Revert "docs(readme): simplify and condense content"

This reverts commit 4071dfb.

Author: evaliyev

README.md

@@ -1,50 +1,240 @@
 # has-jsx
 
-Detect JSX in files and strings using AST analysis via [ast-grep](https://github.com/ast-grep/ast-grep). No false positives from TypeScript generics or angle brackets.
+CLI and programmatic tool to detect JSX in files and strings using AST analysis.
+
+## Why has-jsx?
+
+Detecting JSX isn't as simple as checking file extensions. JavaScript and TypeScript files (`.js`, `.ts`) can contain JSX syntax. This tool uses [ast-grep](https://github.com/ast-grep/ast-grep)'s powerful AST parsing to reliably detect JSX node types from the [JSX specification](https://facebook.github.io/jsx/):
+
+- `jsx_element` - Standard tags: `<div>...</div>`
+- `jsx_self_closing_element` - Self-closing: `<Component />`
+- `jsx_fragment` - Fragments: `<>...</>`
+
+## Features
+
+- ✅ **Dual mode:** Check files or strings directly
+- ✅ **Dual package:** Works with both ESM (`import`) and CommonJS (`require()`)
+- ✅ **AST-based:** No false positives from TypeScript generics or comparison operators
+- ✅ **CLI & API:** Use from command line or programmatically
+- ✅ **Fast & reliable:** Powered by ast-grep
 
 ## Installation
 
 ```bash
 npm install has-jsx
+# or
+pnpm add has-jsx
+```
+
+## CLI Usage
+
+### Check Files
+
+Use the `-f` or `--file` flag to check files:
+
+```bash
+has-jsx -f src/Component.tsx
+# Output: JSX detected
+# Exit code: 0
+
+has-jsx --file src/utils.ts
+# Output: No JSX detected
+# Exit code: 1
+```
+
+### Check Strings
+
+Pass source code directly without any flags:
+
+```bash
+has-jsx "const App = () => <div>Hello</div>"
+# Output: JSX detected
+# Exit code: 0
+
+has-jsx "const x = 5;"
+# Output: No JSX detected
+# Exit code: 1
 ```
 
-## CLI
+### Options
+
+#### Verbose Mode
+
+Get detailed JSON output:
+
+```bash
+has-jsx --verbose -f src/App.jsx
+# Output:
+# {
+#   "hasJSX": true,
+#   "inputType": "file",
+#   "file": "src/App.jsx"
+# }
+
+has-jsx --verbose "<Button />"
+# Output:
+# {
+#   "hasJSX": true,
+#   "inputType": "string",
+#   "source": "<Button />"
+# }
+```
+
+#### Quiet Mode
+
+Silent mode with only exit codes (useful for scripts):
+
+```bash
+has-jsx --quiet src/file.js
+echo $?  # 0 if JSX detected, 1 if not, 2 on error
+```
+
+#### Version
 
 ```bash
-has-jsx -f src/Component.tsx    # Check a file
-has-jsx "<div>Hello</div>"      # Check a string
-has-jsx --verbose -f src/App.jsx  # JSON output
-has-jsx --quiet src/file.js     # Silent, exit code only
+has-jsx --version
 ```
 
-**Exit codes:** 0 = JSX detected, 1 = no JSX, 2 = error
+### Exit Codes
+
+- **0** - JSX detected
+- **1** - No JSX detected
+- **2** - Error (file not found, read error, etc.)
+
+## Programmatic API
+
+### File-based Detection
 
-## API
+Check if a file contains JSX:
 
+**ESM (recommended):**
 ```javascript
-import hasJSX, { hasJSXInString } from 'has-jsx';
+import hasJSX from 'has-jsx';
 
-// File (async)
-await hasJSX('src/Component.tsx'); // true | false
+const result = await hasJSX('src/Component.tsx');
+console.log(result); // true or false
+```
+
+**CommonJS:**
+```javascript
+const { hasJSX } = require('has-jsx');
 
-// String (sync)
-hasJSXInString('<Button />'); // true
+(async () => {
+  const result = await hasJSX('src/Component.tsx');
+  console.log(result);
+})();
 ```
 
-### `hasJSX(filepath: string): Promise<boolean>`
+### String-based Detection
 
-Reads and parses a file. Throws if the file doesn't exist or can't be read.
+Check if a string contains JSX (synchronous, no file I/O):
 
-### `hasJSXInString(source: string): boolean`
+**ESM:**
+```javascript
+import { hasJSXInString } from 'has-jsx';
 
-Parses a source string synchronously. Throws `TypeError` if source is not a string.
+const code = `
+  function App() {
+    return <div>Hello World</div>;
+  }
+`;
 
-Both work with ESM (`import`) and CommonJS (`require`).
+const result = hasJSXInString(code);
+console.log(result); // true
+```
+
+**CommonJS:**
+```javascript
+const { hasJSXInString } = require('has-jsx');
+
+const code = 'const App = () => <div>Hello</div>';
+const result = hasJSXInString(code);
+console.log(result); // true
+```
+
+### API Reference
+
+#### `hasJSX(filepath: string): Promise<boolean>`
+
+Analyzes a file to detect JSX syntax.
+
+**Parameters:**
+- `filepath` - Path to the file to analyze (relative or absolute)
+
+**Returns:**
+- `Promise<boolean>` - `true` if JSX is detected, `false` otherwise
+
+**Throws:**
+- `Error` - If file doesn't exist, is not a file, or can't be read
+
+**Example:**
+
+```javascript
+import hasJSX from 'has-jsx';
+
+try {
+  const result = await hasJSX('src/Component.tsx');
+  if (result) {
+    console.log('This file contains JSX');
+  }
+} catch (error) {
+  console.error('Error:', error.message);
+}
+```
+
+#### `hasJSXInString(source: string): boolean`
+
+Analyzes a source code string to detect JSX syntax (synchronous).
+
+**Parameters:**
+- `source` - Source code string to analyze
+
+**Returns:**
+- `boolean` - `true` if JSX is detected, `false` otherwise
+
+**Throws:**
+- `TypeError` - If source is not a string
+
+**Example:**
+
+```javascript
+import { hasJSXInString } from 'has-jsx';
+
+const code = 'const Button = () => <button>Click</button>';
+const result = hasJSXInString(code);
+console.log(result); // true
+
+// No false positives for TypeScript generics
+const genericCode = 'function identity<T>(arg: T): T { return arg; }';
+console.log(hasJSXInString(genericCode)); // false
+```
+
+## How It Works
+
+1. **AST Parsing**: Uses [ast-grep](https://github.com/ast-grep/ast-grep) to parse files as TypeScript/TSX
+2. **Node Detection**: Searches the AST for JSX-specific node types defined in the [JSX specification](https://facebook.github.io/jsx/)
+3. **Reliable Results**: Avoids false positives from regex-based detection or angle brackets in comparisons
+
+## Use Cases
+
+- **Build Tools**: Determine which files need JSX transformation
+- **Linters**: Validate JSX usage against project rules
+- **Code Analysis**: Audit codebase for JSX patterns
+- **CI/CD**: Verify file types in automated pipelines
+- **Migration Tools**: Identify files during framework migrations
 
 ## Requirements
 
-Node.js >= 20.0.0
+- Node.js >= 20.0.0
 
 ## License
 
 MIT
+
+## Contributing
+
+Issues and pull requests welcome! Please ensure all tests pass before submitting:
+
+```bash
+npm test
+```