Set up strict linting

.github/workflows/ci.yml

@@ -3,6 +3,8 @@ name: CI
 on:
   pull_request:
   push:
+    branches:
+      - main
 
 permissions: {}
 
@@ -32,5 +34,9 @@ jobs:
         run: pnpm run format:check
       - name: Build
         run: pnpm run build
+      - name: Lint
+        run: pnpm run lint
+      - name: Knip
+        run: pnpm run knip
       - name: Integration test
         run: pnpm run test:integration

eslint.config.js

@@ -0,0 +1,64 @@
+import js from "@eslint/js";
+import tseslint from "typescript-eslint";
+
+export default [
+  {
+    ignores: ["dist/**"],
+  },
+  js.configs.recommended,
+  {
+    files: ["**/*.{js,mjs,cjs,ts}"],
+    rules: {
+      curly: ["error", "all"],
+      "no-restricted-syntax": [
+        "error",
+        {
+          selector: "CallExpression[callee.name='Boolean']",
+          message:
+            "Avoid truthiness coercion. Use an explicit condition or comparison instead.",
+        },
+        {
+          selector:
+            "UnaryExpression[operator='!'] > BinaryExpression[operator='!=']",
+          message:
+            "Avoid negating comparisons. Use the inverse operator directly.",
+        },
+        {
+          selector:
+            "UnaryExpression[operator='!'] > BinaryExpression[operator='!==']",
+          message:
+            "Avoid negating comparisons. Use the inverse operator directly.",
+        },
+      ],
+    },
+  },
+  ...[
+    ...tseslint.configs.strictTypeChecked,
+    ...tseslint.configs.stylisticTypeChecked,
+  ].map((config) => ({
+    ...config,
+    files: ["**/*.ts"],
+  })),
+  {
+    files: ["**/*.ts"],
+    languageOptions: {
+      parserOptions: {
+        project: "./tsconfig.eslint.json",
+        tsconfigRootDir: import.meta.dirname,
+      },
+    },
+    rules: {
+      "@typescript-eslint/consistent-type-assertions": [
+        "error",
+        {
+          assertionStyle: "never",
+        },
+      ],
+      "@typescript-eslint/consistent-type-definitions": ["error", "type"],
+      "@typescript-eslint/prefer-readonly": "error",
+      "@typescript-eslint/strict-boolean-expressions": "error",
+      "@typescript-eslint/strict-void-return": "error",
+      "@typescript-eslint/switch-exhaustiveness-check": "error",
+    },
+  },
+];

package.json

@@ -40,22 +40,28 @@
     "build": "tsdown && tsc --emitDeclarationOnly",
     "format": "prettier --write .",
     "format:check": "prettier --check .",
+    "knip": "knip --strict --treat-config-hints-as-errors --treat-tag-hints-as-errors",
+    "lint": "eslint .",
     "test:integration": "pnpm run build && tsc --noEmit -p tsconfig.test.json && vitest run test/integration"
   },
   "dependencies": {
+    "@langfuse/otel": "^5.10.1",
     "@opencode-ai/plugin": "^1.15.13",
-    "@opentelemetry/api": "^1.9.1"
+    "@opentelemetry/api": "^1.9.1",
+    "@opentelemetry/resources": "^2.10.0",
+    "@opentelemetry/sdk-trace-base": "^2.10.0",
+    "@opentelemetry/sdk-trace-node": "^2.10.0",
+    "effect": "^3.22.1"
   },
   "devDependencies": {
-    "@langfuse/otel": "^5.4.1",
-    "@opentelemetry/resources": "^2.7.1",
-    "@opentelemetry/sdk-trace-base": "^2.7.1",
-    "@opentelemetry/sdk-trace-node": "^2.7.1",
+    "@eslint/js": "^10.0.1",
     "@types/node": "^26.1.2",
-    "effect": "^3.21.2",
+    "eslint": "^10.8.1",
+    "knip": "^6.32.2",
     "prettier": "^3.8.3",
     "tsdown": "0.22.14",
     "typescript": "^6.0.3",
+    "typescript-eslint": "^8.67.0",
     "vitest": "4.1.6"
   }
 }