Property Tools

This module contains helper functions for getting, setting, and requiring both shallow and deep properties in objects.

Building

If you want to build it for the browser then do this:

cd /your/path/property-tools
npm install
npm build

or

npm build-min

To build the tests:

npm run build-test

Testing

To test the code in a shell:

npm run test

To test the code in a browser, first do this:

npm run server

Then point your browser to whatever url is printed to the shell. Most likely it will be this:

http://127.0.0.1:8080

Developing

To automatically lint, build, and test whenever you edit the code, do this:

npm run watch

Using

The package exports these functions:

const {
  getProperty,
  requireProperty,
  setProperty,
  getErrorHandler,
  setErrorHandler,
  callErrorHandler,
  getVersion
} = require ( "property-tools" );

Get Version

Get the version:

assert.deepEqual ( getVersion(), { major: 1, minor: 0, patch: 0 } );

Get Property

Getting a property that exists:

assert.equal ( getProperty ( { a: 1 }, "a" ), 1 );

Getting a property that does not exist just returns the default value:

const a = { b: 1 };
assert.equal ( getProperty ( a, "c" ), undefined );
assert.equal ( getProperty ( a, "c", 10 ), 10 );

Getting a property from an invalid container object just returns the default value:

assert.equal ( getProperty ( null, "p" ), undefined );
assert.equal ( getProperty ( null, "p", 10 ), 10 );

Require Property

Requiring a property that exists:

assert.equal ( requireProperty ( { a: 1 }, "a" ), 1 );

Requiring a property that does not exist will throw an exception:

expect ( function() { requireProperty ( { b: 1 }, "c" ); } )
  .to.throw ( Error, "Property 'c' not in object" );

Requiring a property from an invalid container object will throw an exception:

expect ( function() { requireProperty ( null, "p" ); } )
  .to.throw ( Error, "Invalid container object" );