720: Incorrect usage instructions for label command

Reviewed-by: rwestberg

bots/pr/src/main/java/org/openjdk/skara/bots/pr/LabelerWorkItem.java

@@ -73,33 +73,39 @@ private void updateLabelMessage(List<Comment> comments, List<String> newLabels)
         if (newLabels.isEmpty()) {
             message.append("To determine the appropriate audience for reviewing this pull request, one or more ");
             message.append("labels corresponding to different subsystems will normally be applied automatically. ");
-            message.append("However, no automatic labelling rule matches the changes in this pull request.\n\n");
-            message.append("In order to have an RFR email automatically sent to the correct mailing list, you will ");
-            message.append("need to add one or more labels manually using the `/label add \"label\"` command. ");
-            message.append("The following labels are valid: ");
-            var labels = bot.labelConfiguration().allowed().stream()
-                            .sorted()
-                            .map(label -> "`" + label + "`")
-                            .collect(Collectors.joining(" "));
-            message.append(labels);
-            message.append(".");
+            message.append("However, no automatic labelling rule matches the changes in this pull request. ");
+            message.append("In order to have an \"RFR\" email sent to the correct mailing list, you will ");
+            message.append("need to add one or more applicable labels manually using the ");
+            message.append("[/label](https://wiki.openjdk.java.net/display/SKARA/Pull+Request+Commands#PullRequestCommands-/label)");
+            message.append(" pull request command.\n\n");
+            message.append("<details>\n");
+            message.append("<summary>Applicable Labels</summary>\n");
+            message.append("<br>\n");
+            message.append("\n");
+            bot.labelConfiguration().allowed()
+                                    .stream()
+                                    .sorted()
+                                    .forEach(label -> message.append("- `" + label + "`\n"));
+            message.append("\n");
+            message.append("</details>");
         } else {
             message.append("The following label");
             if (newLabels.size() > 1) {
                 message.append("s");
             }
-            message.append(" will be automatically applied to this pull request: ");
-            var labels = newLabels.stream()
-                                  .sorted()
-                                  .map(label -> "`" + label + "`")
-                                  .collect(Collectors.joining(" "));
-            message.append(labels);
-            message.append(".\n\nWhen this pull request is ready to be reviewed, an RFR email will be sent to the ");
+            message.append(" will be automatically applied to this pull request:\n\n");
+            newLabels.stream()
+                     .sorted()
+                     .forEach(label -> message.append("- `" + label + "`\n"));
+            message.append("\n");
+            message.append("When this pull request is ready to be reviewed, an \"RFR\" email will be sent to the ");
             message.append("corresponding mailing list");
             if (newLabels.size() > 1) {
                 message.append("s");
             }
-            message.append(". If you would like to change these labels, use the `/label (add|remove) \"label\"` command.");
+            message.append(". If you would like to change these labels, use the ");
+            message.append("[/label](https://wiki.openjdk.java.net/display/SKARA/Pull+Request+Commands#PullRequestCommands-/label)");
+            message.append(" pull request command.");
         }
 
         message.append("\n");

bots/pr/src/test/java/org/openjdk/skara/bots/pr/LabelerTests.java

@@ -71,7 +71,11 @@ void simple(TestInfo testInfo) throws IOException {
             TestBotRunner.runPeriodicItems(labelBot);
             assertEquals(Set.of("rfr"), new HashSet<>(pr.labels()));
             assertLastCommentContains(pr, "However, no automatic labelling rule matches the changes in this pull request.");
-            assertLastCommentContains(pr, "The following labels are valid: `test1` `test2`");
+            assertLastCommentContains(pr, "<details>");
+            assertLastCommentContains(pr, "<summary>Applicable Labels</summary>");
+            assertLastCommentContains(pr, "- `test1`");
+            assertLastCommentContains(pr, "- `test2`");
+            assertLastCommentContains(pr, "</details>");
 
             var fileA = localRepoFolder.resolve("a.txt");
             Files.writeString(fileA, "Hello");