feat(bot): add bot_ci merge blocking check

apps/bot/src/index.ts

@@ -1,5 +1,7 @@
 import { ApplicationFunctionOptions, Probot } from "probot";
 
+import { registerMergeableHandlers } from "./mergeable.js";
+
 export default (app: Probot, { getRouter }: ApplicationFunctionOptions) => {
   if (getRouter) {
     const router = getRouter("/");
@@ -9,6 +11,8 @@ export default (app: Probot, { getRouter }: ApplicationFunctionOptions) => {
     });
   }
 
+  registerMergeableHandlers(app);
+
   app.on("issues.opened", async (context) => {
     const issueComment = context.issue({
       body: "Thanks for opening this issue!",

apps/bot/src/mergeable.ts

@@ -0,0 +1,185 @@
+import { Probot } from "probot";
+
+const BOT_CI_CHECK_NAME = "bot_ci";
+const MERGEABLE_CHECK_NAME = "Mergeable: bot_ci";
+
+interface CheckRun {
+  id: number;
+  name: string;
+  status: string;
+  conclusion: string | null;
+}
+
+type ProbotContext = Parameters<Parameters<Probot["on"]>[1]>[0];
+
+async function getBotCiCheckRun(
+  context: ProbotContext,
+  owner: string,
+  repo: string,
+  ref: string,
+): Promise<CheckRun | null> {
+  const { data } = await context.octokit.checks.listForRef({
+    owner,
+    repo,
+    ref,
+    check_name: BOT_CI_CHECK_NAME,
+  });
+
+  if (data.check_runs.length === 0) {
+    return null;
+  }
+
+  const checkRun = data.check_runs[0];
+  return {
+    id: checkRun.id,
+    name: checkRun.name,
+    status: checkRun.status,
+    conclusion: checkRun.conclusion,
+  };
+}
+
+async function createOrUpdateMergeableCheck(
+  context: ProbotContext,
+  owner: string,
+  repo: string,
+  headSha: string,
+  botCiCheck: CheckRun | null,
+): Promise<void> {
+  const existingChecks = await context.octokit.checks.listForRef({
+    owner,
+    repo,
+    ref: headSha,
+    check_name: MERGEABLE_CHECK_NAME,
+  });
+
+  let status: "queued" | "in_progress" | "completed";
+  let conclusion:
+    | "success"
+    | "failure"
+    | "neutral"
+    | "cancelled"
+    | "skipped"
+    | "timed_out"
+    | "action_required"
+    | undefined;
+  let title: string;
+  let summary: string;
+
+  if (botCiCheck === null) {
+    status = "completed";
+    conclusion = "success";
+    title = "bot_ci not triggered";
+    summary =
+      "The bot_ci check was not triggered for this PR, so merging is allowed.";
+  } else if (botCiCheck.status !== "completed") {
+    status = "in_progress";
+    conclusion = undefined;
+    title = "Waiting for bot_ci to complete";
+    summary = `The bot_ci check is currently ${botCiCheck.status}. Merging is blocked until it completes successfully.`;
+  } else if (botCiCheck.conclusion === "success") {
+    status = "completed";
+    conclusion = "success";
+    title = "bot_ci passed";
+    summary = "The bot_ci check has passed. Merging is allowed.";
+  } else {
+    status = "completed";
+    conclusion = "failure";
+    title = `bot_ci ${botCiCheck.conclusion || "failed"}`;
+    summary = `The bot_ci check has ${botCiCheck.conclusion || "failed"}. Merging is blocked.`;
+  }
+
+  if (existingChecks.data.check_runs.length > 0) {
+    const existingCheck = existingChecks.data.check_runs[0];
+    await context.octokit.checks.update({
+      owner,
+      repo,
+      check_run_id: existingCheck.id,
+      status,
+      conclusion,
+      output: {
+        title,
+        summary,
+      },
+    });
+  } else {
+    await context.octokit.checks.create({
+      owner,
+      repo,
+      name: MERGEABLE_CHECK_NAME,
+      head_sha: headSha,
+      status,
+      conclusion,
+      output: {
+        title,
+        summary,
+      },
+    });
+  }
+}
+
+async function handleBotCiCheck(
+  context: ProbotContext,
+  owner: string,
+  repo: string,
+  headSha: string,
+): Promise<void> {
+  const botCiCheck = await getBotCiCheckRun(context, owner, repo, headSha);
+  await createOrUpdateMergeableCheck(context, owner, repo, headSha, botCiCheck);
+}
+
+export function registerMergeableHandlers(app: Probot): void {
+  app.on(
+    ["check_run.created", "check_run.completed", "check_run.rerequested"],
+    async (context) => {
+      const checkRun = context.payload.check_run;
+
+      if (checkRun.name !== BOT_CI_CHECK_NAME) {
+        return;
+      }
+
+      const pullRequests = checkRun.pull_requests;
+      if (pullRequests.length === 0) {
+        context.log.info("No pull requests associated with this check run");
+        return;
+      }
+
+      const owner = context.payload.repository.owner.login;
+      const repo = context.payload.repository.name;
+      const headSha = checkRun.head_sha;
+
+      context.log.info(
+        `bot_ci check ${context.payload.action} for ${owner}/${repo}@${headSha}`,
+      );
+
+      try {
+        await handleBotCiCheck(context, owner, repo, headSha);
+      } catch (error) {
+        context.log.error(`Failed to handle bot_ci check: ${error}`);
+      }
+    },
+  );
+
+  app.on(
+    [
+      "pull_request.opened",
+      "pull_request.synchronize",
+      "pull_request.reopened",
+    ],
+    async (context) => {
+      const pr = context.payload.pull_request;
+      const owner = context.payload.repository.owner.login;
+      const repo = context.payload.repository.name;
+      const headSha = pr.head.sha;
+
+      context.log.info(
+        `PR ${context.payload.action} for ${owner}/${repo}#${pr.number}`,
+      );
+
+      try {
+        await handleBotCiCheck(context, owner, repo, headSha);
+      } catch (error) {
+        context.log.error(`Failed to handle PR event: ${error}`);
+      }
+    },
+  );
+}

