198 lines
		
	
	
	
		
			6.6 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			198 lines
		
	
	
	
		
			6.6 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# object-hash
 | 
						|
 | 
						|
Generate hashes from objects and values in node and the browser.  Uses node.js
 | 
						|
crypto module for hashing.  Supports SHA1 and many others (depending on the platform)
 | 
						|
as well as custom streams (e.g. CRC32).
 | 
						|
 | 
						|
[](https://www.npmjs.com/package/object-hash)
 | 
						|
 | 
						|
[](https://secure.travis-ci.org/puleos/object-hash?branch=master)
 | 
						|
[](https://coveralls.io/github/puleos/object-hash?branch=master)
 | 
						|
 | 
						|
* Hash values of any type.
 | 
						|
* Supports a keys only option for grouping similar objects with different values.
 | 
						|
 | 
						|
```js
 | 
						|
var hash = require('object-hash');
 | 
						|
 | 
						|
hash({foo: 'bar'}) // => '67b69634f9880a282c14a0f0cb7ba20cf5d677e9'
 | 
						|
hash([1, 2, 2.718, 3.14159]) // => '136b9b88375971dff9f1af09d7356e3e04281951'
 | 
						|
```
 | 
						|
 | 
						|
## Versioning Disclaimer
 | 
						|
 | 
						|
Starting with version `1.1.8` (released April 2017), new versions will consider
 | 
						|
the exact returned hash part of the API contract, i.e. changes that will affect
 | 
						|
hash values will be considered `semver-major`. Previous versions may violate
 | 
						|
that expectation.
 | 
						|
 | 
						|
For more information, see [this discussion](https://github.com/puleos/object-hash/issues/30).
 | 
						|
 | 
						|
## hash(value, options)
 | 
						|
 | 
						|
Generate a hash from any object or type.  Defaults to sha1 with hex encoding.
 | 
						|
 | 
						|
* `algorithm` hash algo to be used: 'sha1', 'md5', 'passthrough'. default: sha1
 | 
						|
  * This supports the algorithms returned by `crypto.getHashes()`. Note that the default of SHA-1 is not considered secure, and a stronger algorithm should be used if a cryptographical hash is desired.
 | 
						|
  * This also supports the `passthrough` algorith, which will return the information that would otherwise have been hashed.
 | 
						|
* `excludeValues` {true|false} hash object keys, values ignored. default: false
 | 
						|
* `encoding` hash encoding, supports 'buffer', 'hex', 'binary', 'base64'. default: hex
 | 
						|
* `ignoreUnknown` {true|*false} ignore unknown object types. default: false
 | 
						|
* `replacer` optional function that replaces values before hashing. default: accept all values
 | 
						|
* `respectFunctionProperties` {true|false} Whether properties on functions are considered when hashing. default: true
 | 
						|
* `respectFunctionNames` {true|false} consider `name` property of functions for hashing. default: true
 | 
						|
* `respectType` {true|false} Whether special type attributes (`.prototype`, `.__proto__`, `.constructor`)
 | 
						|
   are hashed. default: true
 | 
						|
* `unorderedArrays` {true|false} Sort all arrays before hashing. Note that this affects *all* collections,
 | 
						|
   i.e. including typed arrays, Sets, Maps, etc. default: false
 | 
						|
* `unorderedSets` {true|false} Sort `Set` and `Map` instances before hashing, i.e. make
 | 
						|
  `hash(new Set([1, 2])) == hash(new Set([2, 1]))` return `true`. default: true
 | 
						|
* `unorderedObjects` {true|false} Sort objects before hashing, i.e. make `hash({ x: 1, y: 2 }) === hash({ y: 2, x: 1 })`. default: true
 | 
						|
* `excludeKeys` optional function for excluding specific key(s) from hashing, if true is returned then exclude from hash. default: include all keys
 | 
						|
 | 
						|
## hash.sha1(value)
 | 
						|
 | 
						|
Hash using the sha1 algorithm.
 | 
						|
 | 
						|
Note that SHA-1 is not considered secure, and a stronger algorithm should be used if a cryptographical hash is desired.
 | 
						|
 | 
						|
*Sugar method, equivalent to* `hash(value, {algorithm: 'sha1'})`
 | 
						|
 | 
						|
## hash.keys(value)
 | 
						|
 | 
						|
Hash object keys using the sha1 algorithm, values ignored.
 | 
						|
 | 
						|
*Sugar method, equivalent to* `hash(value, {excludeValues: true})`
 | 
						|
 | 
						|
## hash.MD5(value)
 | 
						|
 | 
						|
Hash using the md5 algorithm.
 | 
						|
 | 
						|
Note that the MD5 algorithm is not considered secure, and a stronger algorithm should be used if a cryptographical hash is desired.
 | 
						|
