chore(readme): add dynamic coverage badge

.github/workflows/ci.yml

@@ -44,6 +44,18 @@ jobs:
       - name: Collect coverage
         run: yarn test:coverage
 
+      - name: Write coverage badge payload
+        if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+        run: node scripts/write-coverage-badge.mjs
+
+      - name: Upload coverage badge
+        if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+        uses: actions/upload-artifact@v4
+        with:
+          name: coverage-badge
+          path: badges/coverage.json
+          if-no-files-found: error
+
       - name: Lint
         run: yarn lint
 
@@ -84,6 +96,32 @@ jobs:
           path: coverage/coverage-summary.json
           if-no-files-found: warn
 
+  publish-coverage-badge:
+    name: Publish Coverage Badge
+    runs-on: ubuntu-22.04
+    needs: quality
+    if: github.event_name == 'push' && github.ref == 'refs/heads/master'
+    permissions:
+      contents: write
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          ref: ${{ github.ref_name }}
+
+      - name: Download coverage badge
+        uses: actions/download-artifact@v4
+        with:
+          name: coverage-badge
+          path: badges/
+
+      - run: git add badges/coverage.json
+      - run: git status
+      - uses: stefanzweifel/git-auto-commit-action@v4
+        with:
+          commit_message: 'chore(ci): update coverage badge'
+          file_pattern: 'badges/coverage.json'
+          branch: ${{ github.ref_name }}
+
   android-build:
     name: Android Build
     runs-on: ubuntu-22.04

README.md

@@ -1,4 +1,5 @@
 [![Build Status](https://img.shields.io/github/actions/workflow/status/bitsocialnet/5chan/ci.yml?branch=master)](https://github.com/bitsocialnet/5chan/actions/workflows/ci.yml)
+[![Coverage](https://img.shields.io/endpoint?url=https://raw.githubusercontent.com/bitsocialnet/5chan/master/badges/coverage.json)](https://github.com/bitsocialnet/5chan/actions/workflows/ci.yml)
 [![Release](https://img.shields.io/github/v/release/bitsocialnet/5chan)](https://github.com/bitsocialnet/5chan/releases/latest)
 [![License](https://img.shields.io/badge/license-GPL--2.0--only-red.svg)](https://github.com/bitsocialnet/5chan/blob/master/LICENSE)
 [![Commitizen friendly](https://img.shields.io/badge/commitizen-friendly-brightgreen.svg)](http://commitizen.github.io/cz-cli/)

badges/coverage.json

@@ -0,0 +1,6 @@
+{
+  "schemaVersion": 1,
+  "label": "coverage",
+  "message": "pending",
+  "color": "lightgrey"
+}

scripts/write-coverage-badge.mjs

@@ -0,0 +1,51 @@
+import fs from "fs";
+import path from "path";
+
+const CWD = process.cwd();
+const COVERAGE_SUMMARY_PATHS = [
+  path.join(CWD, "coverage", "coverage-summary.json"),
+  path.join(CWD, "src", "coverage", "coverage-summary.json"),
+];
+const BADGE_OUTPUT_PATH = path.join(CWD, "badges", "coverage.json");
+
+const coverageSummaryPath = COVERAGE_SUMMARY_PATHS.find((candidate) => fs.existsSync(candidate));
+if (!coverageSummaryPath) {
+  const checkedPaths = COVERAGE_SUMMARY_PATHS.map((candidate) => `"${candidate}"`).join(", ");
+  console.error(`[coverage-badge] Missing coverage summary. Checked: ${checkedPaths}.`);
+  process.exit(1);
+}
+
+const summary = JSON.parse(fs.readFileSync(coverageSummaryPath, "utf8"));
+const lineCoveragePct = summary?.total?.lines?.pct;
+if (typeof lineCoveragePct !== "number") {
+  console.error(`[coverage-badge] Missing total.lines.pct in "${coverageSummaryPath}".`);
+  process.exit(1);
+}
+
+const roundedPct = Number(lineCoveragePct.toFixed(1));
+const color =
+  lineCoveragePct >= 95
+    ? "brightgreen"
+    : lineCoveragePct >= 90
+      ? "green"
+      : lineCoveragePct >= 80
+        ? "yellowgreen"
+        : lineCoveragePct >= 70
+          ? "yellow"
+          : lineCoveragePct >= 60
+            ? "orange"
+            : "red";
+
+const badge = {
+  schemaVersion: 1,
+  label: "coverage",
+  message: `${roundedPct}%`,
+  color,
+};
+
+fs.mkdirSync(path.dirname(BADGE_OUTPUT_PATH), { recursive: true });
+fs.writeFileSync(BADGE_OUTPUT_PATH, `${JSON.stringify(badge, null, 2)}\n`);
+
+console.log(
+  `[coverage-badge] Wrote "${BADGE_OUTPUT_PATH}" from "${coverageSummaryPath}" (${roundedPct}%).`,
+);