Use issues endpoint to react on pull requests

Pull requests are sorta issues and for reactions, you need to use the
issues API to react.

Fixes #1749

Author: gsmet

src/main/java/org/kohsuke/github/GHIssue.java

@@ -590,7 +590,7 @@ public GHReaction createReaction(ReactionContent content) throws IOException {
                 .method("POST")
                 .withPreview(SQUIRREL_GIRL)
                 .with("content", content.getContent())
-                .withUrlPath(getApiRoute() + "/reactions")
+                .withUrlPath(getIssuesApiRoute() + "/reactions")
                 .fetch(GHReaction.class);
     }
 
@@ -606,7 +606,7 @@ public void deleteReaction(GHReaction reaction) throws IOException {
         owner.root()
                 .createRequest()
                 .method("DELETE")
-                .withUrlPath(getApiRoute(), "reactions", String.valueOf(reaction.getId()))
+                .withUrlPath(getIssuesApiRoute(), "reactions", String.valueOf(reaction.getId()))
                 .send();
     }
 
@@ -619,7 +619,7 @@ public void deleteReaction(GHReaction reaction) throws IOException {
     public PagedIterable<GHReaction> listReactions() {
         return root().createRequest()
                 .withPreview(SQUIRREL_GIRL)
-                .withUrlPath(getApiRoute() + "/reactions")
+                .withUrlPath(getIssuesApiRoute() + "/reactions")
                 .toIterable(GHReaction[].class, null);
     }
 

src/test/java/org/kohsuke/github/GHPullRequestTest.java

@@ -883,6 +883,26 @@ public void checkPullRequestReviewer() throws IOException {
         assertThat(reviewer, notNullValue());
     }
 
+    /**
+     * Create/Delete reaction for pull requests.
+     *
+     * @throws Exception
+     *             the exception
+     */
+    @Test
+    public void reactions() throws Exception {
+        String name = "createPullRequest";
+        GHRepository repo = getRepository();
+        GHPullRequest p = repo.createPullRequest(name, "test/stable", "main", "## test");
+
+        assertThat(p.listReactions().toList(), hasSize(0));
+        GHReaction reaction = p.createReaction(ReactionContent.CONFUSED);
+        assertThat(p.listReactions().toList(), hasSize(1));
+
+        p.deleteReaction(reaction);
+        assertThat(p.listReactions().toList(), hasSize(0));
+    }
+
     /**
      * Gets the repository.
      *

src/test/resources/org/kohsuke/github/GHPullRequestTest/wiremock/reactions/__files/1-orgs_hub4j-test-org.json

@@ -0,0 +1,66 @@
+{
+  "login": "hub4j-test-org",
+  "id": 7544739,
+  "node_id": "MDEyOk9yZ2FuaXphdGlvbjc1NDQ3Mzk=",
+  "url": "https://api.github.com/orgs/hub4j-test-org",
+  "repos_url": "https://api.github.com/orgs/hub4j-test-org/repos",
+  "events_url": "https://api.github.com/orgs/hub4j-test-org/events",
+  "hooks_url": "https://api.github.com/orgs/hub4j-test-org/hooks",
+  "issues_url": "https://api.github.com/orgs/hub4j-test-org/issues",
+  "members_url": "https://api.github.com/orgs/hub4j-test-org/members{/member}",
+  "public_members_url": "https://api.github.com/orgs/hub4j-test-org/public_members{/member}",
+  "avatar_url": "https://avatars.githubusercontent.com/u/7544739?v=4",
+  "description": "Hub4j Test Org Description (this could be null or blank too)",
+  "name": "Hub4j Test Org Name (this could be null or blank too)",
+  "company": null,
+  "blog": "https://hub4j.url.io/could/be/null",
+  "location": "Hub4j Test Org Location (this could be null or blank too)",
+  "email": "[email protected]",
+  "twitter_username": null,
+  "is_verified": false,
+  "has_organization_projects": true,
+  "has_repository_projects": true,
+  "public_repos": 26,
+  "public_gists": 0,
+  "followers": 2,
+  "following": 0,
+  "html_url": "https://github.com/hub4j-test-org",
+  "created_at": "2014-05-10T19:39:11Z",
+  "updated_at": "2020-06-04T05:56:10Z",
+  "archived_at": null,
+  "type": "Organization",
+  "total_private_repos": 6,
+  "owned_private_repos": 6,
+  "private_gists": 0,
+  "disk_usage": 12014,
+  "collaborators": 1,
+  "billing_email": "[email protected]",
+  "default_repository_permission": "none",
+  "members_can_create_repositories": false,
+  "two_factor_requirement_enabled": false,
+  "members_allowed_repository_creation_type": "none",
+  "members_can_create_public_repositories": false,
+  "members_can_create_private_repositories": false,
+  "members_can_create_internal_repositories": false,
+  "members_can_create_pages": true,
+  "members_can_fork_private_repositories": false,
+  "web_commit_signoff_required": false,
+  "members_can_create_public_pages": true,
+  "members_can_create_private_pages": true,
+  "plan": {
+    "name": "free",
+    "space": 976562499,
+    "private_repos": 10000,
+    "filled_seats": 50,
+    "seats": 3
+  },
+  "advanced_security_enabled_for_new_repositories": false,
+  "dependabot_alerts_enabled_for_new_repositories": false,
+  "dependabot_security_updates_enabled_for_new_repositories": false,
+  "dependency_graph_enabled_for_new_repositories": false,
+  "secret_scanning_enabled_for_new_repositories": false,
+  "secret_scanning_push_protection_enabled_for_new_repositories": false,
+  "secret_scanning_push_protection_custom_link_enabled": false,
+  "secret_scanning_push_protection_custom_link": null,
+  "secret_scanning_validity_checks_enabled": false
+}