Add missing message option for link_names

chat.go

@@ -696,6 +696,14 @@ func MsgOptionMetadata(metadata SlackMetadata) MsgOption {
 	}
 }
 
+// MsgOptionLinkNames finds and links user groups. Does not support linking individual users
+func MsgOptionLinkNames(linkName bool) MsgOption {
+	return func(config *sendConfig) error {
+		config.values.Set("link_names", strconv.FormatBool(linkName))
+		return nil
+	}
+}
+
 // UnsafeMsgOptionEndpoint deliver the message to the specified endpoint.
 // NOTE: USE AT YOUR OWN RISK: No issues relating to the use of this Option
 // will be supported by the library, it is subject to change without notice that

chat_test.go

@@ -185,6 +185,28 @@ func TestPostMessage(t *testing.T) {
 				"user_auth_message": []string{"Please!"},
 			},
 		},
+		"LinkNames true": {
+			endpoint: "/chat.postMessage",
+			opt: []MsgOption{
+				MsgOptionLinkNames(true),
+			},
+			expected: url.Values{
+				"channel":    []string{"CXXX"},
+				"token":      []string{"testing-token"},
+				"link_names": []string{"true"},
+			},
+		},
+		"LinkNames false": {
+			endpoint: "/chat.postMessage",
+			opt: []MsgOption{
+				MsgOptionLinkNames(false),
+			},
+			expected: url.Values{
+				"channel":    []string{"CXXX"},
+				"token":      []string{"testing-token"},
+				"link_names": []string{"false"},
+			},
+		},
 	}
 
 	once.Do(startServer)