chore: set up tests with mocha

.github/workflows/code_health.yaml

@@ -19,3 +19,17 @@ jobs:
               run: npm ci
             - name: Run style check
               run: npm run check
+
+    run-tests:
+        runs-on: ubuntu-latest
+        steps:
+            - uses: GitHubSecurityLab/actions-permissions/monitor@v1
+            - uses: actions/checkout@v4
+            - uses: actions/setup-node@v4
+              with:
+                  node-version-file: package.json
+                  cache: "npm"
+            - name: Install dependencies
+              run: npm ci
+            - name: Run tests
+              run: npm test

eslint.config.js

@@ -3,11 +3,17 @@ import js from "@eslint/js";
 import globals from "globals";
 import tseslint from "typescript-eslint";
 import eslintConfigPrettier from "eslint-config-prettier/flat";
+import mochaPlugin from "eslint-plugin-mocha";
 
 export default defineConfig([
     { files: ["src/**/*.ts"], plugins: { js }, extends: ["js/recommended"] },
     { files: ["src/**/*.ts"], languageOptions: { globals: globals.node } },
+    {
+        files: ["**/*.spec.ts"],
+        env: { mocha: true },
+    },
     tseslint.configs.recommended,
     eslintConfigPrettier,
     globalIgnores(["node_modules", "dist"]),
+    mochaPlugin.configs.flat.recommended,
 ]);