 | 
						|
*Sugar method, equivalent to* `hash(value, {algorithm: 'md5'})`
 | 
						|
 | 
						|
## hash.keysMD5(value)
 | 
						|
 | 
						|
Hash object keys using the md5 algorithm, values ignored.
 | 
						|
 | 
						|
Note that the MD5 algorithm is not considered secure, and a stronger algorithm should be used if a cryptographical hash is desired.
 | 
						|
 | 
						|
*Sugar method, equivalent to* `hash(value, {algorithm: 'md5', excludeValues: true})`
 | 
						|
 | 
						|
## hash.writeToStream(value, [options,] stream)
 | 
						|
 | 
						|
Write the information that would otherwise have been hashed to a stream, e.g.:
 | 
						|
 | 
						|
```js
 | 
						|
hash.writeToStream({foo: 'bar', a: 42}, {respectType: false}, process.stdout)
 | 
						|
// => e.g. 'object:a:number:42foo:string:bar'
 | 
						|
```
 | 
						|
 | 
						|
## Installation
 | 
						|
 | 
						|
node:
 | 
						|
 | 
						|
```js
 | 
						|
npm install object-hash
 | 
						|
```
 | 
						|
 | 
						|
browser: */dist/object_hash.js*
 | 
						|
 | 
						|
```html
 | 
						|
<script src="object_hash.js" type="text/javascript"></script>
 | 
						|
 | 
						|
<script>
 | 
						|
  var hash = objectHash.sha1({foo:'bar'});
 | 
						|
 | 
						|
  console.log(hash); // e003c89cdf35cdf46d8239b4692436364b7259f9
 | 
						|
</script>
 | 
						|
```
 | 
						|
 | 
						|
## Example usage
 | 
						|
 | 
						|
```js
 | 
						|
var hash = require('object-hash');
 | 
						|
 | 
						|
var peter = { name: 'Peter', stapler: false, friends: ['Joanna', 'Michael', 'Samir'] };
 | 
						|
var michael = { name: 'Michael', stapler: false, friends: ['Peter', 'Samir'] };
 | 
						|
var bob = { name: 'Bob', stapler: true, friends: [] };
 | 
						|
 | 
						|
/***
 | 
						|
 * sha1 hex encoding (default)
 | 
						|
 */
 | 
						|
hash(peter);
 | 
						|
// 14fa461bf4b98155e82adc86532938553b4d33a9
 | 
						|
hash(michael);
 | 
						|
// 4b2b30e27699979ce46714253bc2213010db039c
 | 
						|
hash(bob);
 | 
						|
// 38d96106bc8ef3d8bd369b99bb6972702c9826d5
 | 
						|
 | 
						|
/***
 | 
						|
 * hash object keys, values ignored
 | 
						|
 */
 | 
						|
hash(peter, { excludeValues: true });
 | 
						|
// 48f370a772c7496f6c9d2e6d92e920c87dd00a5c
 | 
						|
hash(michael, { excludeValues: true });
 | 
						|
// 48f370a772c7496f6c9d2e6d92e920c87dd00a5c
 | 
						|
hash.keys(bob);
 | 
						|
// 48f370a772c7496f6c9d2e6d92e920c87dd00a5c
 | 
						|
 | 
						|
/***
 | 
						|
 * hash object, ignore specific key(s)
 | 
						|
 */
 | 
						|
hash(peter, { excludeKeys: function(key) {
 | 
						|
    if ( key === 'friends') {
 | 
						|
      return true;
 | 
						|
    }
 | 
						|
    return false;
 | 
						|
  }
 | 
						|
});
 | 
						|
// 66b7d7e64871aa9fda1bdc8e88a28df797648d80
 | 
						|
 | 
						|
/***
 | 
						|
 * md5 base64 encoding
 | 
						|
 */
 | 
						|
hash(peter, { algorithm: 'md5', encoding: 'base64' });
 | 
						|
// 6rkWaaDiG3NynWw4svGH7g==
 | 
						|
hash(michael, { algorithm: 'md5', encoding: 'base64' });
 | 
						|
// djXaWpuWVJeOF8Sb6SFFNg==
 | 
						|
hash(bob, { algorithm: 'md5', encoding: 'base64' });
 | 
						|
// lFzkw/IJ8/12jZI0rQeS3w==
 | 
						|
```
 | 
						|
 | 
						|
## Legacy Browser Support
 | 
						|
 | 
						|
IE <= 8 and Opera <= 11 support dropped in version 0.3.0.  If you require
 | 
						|
legacy browser support you must either use an ES5 shim or use version 0.2.5
 | 
						|
of this module.
 | 
						|
 | 
						|
## Development
 | 
						|
 | 
						|
```sh-session
 | 
						|
git clone https://github.com/puleos/object-hash
 | 
						|
```
 | 
						|
 | 
						|
## Node Docker Wrapper
 | 
						|
 | 
						|
If you want to stand this up in a docker container, you should take at look
 | 
						|
at the [](https://github.com/bean5/node-object-hash) project.
 | 
						|
 | 
						|
### gulp tasks
 | 
						|
 | 
						|
* `gulp watch` (default) watch files, test and lint on change/add
 | 
						|
* `gulp test` unit tests
 | 
						|
* `gulp karma` browser unit tests
 | 
						|
* `gulp lint` jshint
 | 
						|
* `gulp dist` create browser version in /dist
 | 
						|
 | 
						|
## License
 | 
						|
 | 
						|
MIT
 | 
						|
 | 
						|
## Changelog
 | 
						|
 | 
						|
### v2.0.0
 | 
						|
 | 
						|
Only Node.js versions `>= 6.0.0` are being tested in CI now.
 | 
						|
No other breaking changes were introduced.
 |