feat: support for nested objects in frontmatter

.github/workflows/test.yml

@@ -0,0 +1,21 @@
+name: test
+
+on:
+  pull_request:
+  push:
+    branches: [main]
+
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v4
+
+      - uses: actions/setup-node@v4
+        with:
+          node-version: 20
+          cache: npm
+
+      - run: npm ci
+
+      - run: npx jest --ci

jest.config.js

@@ -0,0 +1,21 @@
+/** @type {import('jest').Config} */
+module.exports = {
+  preset: "ts-jest",
+  testEnvironment: "node",
+  rootDir: ".",
+  roots: ["<rootDir>/src"],
+  testMatch: ["**/__tests__/**/*.test.ts"],
+  // tsconfig.json sets baseUrl to "src" — mirror that here so the same
+  // src-relative imports work in tests.
+  moduleDirectories: ["node_modules", "src"],
+  moduleFileExtensions: ["ts", "tsx", "js"],
+  transform: {
+    "^.+\\.tsx?$": [
+      "ts-jest",
+      {
+        tsconfig: { jsx: "react", esModuleInterop: true, target: "es2018" },
+        diagnostics: false,
+      },
+    ],
+  },
+};