Support negotiation wildcards, fix #391 (#1112)

* support negotiation wildcards, fix #391

* fix typo

context.go

@@ -952,7 +952,18 @@ func (c *Context) NegotiateFormat(offered ...string) string {
 	}
 	for _, accepted := range c.Accepted {
 		for _, offert := range offered {
-			if accepted == offert {
+			// According to RFC 2616 and RFC 2396, non-ASCII characters are not allowed in headers,
+			// therefore we can just iterate over the string without casting it into []rune
+			i := 0
+			for ; i < len(accepted); i++ {
+				if accepted[i] == '*' || offert[i] == '*' {
+					return offert
+				}
+				if accepted[i] != offert[i] {
+					break
+				}
+			}
+			if i == len(accepted) {
 				return offert
 			}
 		}

context_test.go

@@ -1158,17 +1158,41 @@ func TestContextNegotiationFormat(t *testing.T) {
 func TestContextNegotiationFormatWithAccept(t *testing.T) {
 	c, _ := CreateTestContext(httptest.NewRecorder())
 	c.Request, _ = http.NewRequest("POST", "/", nil)
-	c.Request.Header.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
+	c.Request.Header.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9;q=0.8")
 
 	assert.Equal(t, MIMEXML, c.NegotiateFormat(MIMEJSON, MIMEXML))
 	assert.Equal(t, MIMEHTML, c.NegotiateFormat(MIMEXML, MIMEHTML))
 	assert.Empty(t, c.NegotiateFormat(MIMEJSON))
 }
 
+func TestContextNegotiationFormatWithWildcardAccept(t *testing.T) {
+	c, _ := CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest("POST", "/", nil)
+	c.Request.Header.Add("Accept", "*/*")
+
+	assert.Equal(t, c.NegotiateFormat("*/*"), "*/*")
+	assert.Equal(t, c.NegotiateFormat("text/*"), "text/*")
+	assert.Equal(t, c.NegotiateFormat("application/*"), "application/*")
+	assert.Equal(t, c.NegotiateFormat(MIMEJSON), MIMEJSON)
+	assert.Equal(t, c.NegotiateFormat(MIMEXML), MIMEXML)
+	assert.Equal(t, c.NegotiateFormat(MIMEHTML), MIMEHTML)
+
+	c, _ = CreateTestContext(httptest.NewRecorder())
+	c.Request, _ = http.NewRequest("POST", "/", nil)
+	c.Request.Header.Add("Accept", "text/*")
+
+	assert.Equal(t, c.NegotiateFormat("*/*"), "*/*")
+	assert.Equal(t, c.NegotiateFormat("text/*"), "text/*")
+	assert.Equal(t, c.NegotiateFormat("application/*"), "")
+	assert.Equal(t, c.NegotiateFormat(MIMEJSON), "")
+	assert.Equal(t, c.NegotiateFormat(MIMEXML), "")
+	assert.Equal(t, c.NegotiateFormat(MIMEHTML), MIMEHTML)
+}
+
 func TestContextNegotiationFormatCustom(t *testing.T) {
 	c, _ := CreateTestContext(httptest.NewRecorder())
 	c.Request, _ = http.NewRequest("POST", "/", nil)
-	c.Request.Header.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9,*/*;q=0.8")
+	c.Request.Header.Add("Accept", "text/html,application/xhtml+xml,application/xml;q=0.9;q=0.8")
 
 	c.Accepted = nil
 	c.SetAccepted(MIMEJSON, MIMEXML)