slack: don't link to compare for 1-commit push

Author: yasunariw

lib/slack.ml

@@ -230,6 +230,12 @@ let generate_push_notification notification channel =
   let commits_branch = Github.commits_branch_of_ref notification.ref in
   let tree_url = String.concat ~sep:"/" [ repository.url; "tree"; Uri.pct_encode commits_branch ] in
   let num_commits = List.length commits in
+  let compare =
+    (* if single commit, don't show compare *)
+    match commits with
+    | [ { url; _ } ] -> url
+    | _ -> compare
+  in
   let title =
     if deleted then
       sprintf "<%s|[%s]> %s deleted branch <%s|%s>" tree_url repository.name sender.login compare commits_branch

test/slack_payloads.expected

@@ -455,7 +455,7 @@ will notify #backend1
 {
   "channel": "backend1",
   "text":
-    "<https://github.com/octocat/test-repo/tree/develop|[test-repo:develop]> <https://github.com/octocat/test-repo/compare/fb245e2a6d52...e2173f38ae43|1 commit> pushed by octocat",
+    "<https://github.com/octocat/test-repo/tree/develop|[test-repo:develop]> <https://github.com/octocat/test-repo/commit/80452f696a8988e7234063d47720a62e902f2afc|1 commit> pushed by octocat",
   "attachments": [
     {
       "fallback": "Commit pushed notification",
@@ -475,7 +475,7 @@ will notify #backend1
 {
   "channel": "backend1",
   "text":
-    "<https://github.com/octocat/test-repo/tree/master|[test-repo:master]> <https://github.com/octocat/test-repo/compare/fb245e2a6d52...e2173f38ae43|1 commit> pushed by octocat",
+    "<https://github.com/octocat/test-repo/tree/master|[test-repo:master]> <https://github.com/octocat/test-repo/commit/80452f696a8988e7234063d47720a62e902f2afc|1 commit> pushed by octocat",
   "attachments": [
     {
       "fallback": "Commit pushed notification",
@@ -514,7 +514,7 @@ will notify #default
 {
   "channel": "default",
   "text":
-    "<https://github.com/octocat/test-repo/tree/feature%2Ff1|[test-repo:feature/f1]> <https://github.com/octocat/test-repo/compare/fb245e2a6d52...e2173f38ae43|1 commit> pushed by octocat",
+    "<https://github.com/octocat/test-repo/tree/feature%2Ff1|[test-repo:feature/f1]> <https://github.com/octocat/test-repo/commit/80452f696a8988e7234063d47720a62e902f2afc|1 commit> pushed by octocat",
   "attachments": [
     {
       "fallback": "Commit pushed notification",
@@ -573,7 +573,7 @@ will notify #longest-a1
 {
   "channel": "longest-a1",
   "text":
-    "<https://github.com/thatportugueseguy/monorepo/tree/develop|[monorepo:develop]> <https://github.com/thatportugueseguy/monorepo/compare/fb245e2a6d52...e2173f38ae43|1 commit> pushed by thatportugueseguy",
+    "<https://github.com/thatportugueseguy/monorepo/tree/develop|[monorepo:develop]> <https://github.com/thatportugueseguy/monorepo/commit/e2173f38ae43865433a182c1fc1b5442d9763b54|1 commit> pushed by thatportugueseguy",
   "attachments": [
     {
       "fallback": "Commit pushed notification",