, map) {
 				var match = result.urlItemRegExp.exec(item);
 				var idx = +match[1];
 				var urlItem = result.urlItems[idx];
-				var url = urlItem.url;
-				var loaderOptions = this.options.cssLoader;
-				if (loaderOptions && loaderOptions.alias) {
-					var alias = loaderOptions.alias;
-					Object.keys(alias).forEach(function(aliasName) {
-						var aliasValue = alias[aliasName];
-						var onlyModule = /\$$/.test(aliasName);
-						if (onlyModule) aliasName = aliasName.substr(0, aliasName.length - 1);
-						if ((!onlyModule && url.indexOf(aliasName + "/") === 0) || url === aliasName) {
-							url = aliasValue + url.substr(aliasName.length);
-						}
-					});
-				}
+				var url = resolve(urlItem.url);
 				idx = url.indexOf("?#");
 				if(idx < 0) idx = url.indexOf("#");
 				var urlRequest;
diff --git a/test/aliasTest.js b/test/aliasTest.js
index 6fdbd2d2f..2baf94634 100644
--- a/test/aliasTest.js
+++ b/test/aliasTest.js
@@ -20,7 +20,7 @@ describe("alias", function() {
   };
 
   function aliasOptions(alias) {
-    return { options: { context: "", cssLoader: { alias: alias }}}
+    return { query: { alias: alias }}
   }
 
   test("without", css, exports.without);