Only use fallback for refs if ref is not found

Fallbacks in messages are not changed when channels/users/groups are
renamed, so they shouldn't be used unless the ref can't be found. Links
are not refs we look up, so they are still treated the same way.

2 files changed, 53 insertions, 39 deletions

diff --git a/_pytest/test_unfurl.py b/_pytest/test_unfurl.py
index 6178bbb..fe1fc3d 100644
--- a/_pytest/test_unfurl.py
+++ b/_pytest/test_unfurl.py
@@ -28,23 +28,38 @@ import pytest
     {
         'input': "<@U407ABLLW|@othernick>: foo",
         'output': "@alice: foo",
-        'ignore_alt_text': True,
+    },
+    {
+        'input': "<@UNKNOWN|@othernick>: foo",
+        'output': "@othernick: foo",
     },
     {
         'input': "foo <#C407ABS94|otherchannel> foo",
+        'output': "foo #general foo",
+    },
+    {
+        'input': "foo <#UNKNOWN|otherchannel> foo",
         'output': "foo #otherchannel foo",
     },
     {
-        'input': "foo <#C407ABS94> foo",
-        'output': "foo #general foo",
+        'input': "url: <https://example.com|fallback> suffix",
+        'output': "url: https://example.com suffix",
+        'ignore_alt_text': True,
     },
     {
         'input': "url: <https://example.com|example> suffix",
         'output': "url: https://example.com (example) suffix",
+        'auto_link_display': 'both',
     },
     {
         'input': "url: <https://example.com|example with spaces> suffix",
         'output': "url: https://example.com (example with spaces) suffix",
+        'auto_link_display': 'both',
+    },
+    {
+        'input': "url: <https://example.com|example.com> suffix",
+        'output': "url: https://example.com (example.com) suffix",
+        'auto_link_display': 'both',
     },
     {
         'input': "url: <https://example.com|example.com> suffix",
@@ -67,8 +82,9 @@ import pytest
         'auto_link_display': 'url',
     },
     {
-        'input': "<@U407ABLLW|@othernick> multiple unfurl <https://example.com|example with spaces>",
-        'output': "@othernick multiple unfurl https://example.com (example with spaces)",
+        'input': "<@U407ABLLW> multiple unfurl <https://example.com|example with spaces>",
+        'output': "@alice multiple unfurl https://example.com (example with spaces)",
+        'auto_link_display': 'both',
     },
     {
         'input': "try the #general channel",
@@ -79,8 +95,12 @@ import pytest
         'output': "@alice I think 3 > 2",
     },
     {
-        'input': "<!subteam^U407ABLLW|@dev> This is announcement for the dev team",
-        'output': "@dev This is announcement for the dev team"
+        'input': "<!subteam^TGX0ALBK3|@othersubteam> This is announcement for the dev team",
+        'output': "@test This is announcement for the dev team"
+    },
+    {
+        'input': "<!subteam^UNKNOWN|@othersubteam> This is announcement for the dev team",
+        'output': "@othersubteam This is announcement for the dev team"
     }
 ))
 def test_unfurl_refs(case, realish_eventrouter):
diff --git a/wee_slack.py b/wee_slack.py
index b081a03..0e08ef5 100644
--- a/wee_slack.py
+++ b/wee_slack.py
@@ -3434,38 +3434,32 @@ def unfurl_refs(text):
     # Test patterns lives in ./_pytest/test_unfurl.py
 
     def unfurl_ref(match):
-        ref = match.group(1)
-        id = ref.split('|')[0]
-        display_text = ref
-        if ref.find('|') > -1:
-            if config.unfurl_ignore_alt_text:
-                display_text = resolve_ref(id)
+        ref, fallback = match.groups()
+
+        resolved_ref = resolve_ref(ref)
+        if resolved_ref != ref:
+            return resolved_ref
+
+        if fallback and not config.unfurl_ignore_alt_text:
+            if ref.startswith("#"):
+                return "#{}".format(fallback)
+            elif ref.startswith("@"):
+                return fallback
+            elif ref.startswith("!subteam"):
+                prefix = "@" if not fallback.startswith("@") else ""
+                return prefix + fallback
             else:
-                if id.startswith("#"):
-                    display_text = "#{}".format(ref.split('|')[1])
-                elif id.startswith("@"):
-                    display_text = ref.split('|')[1]
-                elif id.startswith("!subteam"):
-                    if ref.split('|')[1].startswith('@'):
-                        handle = ref.split('|')[1][1:]
-                    else:
-                        handle = ref.split('|')[1]
-                    display_text = '@{}'.format(handle)
+                match_url = r"^\w+:(//)?{}$".format(re.escape(fallback))
+                url_matches_desc = re.match(match_url, ref)
+                if url_matches_desc and config.unfurl_auto_link_display == "text":
+                    return fallback
+                elif url_matches_desc and config.unfurl_auto_link_display == "url":
+                    return ref
                 else:
-                    url, desc = ref.split('|', 1)
-                    match_url = r"^\w+:(//)?{}$".format(re.escape(desc))
-                    url_matches_desc = re.match(match_url, url)
-                    if url_matches_desc and config.unfurl_auto_link_display == "text":
-                        display_text = desc
-                    elif url_matches_desc and config.unfurl_auto_link_display == "url":
-                        display_text = url
-                    else:
-                        display_text = "{} ({})".format(url, desc)
-        else:
-            display_text = resolve_ref(ref)
-        return display_text
+                    return "{} ({})".format(ref, fallback)
+        return ref
 
-    return re.sub(r"<([@#!]?[^>]*)>", unfurl_ref, text)
+    return re.sub(r"<([^|>]*)(?:\|([^>]*))?>", unfurl_ref, text)
 
 
 def unhtmlescape(text):
@@ -3549,10 +3543,10 @@ def unwrap_files(message_json, text_before):
 
 
 def resolve_ref(ref):
+    if ref in ['!channel', '!everyone', '!group', '!here']:
+        return ref.replace('!', '@')
     for team in EVENTROUTER.teams.values():
-        if ref in ['!channel', '!everyone', '!group', '!here']:
-            return ref.replace('!', '@')
-        elif ref.startswith('@'):
+        if ref.startswith('@'):
             user = team.users.get(ref[1:])
             if user:
                 suffix = config.external_user_suffix if user.is_external else ''