Fix #2867: Add support for GET /feed/{id}

catalog-rest-service/src/main/java/org/openmetadata/catalog/jdbi3/FeedRepository.java

@@ -185,6 +185,11 @@ public ThreadCount getThreadsCount(String link, boolean isResolved) throws IOExc
     return threadCount;
   }
 
+  public List<Post> listPosts(String threadId) throws IOException {
+    Thread thread = get(threadId);
+    return thread.getPosts();
+  }
+
   @Transaction
   public List<Thread> listThreads(String link) throws IOException {
     if (link == null) {

catalog-rest-service/src/main/java/org/openmetadata/catalog/resources/feeds/FeedResource.java

@@ -20,6 +20,8 @@
 import io.swagger.v3.oas.annotations.media.Schema;
 import io.swagger.v3.oas.annotations.responses.ApiResponse;
 import java.io.IOException;
+import java.io.UnsupportedEncodingException;
+import java.security.GeneralSecurityException;
 import java.text.ParseException;
 import java.util.List;
 import java.util.Objects;
@@ -83,6 +85,20 @@ static class ThreadList extends ResultList<Thread> {
     }
   }
 
+  public static class PostList extends ResultList<Post> {
+    @SuppressWarnings("unused") /* Required for tests */
+    public PostList() {}
+
+    public PostList(List<Post> data, String beforeCursor, String afterCursor, int total)
+        throws GeneralSecurityException, UnsupportedEncodingException {
+      super(data, beforeCursor, afterCursor, total);
+    }
+
+    public PostList(List<Post> listPosts) {
+      super(listPosts);
+    }
+  }
+
   @GET
   @Operation(
       summary = "List threads",
@@ -187,6 +203,22 @@ public Response addPost(@Context UriInfo uriInfo, @PathParam("id") String id, @V
     return Response.created(thread.getHref()).entity(thread).build();
   }
 
+  @GET
+  @Path("/{id}/posts")
+  @Operation(
+      summary = "Get all the posts of a thread",
+      tags = "feeds",
+      description = "Get all the posts of an existing thread.",
+      responses = {
+        @ApiResponse(
+            responseCode = "200",
+            description = "The posts of the given thread.",
+            content = @Content(mediaType = "application/json", schema = @Schema(implementation = PostList.class))),
+      })
+  public PostList getPosts(@Context UriInfo uriInfo, @PathParam("id") String id) throws IOException {
+    return new PostList(dao.listPosts(id));
+  }
+
   private Thread getThread(SecurityContext securityContext, CreateThread create) {
     return new Thread()
         .withId(UUID.randomUUID())

catalog-rest-service/src/test/java/org/openmetadata/catalog/resources/feeds/FeedResourceTest.java

@@ -50,6 +50,7 @@
 import org.openmetadata.catalog.entity.teams.Team;
 import org.openmetadata.catalog.entity.teams.User;
 import org.openmetadata.catalog.resources.databases.TableResourceTest;
+import org.openmetadata.catalog.resources.feeds.FeedResource.PostList;
 import org.openmetadata.catalog.resources.feeds.FeedResource.ThreadList;
 import org.openmetadata.catalog.type.Column;
 import org.openmetadata.catalog.type.ColumnDataType;
@@ -234,10 +235,25 @@ void post_addPostWithNonExistentFrom_404() {
   void post_validAddPost_200() throws HttpResponseException {
     Thread thread = createAndCheck(create(), AUTH_HEADERS);
     // Add 10 posts and validate
-    for (int i = 0; i < 10; i++) {
+    int POST_COUNT = 10;
+    for (int i = 0; i < POST_COUNT; i++) {
       Post post = createPost();
       thread = addPostAndCheck(thread, post, AUTH_HEADERS);
     }
+
+    // Check if get posts API returns all the posts
+    PostList postList = listPosts(thread.getId().toString(), AUTH_HEADERS);
+    // Thread also has the first message as a post.
+    // So, the total count should be POST_COUNT+1
+    assertEquals(POST_COUNT + 1, postList.getData().size());
+  }
+
+  @Test
+  void get_listPosts_404() {
+    assertResponse(
+        () -> listPosts(NON_EXISTENT_ENTITY.toString(), AUTH_HEADERS),
+        NOT_FOUND,
+        entityNotFound("Thread", NON_EXISTENT_ENTITY));
   }
 
   public static Thread createAndCheck(CreateThread create, Map<String, String> authHeaders)
@@ -311,6 +327,11 @@ public static ThreadList listThreads(String entityLink, Map<String, String> auth
     return TestUtils.get(target, ThreadList.class, authHeaders);
   }
 
+  public static PostList listPosts(String threadId, Map<String, String> authHeaders) throws HttpResponseException {
+    WebTarget target = getResource(String.format("feed/%s/posts", threadId));
+    return TestUtils.get(target, PostList.class, authHeaders);
+  }
+
   public static ThreadCount listThreadsCount(String entityLink, Map<String, String> authHeaders)
       throws HttpResponseException {
     WebTarget target = getResource("feed/count");
@@ -322,6 +343,6 @@ private int getThreadCount(String entityLink, Map<String, String> authHeaders) t
     List<EntityLinkThreadCount> linkThreadCount = listThreadsCount(entityLink, authHeaders).getCounts();
     EntityLinkThreadCount threadCount =
         linkThreadCount.stream().filter(l -> l.getEntityLink().equals(entityLink)).findFirst().orElseThrow();
-    return (int) threadCount.getCount();
+    return threadCount.getCount();
   }
 }