CI: add a merge script

.github/workflows/auto-merge.yml

@@ -0,0 +1,28 @@
+name: auto-merge
+
+on:
+  issue_comment:
+  schedule:
+    - cron: '14 12 * * *'
+  workflow_dispatch: {}
+
+jobs:
+  merge:
+    runs-on: ubuntu-latest
+    if: ${{ (github.event.issue && github.event.issue.pull_request) || !github.event.issue }}
+    steps:
+      - uses: actions/checkout@v3
+        with:
+          fetch-depth: 0
+          submodules: true
+      - run: npm install execa@5
+      - uses: actions/github-script@v5
+        name: Check and Merge
+        id: check-changes
+        with:
+          script: |
+            const execa = require("execa");
+            const mergebot = require('./.github/workflows/merge.js');
+            const branch = await mergebot.checkChanges(github);
+            if (branch)
+              await mergeChanges(branch, execa);

.github/workflows/merge.js

@@ -0,0 +1,97 @@
+// Note: This is a GitHub Actions script
+// It is not meant to be executed directly on your machine without modifications
+
+const fs = require("fs");
+
+const check_query = `query($name: String!){
+  repository(name: $name, owner: "flathub") {
+    pullRequests(states: OPEN, first: 50, baseRefName: "master", orderBy: {field: CREATED_AT, direction: DESC}) {
+      nodes {
+        id number headRefName mergeable
+        author { login }
+      }
+    }
+  }
+}`;
+
+const close_pr_mutation = `mutation cpm_{num} {
+  closePullRequest(input: {pullRequestId: "{id}"})
+}`;
+
+async function closePullRequests(should_close, github) {
+  if (should_close.length > 0) {
+    console.log("Closing other pull requests ...");
+    let mut = "";
+    for (let i = 0; i < should_close.length; i++) {
+      mut += close_pr_mutation.replace("{num}", i).replace(
+        "{id}",
+        should_close[i].id,
+      );
+      mut += "\n";
+    }
+    await github.graphql(mut);
+    console.log("Pull requests closed.");
+  }
+}
+
+async function incrementVersion() {
+  const manifest = fs.readFileSync("org.yuzu_emu.yuzu.json");
+  const version = /mainline-0-(\d+)/.exec(manifest)[1];
+  const new_manifest = manifest.replace(
+    /-DDISPLAY_VERSION=\d+/,
+    `-DDISPLAY_VERSION=${version}`,
+  ).replace(/-DBUILD_TAG=mainline-\d+/, `-DBUILD_TAG=mainline-${version}`);
+  fs.writeFileSync("org.yuzu_emu.yuzu.json", new_manifest);
+}
+
+async function mergeChanges(branch, execa) {
+  let mergeResults = {};
+  try {
+    const process = await execa("git", [
+      "merge",
+      "--ff-only",
+      `origin/${branch}`,
+    ]);
+    process.stdout.pipe(process.stdout);
+    await incrementVersion();
+    await execa("git", [
+      "add",
+      "org.yuzu_emu.yuzu.json"
+    ]);
+    const process1 = await execa("git", ["commit", "--amend"]);
+    process1.stdout.pipe(process.stdout);
+  } catch (err) {
+    console.log(
+      `::error title=Merge failed::Failed to merge pull request: ${err}`,
+    );
+  }
+
+  const process = await execa("git", ["push", "origin", `master:${branch}`, "-f"]);
+  process.stdout.pipe(process.stdout);
+  await new Promise(r => setTimeout(r, 2000));
+  const process1 = await execa("git", ["push", "origin"]);
+  process1.stdout.pipe(process1.stdout);
+}
+
+async function checkChanges(github, context) {
+  const variables = {
+    name: context.repo.repo,
+  };
+  const result = await github.graphql(check_query, variables);
+  const prs = result.repository.pullRequests.nodes;
+  const auto_prs = prs.filter(
+    (pr) => pr.author.login === "flathubbot" && pr.mergeable === "MERGEABLE",
+  );
+  if (auto_prs.length < 1) {
+    console.warn("No pull requests available for merge.");
+    return null;
+  }
+  const chosen = auto_prs[0];
+  const should_close = auto_prs.slice(1);
+  console.log(`Selected pull request: #${chosen.num}`);
+  await closePullRequests(should_close, github);
+  return chosen.headRefName;
+}
+
+module.exports.checkChanges = checkChanges;
+module.exports.mergeChanges = mergeChanges;