feat: add error generic type parameter and upgrade dependencies

.github/workflows/ci.yml

@@ -0,0 +1,44 @@
+name: CI
+
+on:
+  push:
+    branches: [ main, master ]
+  pull_request:
+    branches: [ main, master ]
+
+jobs:
+  test:
+    name: Test on Node.js ${{ matrix.node-version }}
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [20.x, 22.x]
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Use Node.js ${{ matrix.node-version }}
+      uses: actions/setup-node@v4
+      with:
+        node-version: ${{ matrix.node-version }}
+        cache: 'npm'
+
+    - name: Install dependencies
+      run: npm ci --legacy-peer-deps
+
+    - name: Run linter
+      run: npm run lint:scripts
+
+    - name: Run tests
+      run: npm test
+
+    - name: Build
+      run: npm run build
+
+    - name: Upload coverage
+      if: matrix.node-version == '20.x'
+      uses: codecov/codecov-action@v4
+      continue-on-error: true
+      with:
+        fail_ci_if_error: false

.github/workflows/publish.yml

@@ -0,0 +1,35 @@
+name: Publish to npm
+
+on:
+  release:
+    types: [created]
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    permissions:
+      contents: read
+      id-token: write
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Setup Node.js
+      uses: actions/setup-node@v4
+      with:
+        node-version: '20.x'
+        registry-url: 'https://registry.npmjs.org'
+
+    - name: Install dependencies
+      run: npm ci --legacy-peer-deps
+
+    - name: Run tests
+      run: npm test
+
+    - name: Build
+      run: npm run build
+
+    - name: Publish to npm
+      run: npm publish --access public --provenance
+      env:
+        NODE_AUTH_TOKEN: ${{ secrets.NPM_TOKEN }}

CHANGELOG.md

@@ -0,0 +1,44 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
+
+## [1.4.0] - 2025-11-15
+
+### Added
+- **Generic error type parameter**: You can now specify custom error types for both `attempt` and `attemptPromise`
+  - Both functions now accept two type parameters: `<T, E = Error>`
+  - The error type defaults to `Error` for backward compatibility
+  - Example: `attempt<User, ValidationError>(() => ...)`
+- Package metadata:
+  - `sideEffects: false` for better tree-shaking support
+  - `engines` field specifying Node.js ^20.19.0 || >=22.12.0
+
+### Changed
+- **Major dependency upgrades**:
+  - ESLint: 8.54.0 → 9.39.1 (migrated to flat config format)
+  - TypeScript: 5.3.2 → 5.9.3
+  - Vite: 5.0.2 → 7.2.2
+  - Vitest: 0.34.6 → 4.0.9
+  - Prettier: 2.8.8 → 3.6.2
+  - All other dev dependencies updated to latest versions
+- Build tooling:
+  - Migrated ESLint configuration from `.eslintrc.json` to `eslint.config.js` (flat config)
+  - Updated package.json exports order (types before import/require)
+  - Replaced deprecated `@vitest/coverage-c8` with `@vitest/coverage-v8`
+
+### Fixed
+- Package.json exports now list types first for better IDE support
+
+## [1.3.9] - Previous release
+
+### Changed
+- Type export improvements
+- CJS package fixes
+
+## [1.2.x] - Previous releases
+
+### Removed
+- `attemptAllPromise` function (caused confusion, may be replaced with better implementation in future)

ReadMe.md

@@ -38,6 +38,58 @@ attemptPromise(fn).then(([error, result]) => {
 });
 ```
 
+### TypeScript Support
+
+As of v1.4.0, you can now type both the result **and** the error with custom types:
+
+#### Basic TypeScript usage
+
+```typescript
+import { attempt, attemptPromise } from '@jfdi/attempt';
+
+// Type just the result (error defaults to Error)
+const [error, result] = attempt<string>(() => "success");
+
+// Type both result and error
+class ValidationError extends Error {
+    code: number;
+}
+
+const [error, result] = attempt<User, ValidationError>(() => {
+    // your code here
+});
+
+// Now TypeScript knows:
+// - error is ValidationError | undefined
+// - result is User | undefined
+```
+
+#### Async with custom error types
+
+```typescript
+const [error, data] = await attemptPromise<ApiResponse, ApiError>(
+    async () => await fetchData()
+);
+
+if (error) {
+    // error is typed as ApiError
+    console.error(error.statusCode, error.message);
+} else {
+    // data is typed as ApiResponse
+    console.log(data.results);
+}
+```
+
+#### Backward compatibility
+
+The error type parameter defaults to `Error`, so existing code continues to work without changes:
+
+```typescript
+// These are equivalent:
+const [err, res] = attempt<string>(() => "hello");
+const [err, res] = attempt<string, Error>(() => "hello");
+```
+
 ### Examples?
 
 See the tests. They're pretty comprehensive.

eslint.config.js

@@ -0,0 +1,46 @@
+import globals from "globals";
+import js from "@eslint/js";
+import tseslint from "@typescript-eslint/eslint-plugin";
+import tsparser from "@typescript-eslint/parser";
+import prettierConfig from "eslint-config-prettier";
+import prettierPlugin from "eslint-plugin-prettier";
+
+export default [
+    js.configs.recommended,
+    {
+        files: ["**/*.ts", "**/*.js"],
+        languageOptions: {
+            ecmaVersion: 2020,
+            sourceType: "module",
+            globals: {
+                ...globals.node,
+                ...globals.es6,
+                Atomics: "readonly",
+                SharedArrayBuffer: "readonly"
+            },
+            parser: tsparser,
+            parserOptions: {
+                ecmaVersion: 2020
+            }
+        },
+        plugins: {
+            "@typescript-eslint": tseslint,
+            prettier: prettierPlugin
+        },
+        rules: {
+            "prettier/prettier": [
+                "warn",
+                {
+                    endOfLine: "auto"
+                }
+            ],
+            "no-unused-vars": "off",
+            "@typescript-eslint/no-unused-vars": "warn",
+            "no-console": "off",
+            "no-extra-semi": "warn",
+            "no-extra-boolean-cast": "warn",
+            "no-undef": "off" // TypeScript handles this
+        }
+    },
+    prettierConfig
+];