fix(ArrayType): specify empty array mapping corner case

Empty array is mapped to undefined.

Closes #1511

Author: christopherthielen

src/urlMatcherFactory.js

@@ -502,25 +502,33 @@ Type.prototype.$asArray = function(mode, isSearch) {
       };
     }
 
-    function toArray(val) { return isArray(val) ? val : [ val ]; }
-    function fromArray(val) { return mode === "auto" && val && val.length === 1 ? val[0] : val; }
+    // Wrap non-array value as array
+    function arrayWrap(val) { return isArray(val) ? val : (isDefined(val) ? [ val ] : []); }
+    // Unwrap array value for "auto" mode. Return undefined for empty array.
+    function arrayUnwrap(val) {
+      switch(val.length) {
+        case 0: return undefined;
+        case 1: return mode === "auto" ? val[0] : val;
+        default: return val;
+      }
+    }
     function falsey(val) { return !val; }
 
     // Wraps type (.is/.encode/.decode) functions to operate on each value of an array
-    function arrayHandler(callback, alltrue) {
+    function arrayHandler(callback, allTruthyMode) {
       return function handleArray(val) {
-        val = toArray(val);
+        val = arrayWrap(val);
         var result = map(val, callback);
-        if (alltrue === true)
+        if (allTruthyMode === true)
           return result.filter(falsey).length === 0;
-        return fromArray(result);
+        return arrayUnwrap(result);
       };
     }
 
     // Wraps type (.equals) functions to operate on each value of an array
     function arrayEqualsHandler(callback) {
       return function handleArray(val1, val2) {
-        var left = toArray(val1), right = toArray(val2);
+        var left = arrayWrap(val1), right = arrayWrap(val2);
         if (left.length !== right.length) return false;
         for (var i = 0; i < left.length; i++) {
           if (!callback(left[i], right[i])) return false;

test/urlMatcherFactorySpec.js

@@ -211,29 +211,65 @@ describe("UrlMatcher", function () {
     it("should conditionally be wrapped in an array by default", inject(function($location) {
       var m = new UrlMatcher('/foo?param1');
 
-      expect(m.exec("/foo")).toEqual({});
-
+      // empty array [] is treated like "undefined"
+      expect(m.format({ param1: undefined })).toBe("/foo");
+      expect(m.format({ param1: [] })).toBe("/foo");
+      expect(m.format({ param1: "" })).toBe("/foo");
+      expect(m.format({ param1: "1" })).toBe("/foo?param1=1");
+      expect(m.format({ param1: [ "1" ] })).toBe("/foo?param1=1");
+      expect(m.format({ param1: [ "1", "2" ] })).toBe("/foo?param1=1&param1=2");
+
+      expect(m.exec("/foo")).toEqual({ param1: undefined });
+      expect(m.exec("/foo", {})).toEqual({ param1: undefined });
+      expect(m.exec("/foo", {param1: ""})).toEqual({ param1: undefined });
+      expect(m.exec("/foo", {param1: "1"})).toEqual({ param1: "1" }); // auto unwrap single values
+      expect(m.exec("/foo", {param1: [ "1", "2" ]})).toEqual({ param1: [ "1", "2" ] });
+
+      $location.url("/foo");
+      expect(m.exec($location.path(), $location.search())).toEqual( { param1: undefined } );
       $location.url("/foo?param1=bar");
-      expect(m.exec($location.path(), $location.search())).toEqual( { param1: 'bar' } );
-      expect(m.format({ param1: 'bar' })).toBe("/foo?param1=bar");
-
+      expect(m.exec($location.path(), $location.search())).toEqual( { param1: 'bar' } ); // auto unwrap
       $location.url("/foo?param1=bar&param1=baz");
       expect(m.exec($location.path(), $location.search())).toEqual( { param1: ['bar', 'baz'] } );
+
+      expect(m.format({ })).toBe("/foo");
+      expect(m.format({ param1: undefined })).toBe("/foo");
+      expect(m.format({ param1: "" })).toBe("/foo");
+      expect(m.format({ param1: 'bar' })).toBe("/foo?param1=bar");
+      expect(m.format({ param1: [ 'bar' ] })).toBe("/foo?param1=bar");
       expect(m.format({ param1: ['bar', 'baz'] })).toBe("/foo?param1=bar&param1=baz");
+
     }));
 
     it("should be wrapped in an array if array: true", inject(function($location) {
       var m = new UrlMatcher('/foo?param1', { params: { param1: { array: true } } });
 
