https://github.com/kushalshit27/diff-leven
Git like diff between two types, using the Levenshtein distance algorithm
https://github.com/kushalshit27/diff-leven
compare comparison-tool diff js-diff levenshtein levenshtein-distance
Last synced: 4 months ago
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Git like diff between two types, using the Levenshtein distance algorithm
- Host: GitHub
- URL: https://github.com/kushalshit27/diff-leven
- Owner: kushalshit27
- License: mit
- Created: 2025-05-07T11:35:45.000Z (about 1 year ago)
- Default Branch: main
- Last Pushed: 2026-03-10T12:08:32.000Z (5 months ago)
- Last Synced: 2026-03-10T17:36:03.107Z (5 months ago)
- Topics: compare, comparison-tool, diff, js-diff, levenshtein, levenshtein-distance
- Language: TypeScript
- Homepage: https://kushalshit27.github.io/diff-leven/
- Size: 153 KB
- Stars: 0
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
# diff-leven
> Git-like diff between two strings or objects, powered by the Levenshtein distance algorithm
[](https://www.npmjs.com/package/diff-leven)
[](https://www.npmjs.com/package/diff-leven)
[](https://www.jsdelivr.com/package/npm/diff-leven)
[
](https://deepwiki.com/kushalshit27/diff-leven)
**Try now:** [link](https://kushalshit27.github.io/diff-leven/)
---
## ✨ Features
- **Advanced Diff Generation**: Uses the Levenshtein distance algorithm for meaningful diffs
- **Multiple Data Type Support**:
- Objects (including nested structures)
- Arrays (positional comparison; no reordering/LCS)
- Strings (character-level differences)
- Numbers, Booleans, and any serializable value
- **Rich Output Options**:
- Git-style colorized output diff format with clear additions/removals
- **Flexible Configuration**:
- `color`: Toggle color output (default: `true`)
- `keysOnly`: Compare only object structure/keys (default: `false`)
- `full`: Output the entire object tree, not just differences (default: `false`)
- `outputKeys`: Always include specified keys in output for objects with differences
- `ignoreKeys`: Skip specified keys when comparing objects
- `ignoreValues`: Ignore value differences, focus on structure
---
## 🚀 Quick Start
### 1. Install
```bash
npm install diff-leven
```
### 2. Usage
```js
const { diff } = require('diff-leven');
console.log(diff({ foo: 'bar' }, { foo: 'baz' }));
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// }
```
---
## 🛠️ API Reference
### `diff(a, b, options?)`
Compare two values (strings, objects, arrays, etc.) and return a formatted diff string.
> **Note on arrays:** comparison is positional only (index-by-index). Reordered elements are treated as removals/additions rather than matched by similarity.
#### **Parameters**
- `a`, `b`: Anything serializable (object, array, string, number, etc.)
- `options` _(optional object)_:
- `color` _(boolean)_: Use colors in output (default: `true`)
- `keysOnly` _(boolean)_: Only compare object keys (default: `false`)
- `full` _(boolean)_: Output the entire JSON tree (default: `false`)
- `outputKeys` _(string[])_: Always include these keys in output (default: `[]`)
- `ignoreKeys` _(string[])_: Ignore these keys when comparing (default: `[]`)
- `ignoreValues` _(boolean)_: Ignore value differences (default: `false`)
#### **Returns**
- A string representing the diff between `a` and `b`.
### `diffRaw(a, b, options?)`
Compare two values (strings, objects, arrays, etc.) and return a structured diff result object.
#### **Parameters**
- `a`, `b`: Anything serializable (object, array, string, number, etc.)
- `options` _(optional object)_:
- `color` _(boolean)_: Use colors in output (default: `true`)
- `keysOnly` _(boolean)_: Only compare object keys (default: `false`)
- `full` _(boolean)_: Output the entire JSON tree (default: `false`)
- `outputKeys` _(string[])_: Always include these keys in output (default: `[]`)
- `ignoreKeys` _(string[])_: Ignore these keys when comparing (default: `[]`)
- `ignoreValues` _(boolean)_: Ignore value differences (default: `false`)
#### **Returns**
- A structured object representing the diff between `a` and `b`.
