From a6c0bc9db1e265484c275860fdb41fcfd8aefaf2 Mon Sep 17 00:00:00 2001
From: Francesco Trotta <github@fasttime.org>
Date: Thu, 21 Nov 2024 17:42:45 +0100
Subject: [PATCH] fix: add type tests (#65)

---
 .github/workflows/ci.yml       | 15 +++++++++++++++
 package.json                   |  3 ++-
 src/index.js                   |  4 ++--
 src/rules/no-duplicate-keys.js |  2 +-
 src/rules/no-empty-keys.js     |  2 +-
 src/rules/no-unsafe-values.js  |  2 +-
 tests/types/tsconfig.json      |  9 +++++++++
 tests/types/types.test.ts      | 23 +++++++++++++++++++++++
 8 files changed, 54 insertions(+), 6 deletions(-)
 create mode 100644 tests/types/tsconfig.json
 create mode 100644 tests/types/types.test.ts

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 06a2216..974282e 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -45,6 +45,21 @@ jobs:
               run: npm install
             - name: Run tests
               run: npm run test
+    test_types:
+        name: Test Types
+        runs-on: ubuntu-latest
+        steps:
+            - uses: actions/checkout@v4
+            - name: Setup Node.js
+              uses: actions/setup-node@v4
+              with:
+                  node-version: "lts/*"
+            - name: Install dependencies
+              run: npm install
+            - name: Build
+              run: npm run build
+            - name: Check Types
+              run: npm run test:types
     jsr_test:
         name: Verify JSR Publish
         runs-on: ubuntu-latest
diff --git a/package.json b/package.json
index f2d9406..d6f030b 100644
--- a/package.json
+++ b/package.json
@@ -51,7 +51,8 @@
     "fmt": "prettier --write .",
     "fmt:check": "prettier --check .",
     "test": "mocha tests/**/*.js",
-    "test:coverage": "c8 npm test"
+    "test:coverage": "c8 npm test",
+    "test:types": "tsc -p tests/types/tsconfig.json"
   },
   "keywords": [
     "eslint",
diff --git a/src/index.js b/src/index.js
index bcc04ca..6181006 100644
--- a/src/index.js
+++ b/src/index.js
@@ -35,11 +35,11 @@ const plugin = {
 	configs: {
 		recommended: {
 			plugins: {},
-			rules: {
+			rules: /** @type {const} */ ({
 				"json/no-duplicate-keys": "error",
 				"json/no-empty-keys": "error",
 				"json/no-unsafe-values": "error",
-			},
+			}),
 		},
 	},
 };
diff --git a/src/rules/no-duplicate-keys.js b/src/rules/no-duplicate-keys.js
index 345425d..3499526 100644
--- a/src/rules/no-duplicate-keys.js
+++ b/src/rules/no-duplicate-keys.js
@@ -9,7 +9,7 @@
 
 export default {
 	meta: {
-		type: "problem",
+		type: /** @type {const} */ ("problem"),
 
 		docs: {
 			description: "Disallow duplicate keys in JSON objects",
diff --git a/src/rules/no-empty-keys.js b/src/rules/no-empty-keys.js
index c86e25a..3fedc4f 100644
--- a/src/rules/no-empty-keys.js
+++ b/src/rules/no-empty-keys.js
@@ -5,7 +5,7 @@
 
 export default {
 	meta: {
-		type: "problem",
+		type: /** @type {const} */ ("problem"),
 
 		docs: {
 			description: "Disallow empty keys in JSON objects",
diff --git a/src/rules/no-unsafe-values.js b/src/rules/no-unsafe-values.js
index 85a21f5..f341729 100644
--- a/src/rules/no-unsafe-values.js
+++ b/src/rules/no-unsafe-values.js
@@ -5,7 +5,7 @@
 
 export default {
 	meta: {
-		type: "problem",
+		type: /** @type {const} */ ("problem"),
 
 		docs: {
 			description: "Disallow JSON values that are unsafe for interchange",
diff --git a/tests/types/tsconfig.json b/tests/types/tsconfig.json
new file mode 100644
index 0000000..6bf4343
--- /dev/null
+++ b/tests/types/tsconfig.json
@@ -0,0 +1,9 @@
+{
+  "extends": "../../tsconfig.json",
+  "compilerOptions": {
+    "noEmit": true,
+    "rootDir": "../..",
+    "strict": true
+  },
+  "files": ["../../dist/esm/index.d.ts", "types.test.ts"]
+}
diff --git a/tests/types/types.test.ts b/tests/types/types.test.ts
new file mode 100644
index 0000000..a9f5374
--- /dev/null
+++ b/tests/types/types.test.ts
@@ -0,0 +1,23 @@
+import json from "@eslint/json";
+import { ESLint } from "eslint";
+
+json satisfies ESLint.Plugin;
+json.meta.name satisfies string;
+json.meta.version satisfies string;
+
+// Check that these languages are defined:
+json.languages.json satisfies object;
+json.languages.json5 satisfies object;
+json.languages.jsonc satisfies object;
+
+// Check that `plugins` in the recommended config is defined:
+json.configs.recommended.plugins satisfies object;
+
+{
+	type RecommendedRuleName = keyof typeof json.configs.recommended.rules;
+	type RuleName = `json/${keyof typeof json.rules}`;
+	type AssertAllNamesIn<T1 extends T2, T2> = never;
+
+	// Check that all recommended rule names match the names of existing rules in this plugin.
+	null as AssertAllNamesIn<RecommendedRuleName, RuleName>;
+}