feat: add unicorn/consistent-existence-index-check

BREAKING CHANGE: New rule introduced

.github/workflows/lint.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: "actions/checkout@v4.2.2"
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.1.0"
+        uses: "actions/setup-node@v4.2.0"
         with:
           node-version: "lts/*"
           cache: "npm"

.github/workflows/release.yml

@@ -19,7 +19,7 @@ jobs:
           persist-credentials: false
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.1.0"
+        uses: "actions/setup-node@v4.2.0"
         with:
           node-version: "lts/*"
           cache: "npm"

.github/workflows/test.yml

@@ -13,7 +13,7 @@ jobs:
       - uses: "actions/checkout@v4.2.2"
 
       - name: "Setup Node.js"
-        uses: "actions/setup-node@v4.1.0"
+        uses: "actions/setup-node@v4.2.0"
         with:
           node-version: "lts/*"
           cache: "npm"

README.md

@@ -35,13 +35,13 @@ More information about **formatting rules** vs **code-quality rules** can be fou
 
 ```sh
 npm install --save-dev \
-  eslint@^9.12.0 \
+  eslint@^9.21.0 \
-  eslint-plugin-promise@^7.1.0 \
+  eslint-plugin-promise@^7.2.1 \
-  eslint-plugin-unicorn@^56.0.0 \
+  eslint-plugin-unicorn@^57.0.0 \
-  eslint-plugin-import-x@^4.3.1 \
+  eslint-plugin-import-x@^4.6.1 \
-  globals@^15.10.0 \
+  globals@^16.0.0 \
-  typescript@~5.5.4 \
+  typescript@^5.7.3 \
-  typescript-eslint@^8.8.0 \
+  typescript-eslint@^8.24.1 \
   eslint-config-conventions@latest
 ```
 

eslint.config.js

@@ -79,7 +79,13 @@ export default typescriptESLint.config(
       "no-unused-vars": [
         "error",
         {
+          args: "all",
+          argsIgnorePattern: "^_",
+          caughtErrors: "all",
+          caughtErrorsIgnorePattern: "^_",
+          destructuredArrayIgnorePattern: "^_",
           varsIgnorePattern: "^_",
+          ignoreRestSiblings: true,
         },
       ],
       "no-use-before-define": [
@@ -126,6 +132,8 @@ export default typescriptESLint.config(
       "no-array-constructor": "error",
       "no-caller": "error",
       "no-delete-var": "error",
+      "no-implicit-coercion": "error",
+      "no-extra-boolean-cast": ["error", { enforceForInnerExpressions: true }],
       "no-empty": [
         "error",
         {
@@ -217,6 +225,7 @@ export default typescriptESLint.config(
       "unicorn/better-regex": "error",
       "unicorn/catch-error-name": "error",
       "unicorn/custom-error-definition": "error",
+      "unicorn/consistent-date-clone": "error",
       "unicorn/error-message": "error",
       "unicorn/escape-case": "error",
       "unicorn/explicit-length-check": "error",
@@ -225,9 +234,10 @@ export default typescriptESLint.config(
       "unicorn/no-array-for-each": "error",
       "unicorn/no-array-method-this-argument": "error",
       "unicorn/no-document-cookie": "error",
+      "unicorn/no-named-default": "error",
       "unicorn/no-empty-file": "error",
       "unicorn/no-hex-escape": "error",
-      "unicorn/no-instanceof-array": "error",
+      "unicorn/no-instanceof-builtins": "error",
       "unicorn/no-new-array": "error",
       "unicorn/no-new-buffer": "error",
       "unicorn/no-this-assignment": "error",
@@ -241,6 +251,7 @@ export default typescriptESLint.config(
       "unicorn/prefer-modern-math-apis": "error",
       "unicorn/prefer-structured-clone": "error",
       "unicorn/template-indent": "error",
+      "unicorn/consistent-existence-index-check": "error",
 
       "import-x/no-absolute-path": "error",
       "import-x/no-webpack-loader-syntax": "error",
@@ -272,19 +283,25 @@ export default typescriptESLint.config(
 
     rules: {
       "no-undef": "off",
+
       "no-dupe-class-members": "off",
       "@typescript-eslint/no-dupe-class-members": "error",
-      "no-unused-vars": "off",
 
+      "no-unused-vars": "off",
       "@typescript-eslint/no-unused-vars": [
         "error",
         {
+          args: "all",
+          argsIgnorePattern: "^_",
+          caughtErrors: "all",
+          caughtErrorsIgnorePattern: "^_",
+          destructuredArrayIgnorePattern: "^_",
           varsIgnorePattern: "^_",
+          ignoreRestSiblings: true,
         },
       ],
 
       "no-use-before-define": "off",
-
       "@typescript-eslint/no-use-before-define": [
         "error",
         {
@@ -298,12 +315,14 @@ export default typescriptESLint.config(
 
       "default-param-last": "off",
       "@typescript-eslint/default-param-last": "error",
+
       "no-array-constructor": "off",
       "@typescript-eslint/no-array-constructor": "error",
+
       "no-implied-eval": "off",
       "@typescript-eslint/no-implied-eval": "error",
-      "no-redeclare": "off",
 
