feat: add issue reaction methods and fix comment reaction template

- Add createIssueReaction() and deleteIssueReaction() methods
- Fix COMMENTS_REACTION_ID_TEMPLATE to use correct comment endpoint
- Add comprehensive tests for issue reaction functionality
- Update deleteCommentReaction method signature to use commentId

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>

Author: javoire

src/main/java/com/spotify/github/v3/clients/IssueClient.java

@@ -43,7 +43,9 @@ public class IssueClient {
   static final String COMMENTS_URI_TEMPLATE = "/repos/%s/%s/issues/comments";
   static final String COMMENTS_URI_ID_TEMPLATE = "/repos/%s/%s/issues/comments/%s";
   static final String COMMENTS_REACTION_TEMPLATE = "/repos/%s/%s/issues/comments/%s/reactions";
-  static final String COMMENTS_REACTION_ID_TEMPLATE = "/repos/%s/%s/issues/%s/reactions/%s";
+  static final String COMMENTS_REACTION_ID_TEMPLATE = "/repos/%s/%s/issues/comments/%s/reactions/%s";
+  static final String ISSUES_REACTION_TEMPLATE = "/repos/%s/%s/issues/%s/reactions";
+  static final String ISSUES_REACTION_ID_TEMPLATE = "/repos/%s/%s/issues/%s/reactions/%s";
   static final String ISSUES_URI_ID_TEMPLATE = "/repos/%s/%s/issues/%s";
   private static final Logger log = LoggerFactory.getLogger(MethodHandles.lookup().lookupClass());
 
@@ -53,7 +55,6 @@ public class IssueClient {
 
   /**
    * Constructs an IssueClient.
-   *
    * @param github the GitHub client
    * @param owner the repository owner
    * @param repo the repository name
@@ -260,14 +261,14 @@ public CompletableFuture<CommentReaction> createCommentReaction(
    * href="https://docs.github.com/en/rest/reactions/reactions?apiVersion=2022-11-28#delete-an-issue-comment-reaction">List
    * reactions for an issue comment</a>
    *
-   * @param issueNumber the issue number
+   * @param commentId the comment id
    * @param reactionId the reaction id
    * @return a CompletableFuture containing the HTTP response
    */
   public CompletableFuture<HttpResponse> deleteCommentReaction(
-      final long issueNumber, final long reactionId) {
+      final long commentId, final long reactionId) {
     final String path =
-        String.format(COMMENTS_REACTION_ID_TEMPLATE, owner, repo, issueNumber, reactionId);
+        String.format(COMMENTS_REACTION_ID_TEMPLATE, owner, repo, commentId, reactionId);
     return github.delete(path);
   }
 
@@ -284,4 +285,35 @@ public GithubPageIterator<CommentReaction> listCommentReaction(final long commen
     return new GithubPageIterator<>(
         new GithubPage<>(github, path, LIST_COMMENT_REACTION_TYPE_REFERENCE));
   }
+
+  /**
+   * Creates a reaction on an issue.
+   *
+   * @param issueNumber the issue number
+   * @param reaction the reaction content
+   * @return a CompletableFuture containing the created reaction
+   */
+  public CompletableFuture<CommentReaction> createIssueReaction(
+      final long issueNumber, final CommentReactionContent reaction) {
+    final String path = String.format(ISSUES_REACTION_TEMPLATE, owner, repo, issueNumber);
+    final String requestBody =
+        github.json().toJsonUnchecked(ImmutableMap.of("content", reaction.toString()));
+    return github.post(path, requestBody, CommentReaction.class);
+  }
+
+  /**
+   * Deletes a reaction on an issue. See <a
+   * href="https://docs.github.com/en/rest/reactions/reactions?apiVersion=2022-11-28#delete-an-issue-reaction">Delete
+   * an issue reaction</a>
+   *
+   * @param issueNumber the issue number
+   * @param reactionId the reaction id
+   * @return a CompletableFuture containing the HTTP response
+   */
+  public CompletableFuture<HttpResponse> deleteIssueReaction(
+      final long issueNumber, final long reactionId) {
+    final String path =
+        String.format(ISSUES_REACTION_ID_TEMPLATE, owner, repo, issueNumber, reactionId);
+    return github.delete(path);
+  }
 }

src/test/java/com/spotify/github/v3/clients/IssueClientTest.java

@@ -217,15 +217,15 @@ public void testCreateIssueCommentReaction(CommentReactionContent reaction) {
 
   @Test
   public void testDeleteIssueCommentReaction() {
-    long issueNumber = 42;
+    long commentId = 42;
     long reactionId = 385825;
     final String path =
-        format(COMMENTS_REACTION_ID_TEMPLATE, "someowner", "somerepo", issueNumber, reactionId);
+        format(COMMENTS_REACTION_TEMPLATE + "/%s", "someowner", "somerepo", commentId, reactionId);
     HttpResponse mockResponse = mock(HttpResponse.class);
     when(mockResponse.statusCode()).thenReturn(204);
     when(github.delete(eq(path))).thenReturn(completedFuture(mockResponse));
 
-    final var response = issueClient.deleteCommentReaction(issueNumber, reactionId).join();
+    final var response = issueClient.deleteCommentReaction(commentId, reactionId).join();
 
     assertThat(response.statusCode(), is(204));
     assertThat(response, is(mockResponse));
@@ -271,6 +271,49 @@ public void testListIssueCommentReaction() throws IOException {
     verify(github, atLeastOnce()).request(eq(path));
   }
 
+  @ParameterizedTest
+  @EnumSource(CommentReactionContent.class)
+  public void testCreateIssueReaction(CommentReactionContent reaction) {
+    long issueNumber = 42;
+    final CompletableFuture<CommentReaction> reactionResponse =
+        completedFuture(
+            ImmutableCommentReaction.builder()
+                .id(123L)
+                .content(reaction)
+                .user(ImmutableUser.builder().login("octocat").build())
+                .build());
+    final String path = format(ISSUES_REACTION_TEMPLATE, "someowner", "somerepo", issueNumber);
+    final String requestBody =
+        github.json().toJsonUnchecked(ImmutableMap.of("content", reaction.toString()));
+    when(github.post(eq(path), eq(requestBody), eq(CommentReaction.class)))
+        .thenReturn(reactionResponse);
+
+    final var issueReaction = issueClient.createIssueReaction(issueNumber, reaction).join();
+
+    assertThat(issueReaction.id(), is(123L));
+    assertNotNull(issueReaction.user());
+    assertThat(issueReaction.user().login(), is("octocat"));
+    assertThat(issueReaction.content().toString(), is(reaction.toString()));
+    verify(github, times(1)).post(eq(path), eq(requestBody), eq(CommentReaction.class));
+  }
+
+  @Test
+  public void testDeleteIssueReaction() {
+    long issueNumber = 42;
+    long reactionId = 385825;
+    final String path =
+        format(ISSUES_REACTION_ID_TEMPLATE, "someowner", "somerepo", issueNumber, reactionId);
+    HttpResponse mockResponse = mock(HttpResponse.class);
+    when(mockResponse.statusCode()).thenReturn(204);
+    when(github.delete(eq(path))).thenReturn(completedFuture(mockResponse));
+
+    final var response = issueClient.deleteIssueReaction(issueNumber, reactionId).join();
+
+    assertThat(response.statusCode(), is(204));
+    assertThat(response, is(mockResponse));
+    verify(github, times(1)).delete(eq(path));
+  }
+
   @Test
   public void testGetIssueNoIssue() {
     final String path = format(ISSUES_URI_ID_TEMPLATE, "someowner", "somerepo", 2);