Simplify extractVars, fixes edge cases. (#185)

Also make sure all regexp groups in tests are non-capturing.

mux_test.go

@@ -127,12 +127,12 @@ func TestHost(t *testing.T) {
 		},
 		{
 			title:        "Host route with pattern, additional capturing group, match",
-			route:        new(Route).Host("aaa.{v1:[a-z]{2}(b|c)}.ccc"),
+			route:        new(Route).Host("aaa.{v1:[a-z]{2}(?:b|c)}.ccc"),
 			request:      newRequest("GET", "http://aaa.bbb.ccc/111/222/333"),
 			vars:         map[string]string{"v1": "bbb"},
 			host:         "aaa.bbb.ccc",
 			path:         "",
-			hostTemplate: `aaa.{v1:[a-z]{2}(b|c)}.ccc`,
+			hostTemplate: `aaa.{v1:[a-z]{2}(?:b|c)}.ccc`,
 			shouldMatch:  true,
 		},
 		{
@@ -177,12 +177,12 @@ func TestHost(t *testing.T) {
 		},
 		{
 			title:        "Host route with hyphenated name and pattern, additional capturing group, match",
-			route:        new(Route).Host("aaa.{v-1:[a-z]{2}(b|c)}.ccc"),
+			route:        new(Route).Host("aaa.{v-1:[a-z]{2}(?:b|c)}.ccc"),
 			request:      newRequest("GET", "http://aaa.bbb.ccc/111/222/333"),
 			vars:         map[string]string{"v-1": "bbb"},
 			host:         "aaa.bbb.ccc",
 			path:         "",
-			hostTemplate: `aaa.{v-1:[a-z]{2}(b|c)}.ccc`,
+			hostTemplate: `aaa.{v-1:[a-z]{2}(?:b|c)}.ccc`,
 			shouldMatch:  true,
 		},
 		{
@@ -367,12 +367,12 @@ func TestPath(t *testing.T) {
 		},
 		{
 			title:        "Path route with multiple patterns with pipe, match",
-			route:        new(Route).Path("/{category:a|(b/c)}/{product}/{id:[0-9]+}"),
+			route:        new(Route).Path("/{category:a|(?:b/c)}/{product}/{id:[0-9]+}"),
 			request:      newRequest("GET", "http://localhost/a/product_name/1"),
 			vars:         map[string]string{"category": "a", "product": "product_name", "id": "1"},
 			host:         "",
 			path:         "/a/product_name/1",
-			pathTemplate: `/{category:a|(b/c)}/{product}/{id:[0-9]+}`,
+			pathTemplate: `/{category:a|(?:b/c)}/{product}/{id:[0-9]+}`,
 			shouldMatch:  true,
 		},
 		{
@@ -397,12 +397,12 @@ func TestPath(t *testing.T) {
 		},
 		{
 			title:        "Path route with multiple hyphenated names and patterns with pipe, match",
-			route:        new(Route).Path("/{product-category:a|(b/c)}/{product-name}/{product-id:[0-9]+}"),
+			route:        new(Route).Path("/{product-category:a|(?:b/c)}/{product-name}/{product-id:[0-9]+}"),
 			request:      newRequest("GET", "http://localhost/a/product_name/1"),
 			vars:         map[string]string{"product-category": "a", "product-name": "product_name", "product-id": "1"},
 			host:         "",
 			path:         "/a/product_name/1",
-			pathTemplate: `/{product-category:a|(b/c)}/{product-name}/{product-id:[0-9]+}`,
+			pathTemplate: `/{product-category:a|(?:b/c)}/{product-name}/{product-id:[0-9]+}`,
 			shouldMatch:  true,
 		},
 		{
@@ -415,6 +415,16 @@ func TestPath(t *testing.T) {
 			pathTemplate: `/{type:(?i:daily|mini|variety)}-{date:\d{4,4}-\d{2,2}-\d{2,2}}`,
 			shouldMatch:  true,
 		},
+		{
+			title:        "Path route with empty match right after other match",
+			route:        new(Route).Path(`/{v1:[0-9]*}{v2:[a-z]*}/{v3:[0-9]*}`),
+			request:      newRequest("GET", "http://localhost/111/222"),
+			vars:         map[string]string{"v1": "111", "v2": "", "v3": "222"},
+			host:         "",
+			path:         "/111/222",
+			pathTemplate: `/{v1:[0-9]*}{v2:[a-z]*}/{v3:[0-9]*}`,
+			shouldMatch:  true,
+		},
 	}
 
 	for _, test := range tests {
@@ -779,7 +789,7 @@ func TestQueries(t *testing.T) {
 		},
 		{
 			title:       "Queries route with regexp pattern with quantifier, additional capturing group",
-			route:       new(Route).Queries("foo", "{v1:[0-9]{1}(a|b)}"),
+			route:       new(Route).Queries("foo", "{v1:[0-9]{1}(?:a|b)}"),
 			request:     newRequest("GET", "http://localhost?foo=1a"),
 			vars:        map[string]string{"v1": "1a"},
 			host:        "",
@@ -824,7 +834,7 @@ func TestQueries(t *testing.T) {
 		},
 		{
 			title:       "Queries route with hyphenated name and pattern with quantifier, additional capturing group",
-			route:       new(Route).Queries("foo", "{v-1:[0-9]{1}(a|b)}"),
+			route:       new(Route).Queries("foo", "{v-1:[0-9]{1}(?:a|b)}"),
 			request:     newRequest("GET", "http://localhost?foo=1a"),
 			vars:        map[string]string{"v-1": "1a"},
 			host:        "",

regexp.go

@@ -300,14 +300,7 @@ func getHost(r *http.Request) string {
 }
 
 func extractVars(input string, matches []int, names []string, output map[string]string) {
-	matchesCount := 0
-	prevEnd := -1
-	for i := 2; i < len(matches) && matchesCount < len(names); i += 2 {
-		if prevEnd < matches[i+1] {
-			value := input[matches[i]:matches[i+1]]
-			output[names[matchesCount]] = value
-			prevEnd = matches[i+1]
-			matchesCount++
-		}
+	for i, name := range names {
+		output[name] = input[matches[2*i+2]:matches[2*i+3]]
 	}
 }