### `isDiff(a, b, options?)`
Check if two values (strings, objects, arrays, etc.) are different and return a boolean result.
#### **Parameters**
- `a`, `b`: Anything serializable (object, array, string, number, etc.)
- `options` _(optional object)_:
- `keysOnly` _(boolean)_: Only compare object keys (default: `false`)
- `ignoreKeys` _(string[])_: Ignore these keys when comparing (default: `[]`)
- `ignoreValues` _(boolean)_: Ignore value differences (default: `false`)
#### **Returns**
- A boolean indicating if the values are different (`true` = different, `false` = identical).
#### **Examples**
```js
const { diff, diffRaw, isDiff } = require('diff-leven');
// Basic diff (string output)
console.log(diff({ foo: 'bar' }, { foo: 'baz' }));
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// }
// Raw diff object
const rawDiff = diffRaw({ foo: 'bar' }, { foo: 'baz' });
console.log(JSON.stringify(rawDiff, null, 2));
// Output:
// {
// "type": "changed",
// "path": [],
// "oldValue": { "foo": "bar" },
// "newValue": { "foo": "baz" },
// "children": [
// {
// "type": "changed",
// "path": ["foo"],
// "oldValue": "bar",
// "newValue": "baz"
// }
// ]
// }
// Boolean diff check
console.log(isDiff({ foo: 'bar' }, { foo: 'baz' }));
// Output: true
console.log(isDiff({ foo: 'bar' }, { foo: 'bar' }));
// Output: false
// With options
console.log(
isDiff(
{ foo: 'bar', timestamp: 123 },
{ foo: 'bar', timestamp: 456 },
{ ignoreKeys: ['timestamp'] },
),
);
// Output: false (identical when ignoring timestamp)
// No colors
console.log(diff({ foo: 'bar' }, { foo: 'baz' }, { color: false }));
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// }
// Full output
console.log(diff({ foo: 'bar', b: 3 }, { foo: 'baz', b: 3 }, { full: true }));
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// b: 3
// }
// Ignore keys
console.log(
diff({ foo: 'bar', b: 3 }, { foo: 'baz', b: 3 }, { ignoreKeys: ['b'] }),
);
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// }
// Ignore values
console.log(
diff({ foo: 'bar', b: 3 }, { foo: 'baz', b: 3 }, { ignoreValues: true }),
);
// Output showing structural differences only
// Show similarity info for string changes
console.log(
diff('hello world', 'hello there', { color: true, withSimilarity: true }),
);
// Output:
// - 'hello world'
// + 'hello there' (73% similar)
// Output specific keys
console.log(
diff({ foo: 'bar', b: 3 }, { foo: 'baz', b: 3 }, { outputKeys: ['foo'] }),
);
// Output:
// {
// - foo: "bar"
// + foo: "baz"
// }
// Combine options
console.log(
diff(
{ foo: 'bar', b: 3 },
{ foo: 'baz', b: 3 },
{
keysOnly: true,
ignoreKeys: ['b'],
ignoreValues: true,
outputKeys: ['foo'],
full: true,
color: false,
},
),
);
```
---
## ⚙️ Options Matrix
| Option | Type | Default | Description |
| ---------------- | -------- | ------- | -------------------------------------------- |
| `color` | boolean | true | Use colorized output |
| `keysOnly` | boolean | false | Only compare object keys |
| `full` | boolean | false | Output the entire object tree |
| `outputKeys` | string[] | [] | Always include these keys in output |
| `ignoreKeys` | string[] | [] | Ignore these keys when comparing |
| `ignoreValues` | boolean | false | Ignore value differences, focus on structure |
| `withSimilarity` | boolean | false | Show similarity info for string changes |
---
## 📦 Examples
See [`examples/basic.js`](examples/basic.js) for more usage patterns.
---
## 🤝 Contributing
1. Fork the repo
2. Create your feature branch (`git checkout -b feature/YourFeature`)
3. Commit your changes (`git commit -am 'Add new feature'`)
4. Push to the branch (`git push origin feature/YourFeature`)
5. Open a pull request
---
## 📄 License
MIT © [kushalshit27](LICENSE)