+      "no-redeclare": "off",
       "@typescript-eslint/no-redeclare": [
         "error",
         {
@@ -313,8 +332,8 @@ export default typescriptESLint.config(
 
       "no-throw-literal": "off",
       "@typescript-eslint/only-throw-error": "error",
-      "no-unused-expressions": "off",
 
+      "no-unused-expressions": "off",
       "@typescript-eslint/no-unused-expressions": [
         "error",
         {
@@ -326,23 +345,18 @@ export default typescriptESLint.config(
 
       "no-useless-constructor": "off",
       "@typescript-eslint/no-useless-constructor": "error",
+
       "@typescript-eslint/no-unnecessary-template-expression": "error",
-
       "@typescript-eslint/adjacent-overload-signatures": "error",
 
-      "@typescript-eslint/array-type": [
-        "error",
-        {
-          default: "array-simple",
-        },
-      ],
-
       "@typescript-eslint/no-unsafe-function-type": "error",
       "@typescript-eslint/no-wrapper-object-types": "error",
       "@typescript-eslint/consistent-type-definitions": ["error", "interface"],
+
       "no-duplicate-imports": "off",
       "@typescript-eslint/consistent-type-imports": "error",
 
+      "@typescript-eslint/explicit-member-accessibility": "error",
       "@typescript-eslint/explicit-function-return-type": [
         "error",
         {
@@ -354,7 +368,6 @@ export default typescriptESLint.config(
       ],
 
       "@typescript-eslint/method-signature-style": "error",
-      "@typescript-eslint/unbound-method": "error",
 
       "@typescript-eslint/naming-convention": [
         "error",
@@ -379,7 +392,19 @@ export default typescriptESLint.config(
         },
       ],
 
-      "@typescript-eslint/no-floating-promises": "error",
+      "@typescript-eslint/no-floating-promises": [
+        "error",
+        {
+          allowForKnownSafeCalls: [
+            {
+              from: "package",
+              name: ["it", "describe"],
+              package: "node:test",
+            },
+          ],
+        },
+      ],
+
       "@typescript-eslint/no-for-in-array": "error",
       "@typescript-eslint/no-invalid-void-type": "error",
       "@typescript-eslint/no-misused-new": "error",
@@ -417,6 +442,7 @@ export default typescriptESLint.config(
       "@typescript-eslint/prefer-reduce-type-parameter": "error",
       "@typescript-eslint/prefer-return-this-type": "error",
       "@typescript-eslint/promise-function-async": "error",
+
       "prefer-promise-reject-errors": "off",
       "@typescript-eslint/prefer-promise-reject-errors": "error",
 

package.json

@@ -45,25 +45,24 @@
     "release": "semantic-release"
   },
   "peerDependencies": {
-    "eslint": "^9.12.0",
+    "eslint": "^9.21.0",
-    "eslint-plugin-promise": "^7.1.0",
+    "eslint-plugin-promise": "^7.2.1",
-    "eslint-plugin-unicorn": "^56.0.0",
+    "eslint-plugin-unicorn": "^57.0.0",
-    "eslint-plugin-import-x": "^4.3.1",
+    "eslint-plugin-import-x": "^4.6.1",
-    "globals": "^15.10.0",
+    "globals": "^16.0.0",
-    "typescript-eslint": "^8.8.0"
+    "typescript-eslint": "^8.24.1"
   },
   "devDependencies": {
-    "@types/eslint__js": "8.42.3",
+    "@types/node": "22.13.5",
-    "@types/node": "22.9.0",
+    "globals": "16.0.0",
-    "globals": "15.12.0",
+    "editorconfig-checker": "6.0.1",
-    "editorconfig-checker": "6.0.0",
+    "eslint": "9.21.0",
-    "eslint": "9.14.0",
+    "eslint-plugin-promise": "7.2.1",
-    "eslint-plugin-promise": "7.1.0",
+    "eslint-plugin-unicorn": "57.0.0",
-    "eslint-plugin-unicorn": "56.0.0",
+    "eslint-plugin-import-x": "4.6.1",
-    "eslint-plugin-import-x": "4.4.0",
+    "typescript-eslint": "8.24.1",
-    "typescript-eslint": "8.14.0",
+    "prettier": "3.5.2",
-    "prettier": "3.3.3",
+    "semantic-release": "24.2.3",
-    "semantic-release": "23.1.1",
+    "typescript": "5.7.3"
-    "typescript": "5.6.3"
   }
 }

