Merge queue support (#87)

* Add support for merge_queue events
* fix: merge-queue support (#85)
* Fix merge_group tests

---------

Co-authored-by: Victor Martinez <victormartinezrubio@gmail.com>

Author: mheap

index.js

@@ -27,6 +27,7 @@ async function action() {
 
     let providedLabels = core.getInput("labels", { required: true });
 
+    core.debug(`gather labels: ${providedLabels}`);
     if (labelsAreRegex) {
       // If labels are regex they must be provided as new line delimited
       providedLabels = providedLabels.split("\n");
@@ -43,6 +44,18 @@ async function action() {
     // Remove any empty labels
     providedLabels = providedLabels.filter((r) => r);
 
+    let issue_number = github.context.issue.number;
+
+    if (github.context.eventName === "merge_group" && !issue_number) {
+      // Parse out of the ref for merge queue
+      // e.g. refs/heads/gh-readonly-queue/main/pr-17-a3c310584587d4b97c2df0cb46fe050cc46a15d6
+      const lastPart = github.context.ref.split("/").pop();
+      issue_number = lastPart.match(/pr-(\d+)-/)[1];
+      core.info(
+        `merge_group event detected and issue_number parsed as ${issue_number}`,
+      );
+    }
+
     const allowedModes = ["exactly", "minimum", "maximum"];
     if (!allowedModes.includes(mode)) {
       await exitWithError(
@@ -52,6 +65,7 @@ async function action() {
         `Unknown mode input [${mode}]. Must be one of: ${allowedModes.join(
           ", ",
         )}`,
+        issue_number,
       );
       return;
     }
@@ -65,17 +79,18 @@ async function action() {
         `Unknown exit_code input [${exitType}]. Must be one of: ${allowedExitCodes.join(
           ", ",
         )}`,
+        issue_number,
       );
       return;
     }
 
-    // Fetch the labels using the API
+    core.debug(`fetch the labels for ${issue_number} using the API`);
     // We use the API rather than read event.json in case earlier steps
     // added a label
     const labels = (
       await octokit.rest.issues.listLabelsOnIssue({
         ...github.context.repo,
-        issue_number: github.context.issue.number,
+        issue_number,
       })
     ).data;
 
@@ -98,7 +113,7 @@ async function action() {
       );
     }
 
-    // Is there an error?
+    core.debug(`detect errors...`);
     let errorMode;
     if (mode === "exactly" && intersection.length !== count) {
       errorMode = "exactly";
@@ -108,7 +123,7 @@ async function action() {
       errorMode = "at most";
     }
 
-    // If so, add a comment (if enabled) and fail the run
+    core.debug(`if so, add a comment (if enabled) and fail the run...`);
     if (errorMode !== undefined) {
       const comment = core.getInput("message");
       const errorMessage = tmpl(comment, {
@@ -119,15 +134,21 @@ async function action() {
         applied: appliedLabels.join(", "),
       });
 
-      await exitWithError(exitType, octokit, shouldAddComment, errorMessage);
+      await exitWithError(
+        exitType,
+        octokit,
+        shouldAddComment,
+        errorMessage,
+        issue_number,
+      );
       return;
     }
 
-    // Remove the comment if it exists
+    core.debug(`remove the comment if it exists...`);
     if (shouldAddComment) {
       const { data: existing } = await octokit.rest.issues.listComments({
         ...github.context.repo,
-        issue_number: github.context.issue.number,
+        issue_number: issue_number,
       });
 
       const generatedComment = existing.find((c) =>
@@ -154,19 +175,25 @@ function tmpl(t, o) {
   });
 }
 
-async function exitWithError(exitType, octokit, shouldAddComment, message) {
+async function exitWithError(
+  exitType,
+  octokit,
+  shouldAddComment,
+  message,
+  issue_number,
+) {
   if (shouldAddComment) {
     // Is there an existing comment?
     const { data: existing } = await octokit.rest.issues.listComments({
       ...github.context.repo,
-      issue_number: github.context.issue.number,
+      issue_number: issue_number,
     });
 
     const generatedComment = existing.find((c) => c.body.includes(matchToken));
 
     const params = {
       ...github.context.repo,
-      issue_number: github.context.issue.number,
+      issue_number: issue_number,
       body: `${matchToken}${message}`,
     };
 

index.test.js

@@ -31,6 +31,7 @@ describe("Required Labels", () => {
     core.setOutput = jest.fn();
     core.warning = jest.fn();
     core.setFailed = jest.fn();
+    core.debug = jest.fn();
   });
 
   afterEach(() => {
@@ -645,6 +646,59 @@ describe("Required Labels", () => {
       await action();
     });
   });
+
+  describe("merge_group", () => {
+    it("extracts the PR number from the ref if needed", async () => {
+      restoreTest = mockEvent(
+        "merge_group",
+        {},
+        {
+          INPUT_LABELS: "enhancement",
+          INPUT_MODE: "exactly",
+          INPUT_COUNT: "1",
+          GITHUB_TOKEN: "mock-token-here-abc",
+        },
+        {
+          ref: "refs/heads/gh-readonly-queue/main/pr-28-a3c310584587d4b97c2df0cb46fe050cc46a15d6",
+        },
+      );
+
+      mockLabels(["enhancement", "bug"]);
+
+      await action();
+      expect(core.setOutput).toBeCalledTimes(2);
+      expect(core.setOutput).toBeCalledWith("status", "success");
+      expect(core.setOutput).toBeCalledWith("labels", "enhancement");
+    });
+
+    it("prefers the issue number that is set in the payload to extracting from a ref", async () => {
+      restoreTest = mockEvent(
+        "merge_group",
+        {
+          issue: {
+            number: 28,
+          },
+        },
+        {
+          INPUT_LABELS: "enhancement",
+          INPUT_MODE: "exactly",
+          INPUT_COUNT: "1",
+          GITHUB_TOKEN: "mock-token-here-abc",
+        },
+        {
+          // This would lead to an error as there are no mocks for PR 999
+          ref: "refs/heads/gh-readonly-queue/main/pr-999-a3c310584587d4b97c2df0cb46fe050cc46a15d6",
+        },
+      );
+
+      mockLabels(["enhancement", "bug"]);
+
+      await action();
+      expect(core.setOutput).toBeCalledTimes(2);
+      expect(core.setOutput).toBeCalledWith("status", "success");
+      expect(core.setOutput).toBeCalledWith("labels", "enhancement");
+    });
+  });
 });
 
 function mockPr(env) {
@@ -683,8 +737,18 @@ function mockListComments(comments) {
     );
 }
 
-function mockEvent(eventName, mockPayload, additionalParams = {}) {
+function mockEvent(
+  eventName,
+  mockPayload,
+  additionalParams,
+  additionalContext = {},
+) {
   github.context.payload = mockPayload;
+  github.context.eventName = eventName;
+
+  for (const key in additionalContext) {
+    github.context[key] = additionalContext[key];
+  }
 
   const params = {
     GITHUB_EVENT_NAME: eventName,