apps/bot/test/fixtures/check_run.completed.failure.json

@@ -0,0 +1,27 @@
+{
+  "action": "completed",
+  "check_run": {
+    "id": 1,
+    "name": "bot_ci",
+    "head_sha": "abc123",
+    "status": "completed",
+    "conclusion": "failure",
+    "pull_requests": [
+      {
+        "number": 123
+      }
+    ]
+  },
+  "repository": {
+    "id": 1,
+    "node_id": "MDEwOlJlcG9zaXRvcnkx",
+    "name": "testing-things",
+    "full_name": "hiimbex/testing-things",
+    "owner": {
+      "login": "hiimbex"
+    }
+  },
+  "installation": {
+    "id": 2
+  }
+}

apps/bot/test/fixtures/check_run.completed.success.json

@@ -0,0 +1,27 @@
+{
+  "action": "completed",
+  "check_run": {
+    "id": 1,
+    "name": "bot_ci",
+    "head_sha": "abc123",
+    "status": "completed",
+    "conclusion": "success",
+    "pull_requests": [
+      {
+        "number": 123
+      }
+    ]
+  },
+  "repository": {
+    "id": 1,
+    "node_id": "MDEwOlJlcG9zaXRvcnkx",
+    "name": "testing-things",
+    "full_name": "hiimbex/testing-things",
+    "owner": {
+      "login": "hiimbex"
+    }
+  },
+  "installation": {
+    "id": 2
+  }
+}

apps/bot/test/fixtures/check_run.created.json

@@ -0,0 +1,27 @@
+{
+  "action": "created",
+  "check_run": {
+    "id": 1,
+    "name": "bot_ci",
+    "head_sha": "abc123",
+    "status": "in_progress",
+    "conclusion": null,
+    "pull_requests": [
+      {
+        "number": 123
+      }
+    ]
+  },
+  "repository": {
+    "id": 1,
+    "node_id": "MDEwOlJlcG9zaXRvcnkx",
+    "name": "testing-things",
+    "full_name": "hiimbex/testing-things",
+    "owner": {
+      "login": "hiimbex"
+    }
+  },
+  "installation": {
+    "id": 2
+  }
+}

apps/bot/test/fixtures/pull_request.opened.json

@@ -0,0 +1,24 @@
+{
+  "action": "opened",
+  "number": 123,
+  "pull_request": {
+    "number": 123,
+    "html_url": "https://github.com/example/repo/pull/123",
+    "created_at": "2024-01-01T00:00:00Z",
+    "head": {
+      "sha": "abc123"
+    }
+  },
+  "repository": {
+    "id": 1,
+    "node_id": "MDEwOlJlcG9zaXRvcnkx",
+    "name": "testing-things",
+    "full_name": "hiimbex/testing-things",
+    "owner": {
+      "login": "hiimbex"
+    }
+  },
+  "installation": {
+    "id": 2
+  }
+}