test/validate-config.js

@@ -1,77 +0,0 @@
-import test from "node:test"
-import assert from "node:assert/strict"
-
-import { ESLint } from "eslint"
-
-const eslint = new ESLint()
-
-test("ensure we validate correctly JavaScript files", async () => {
-  const [noErrors] = await eslint.lintFiles(
-    "test/fixtures/javascript-no-errors.js",
-  )
-  const [withErrors] = await eslint.lintFiles(
-    "test/fixtures/javascript-with-errors.js",
-  )
-  assert.strictEqual(noErrors?.errorCount, 0, JSON.stringify(noErrors, null, 2))
-  assert.strictEqual(
-    withErrors?.errorCount,
-    3,
-    JSON.stringify(withErrors, null, 2),
-  )
-})
-
-test("ensure we do not use deprecated rules", async () => {
-  const [javascriptLintResult] = await eslint.lintFiles(
-    "test/fixtures/javascript-no-errors.js",
-  )
-  const [typescriptLintResult] = await eslint.lintFiles(
-    "test/fixtures/typescript-no-errors.ts",
-  )
-  assert.strictEqual(
-    javascriptLintResult.usedDeprecatedRules.length,
-    0,
-    JSON.stringify(javascriptLintResult, null, 2),
-  )
-  assert.strictEqual(
-    typescriptLintResult.usedDeprecatedRules.length,
-    0,
-    JSON.stringify(typescriptLintResult, null, 2),
-  )
-})
-
-test("ensure we validate correctly TypeScript files", async () => {
-  const [noErrors] = await eslint.lintFiles(
-    "test/fixtures/typescript-no-errors.ts",
-  )
-  const [withErrors] = await eslint.lintFiles(
-    "test/fixtures/javascript-with-errors.js",
-  )
-  assert.strictEqual(noErrors?.errorCount, 0, JSON.stringify(noErrors, null, 2))
-  assert.strictEqual(
-    withErrors?.errorCount,
-    3,
-    JSON.stringify(withErrors, null, 2),
-  )
-})
-
-test("ensure we allow top-level await", async () => {
-  const [lintResult] = await eslint.lintFiles(
-    "test/fixtures/top-level-await.mjs",
-  )
-  assert.strictEqual(
-    lintResult?.errorCount,
-    0,
-    JSON.stringify(lintResult, null, 2),
-  )
-})
-
-test("ensure we allow to ignore floating promise with void operator (@typescript-eslint/no-floating-promises)", async () => {
-  const [lintResult] = await eslint.lintFiles(
-    "test/fixtures/typescript-no-errors-ignore-promise.ts",
-  )
-  assert.strictEqual(
-    lintResult?.errorCount,
-    0,
-    JSON.stringify(lintResult, null, 2),
-  )
-})

test/validate-config.test.js

@@ -0,0 +1,87 @@
+import assert from "node:assert/strict"
+import { describe, it } from "node:test"
+
+import { ESLint } from "eslint"
+
+const eslint = new ESLint()
+
+describe("ESLint configuration", () => {
+  it("should validate correctly JavaScript files", async () => {
+    const [noErrors] = await eslint.lintFiles(
+      "test/fixtures/javascript-no-errors.js",
+    )
+    const [withErrors] = await eslint.lintFiles(
+      "test/fixtures/javascript-with-errors.js",
+    )
+    assert.strictEqual(
+      noErrors?.errorCount,
+      0,
+      JSON.stringify(noErrors, null, 2),
+    )
+    assert.strictEqual(
+      withErrors?.errorCount,
+      3,
+      JSON.stringify(withErrors, null, 2),
+    )
+  })
+
+  it("should validate correctly TypeScript files", async () => {
+    const [noErrors] = await eslint.lintFiles(
+      "test/fixtures/typescript-no-errors.ts",
+    )
+    const [withErrors] = await eslint.lintFiles(
+      "test/fixtures/javascript-with-errors.js",
+    )
+    assert.strictEqual(
+      noErrors?.errorCount,
+      0,
+      JSON.stringify(noErrors, null, 2),
+    )
+    assert.strictEqual(
+      withErrors?.errorCount,
+      3,
+      JSON.stringify(withErrors, null, 2),
+    )
+  })
+
+  it("should not use deprecated rules", async () => {
+    const [javascriptLintResult] = await eslint.lintFiles(
+      "test/fixtures/javascript-no-errors.js",
+    )
+    const [typescriptLintResult] = await eslint.lintFiles(
+      "test/fixtures/typescript-no-errors.ts",
+    )
+    assert.strictEqual(
+      javascriptLintResult.usedDeprecatedRules.length,
+      0,
+      JSON.stringify(javascriptLintResult, null, 2),
+    )
+    assert.strictEqual(
+      typescriptLintResult.usedDeprecatedRules.length,
+      0,
+      JSON.stringify(typescriptLintResult, null, 2),
+    )
+  })
+
+  it("should allow top-level await", async () => {
+    const [lintResult] = await eslint.lintFiles(
+      "test/fixtures/top-level-await.mjs",
+    )
+    assert.strictEqual(
+      lintResult?.errorCount,
+      0,
+      JSON.stringify(lintResult, null, 2),
+    )
+  })
+
+  it("should allow to ignore floating promise with void operator (@typescript-eslint/no-floating-promises)", async () => {
+    const [lintResult] = await eslint.lintFiles(
+      "test/fixtures/typescript-no-errors-ignore-promise.ts",
+    )
+    assert.strictEqual(
+      lintResult?.errorCount,
+      0,
+      JSON.stringify(lintResult, null, 2),
+    )
+  })
+})