PLT-4847 Fix formatting of links imported from Slack. (#4674)

This fixes mailto: links built from email addresses posted to Slack as
described in the ticket, but also fixes any other type of URL that has
been auto-linked in the Slack messages.

2 files changed, 35 insertions, 0 deletions

diff --git a/api/slackimport.go b/api/slackimport.go
index 15f5f43f4..1225e7833 100644
--- a/api/slackimport.go
+++ b/api/slackimport.go
@@ -494,6 +494,19 @@ func SlackConvertChannelMentions(channels []SlackChannel, posts map[string][]Sla
 	return posts
 }
 
+func SlackConvertPostsMarkup(posts map[string][]SlackPost) map[string][]SlackPost {
+	// Convert URLs in Slack's format to Markdown format.
+	regex := regexp.MustCompile(`<([^|<>]+)\|([^|<>]+)>`)
+
+	for channelName, channelPosts := range posts {
+		for postIdx, post := range channelPosts {
+			posts[channelName][postIdx].Text = regex.ReplaceAllString(post.Text, "[$2]($1)")
+		}
+	}
+
+	return posts
+}
+
 func SlackImport(fileData multipart.File, fileSize int64, teamID string) (*model.AppError, *bytes.Buffer) {
 	// Create log file
 	log := bytes.NewBufferString(utils.T("api.slackimport.slack_import.log"))
@@ -536,6 +549,7 @@ func SlackImport(fileData multipart.File, fileSize int64, teamID string) (*model
 
 	posts = SlackConvertUserMentions(users, posts)
 	posts = SlackConvertChannelMentions(channels, posts)
+	posts = SlackConvertPostsMarkup(posts)
 
 	addedUsers := SlackAddUsers(teamID, users, log)
 	botUser := SlackAddBotUser(teamID, log)
diff --git a/api/slackimport_test.go b/api/slackimport_test.go
index d78424ac0..efe6e635f 100644
--- a/api/slackimport_test.go
+++ b/api/slackimport_test.go
@@ -217,3 +217,24 @@ func TestSlackSanitiseChannelProperties(t *testing.T) {
 		t.Fatalf("Unexpected alterations to the channel properties: %v", c2s.Header)
 	}
 }
+
+func TestSlackConvertPostsMarkup(t *testing.T) {
+	input := make(map[string][]SlackPost)
+	input["test"] = []SlackPost{
+		{
+			Text: "This message contains a link to <https://google.com|Google>.",
+		},
+		{
+			Text: "This message contains a mailto link to <mailto:me@example.com|me@example.com> in it.",
+		},
+	}
+
+	output := SlackConvertPostsMarkup(input)
+
+	if output["test"][0].Text != "This message contains a link to [Google](https://google.com)." {
+		t.Fatalf("Unexpected message after markup translation: %v", output["test"][0].Text)
+	}
+	if output["test"][1].Text != "This message contains a mailto link to [me@example.com](mailto:me@example.com) in it." {
+		t.Fatalf("Unexpected message after markup translation: %v", output["test"][0].Text)
+	}
+}