-      expect(m.exec("/foo")).toEqual({});
-
+      // empty array [] is treated like "undefined"
+      expect(m.format({ param1: undefined })).toBe("/foo");
+      expect(m.format({ param1: [] })).toBe("/foo");
+      expect(m.format({ param1: "" })).toBe("/foo");
+      expect(m.format({ param1: "1" })).toBe("/foo?param1=1");
+      expect(m.format({ param1: [ "1" ] })).toBe("/foo?param1=1");
+      expect(m.format({ param1: [ "1", "2" ] })).toBe("/foo?param1=1&param1=2");
+
+      expect(m.exec("/foo")).toEqual({ param1: undefined });
+      expect(m.exec("/foo", {})).toEqual({ param1: undefined });
+      expect(m.exec("/foo", {param1: ""})).toEqual({ param1: undefined });
+      expect(m.exec("/foo", {param1: "1"})).toEqual({ param1: [ "1" ] });
+      expect(m.exec("/foo", {param1: [ "1", "2" ]})).toEqual({ param1: [ "1", "2" ] });
+
+      $location.url("/foo");
+      expect(m.exec($location.path(), $location.search())).toEqual( { param1: undefined } );
       $location.url("/foo?param1=bar");
       expect(m.exec($location.path(), $location.search())).toEqual( { param1: [ 'bar' ] } );
-      expect(m.format({ param1: 'bar' })).toBe("/foo?param1=bar");
-      expect(m.format({ param1: [ 'bar' ] })).toBe("/foo?param1=bar");
-
       $location.url("/foo?param1=bar&param1=baz");
       expect(m.exec($location.path(), $location.search())).toEqual( { param1: ['bar', 'baz'] } );
+
+      expect(m.format({ })).toBe("/foo");
+      expect(m.format({ param1: undefined })).toBe("/foo");
+      expect(m.format({ param1: "" })).toBe("/foo");
+      expect(m.format({ param1: 'bar' })).toBe("/foo?param1=bar");
+      expect(m.format({ param1: [ 'bar' ] })).toBe("/foo?param1=bar");
       expect(m.format({ param1: ['bar', 'baz'] })).toBe("/foo?param1=bar&param1=baz");
     }));
 
@@ -292,6 +328,36 @@ describe("UrlMatcher", function () {
       expect(m.format({ param1: [ 'bar', 'baz' ] })).toEqual("/foo/bar-baz");
     }));
 
+    it("should behave similar to multi-value query params", inject(function($location) {
+      var m = new UrlMatcher('/foo/:param1[]');
+
+      // empty array [] is treated like "undefined"
+      expect(m.format({ "param1[]": undefined })).toBe("/foo/");
+      expect(m.format({ "param1[]": [] })).toBe("/foo/");
+      expect(m.format({ "param1[]": "" })).toBe("/foo/");
+      expect(m.format({ "param1[]": "1" })).toBe("/foo/1");
+      expect(m.format({ "param1[]": [ "1" ] })).toBe("/foo/1");
+      expect(m.format({ "param1[]": [ "1", "2" ] })).toBe("/foo/1-2");
+
+      expect(m.exec("/foo/")).toEqual({ "param1[]": undefined });
+      expect(m.exec("/foo/1")).toEqual({ "param1[]": [ "1" ] });
+      expect(m.exec("/foo/1-2")).toEqual({ "param1[]": [ "1", "2" ] });
+
+      $location.url("/foo/");
+      expect(m.exec($location.path(), $location.search())).toEqual( { "param1[]": undefined } );
+      $location.url("/foo/bar");
+      expect(m.exec($location.path(), $location.search())).toEqual( { "param1[]": [ 'bar' ] } );
+      $location.url("/foo/bar-baz");
+      expect(m.exec($location.path(), $location.search())).toEqual( { "param1[]": ['bar', 'baz'] } );
+
+      expect(m.format({ })).toBe("/foo/");
+      expect(m.format({ "param1[]": undefined })).toBe("/foo/");
+      expect(m.format({ "param1[]": "" })).toBe("/foo/");
+      expect(m.format({ "param1[]": 'bar' })).toBe("/foo/bar");
+      expect(m.format({ "param1[]": [ 'bar' ] })).toBe("/foo/bar");
+      expect(m.format({ "param1[]": ['bar', 'baz'] })).toBe("/foo/bar-baz");
+    }));
+
     it("should be split on - in url and wrapped in an array if paramname looks like param[]", inject(function($location) {
       var m = new UrlMatcher('/foo/:param1[]');