add logic to store github labeled webhook event to DynamoDB (#6497)

only merge this after
meta-pytorch/pytorch-gha-infra#646 has been
merged & deployed

Goal is to keep track of when issues are labeled or unlabeled for
statistics purposes.


Test plan: 
- added unit test to test double Dynamo update

Author: wdvr

torchci/lib/bot/webhookToDynamo.ts

@@ -35,16 +35,37 @@ async function handleWorkflowJob(
 }
 
 async function handleIssues(event: Context<"issues">) {
-  const key_prefix = event.payload.repository.full_name + "/";
   const client = getDynamoClient();
 
+  const issue_number = event.payload.issue.number;
+  const repo_name = event.payload.repository.full_name;
+
   await client.put({
     TableName: "torchci-issues",
     Item: {
-      dynamoKey: `${key_prefix}${event.payload.issue.number}`,
+      dynamoKey: `${repo_name}/${event.payload.issue.number}`,
       ...event.payload.issue,
     },
   });
+
+  if (
+    event.payload.action === "labeled" ||
+    event.payload.action === "unlabeled"
+  ) {
+    const datetime = event.payload.issue.updated_at;
+    const label_name = event.payload.label?.name;
+    await client.put({
+      TableName: "torchci-issues-label-event",
+      Item: {
+        dynamoKey: `${repo_name}/${issue_number}-${label_name}`,
+        repo_name: repo_name,
+        issue_number: issue_number,
+        event_time: datetime,
+        label_name: label_name,
+        action: event.payload.action,
+      },
+    });
+  }
 }
 
 async function handleIssueComment(event: Context<"issue_comment">) {

torchci/test/fixtures/webhookToDynamoExpected.json.gz

@@ -46,10 +46,12 @@ describe("webhookToDynamo tests", () => {
    * "workflow_job".  This is the X-GitHub-Event header.  Files that take the
    * form {"name": something, "id": something, "payload": something} should not
    * include this.
+   * @param dynamo_call_count Number of times to call the dynamo client. Defaults to 1.
    */
   async function helper(
     filename: string,
-    name: string | undefined = undefined
+    name: string | undefined = undefined,
+    dynamo_call_count: number = 1
   ) {
     const event = requireDeepCopy(filename);
     const mockedPut = jest.fn();
@@ -61,7 +63,7 @@ describe("webhookToDynamo tests", () => {
     } else {
       await probot.receive(event);
     }
-    expect(mockedPut.mock.calls.length).toBe(1);
+    expect(mockedPut.mock.calls.length).toBe(dynamo_call_count);
     const body = mockedPut.mock.calls[0];
     saveResult(filename, body);
     expect(body).toEqual(expectedResults[filename]);
@@ -94,4 +96,9 @@ describe("webhookToDynamo tests", () => {
   test("pull_request_comment", async () => {
     await helper("./fixtures/pull_request_comment.json");
   });
+
+  test("issue_labeled", async () => {
+    // expecting 2 calls, one for updating the issue and one for the labeled event
+    await helper("./fixtures/issues.labeled.json", "issues", 2);
+  });
 });