Security News
Introducing the Socket Python SDK
The initial version of the Socket Python SDK is now on PyPI, enabling developers to more easily interact with the Socket REST API in Python projects.
Enhances a JavaScript class by adding an is<Class> property to compare types between realms.
Enhances a JavaScript class by adding an is<Class>
property to compare types between realms.
Checking if a value is an instance of a class in JavaScript is not an easy task.
You can use instanceof
, but that doesn't work between different realms or different versions. Comparing with constructor.name
could be a solution but if you need to Uglify the module it doesn't work, as it creates different names for the same module.
Symbols to the rescue!
$ npm install class-is
If you want to use this module in the browser you have to compile it yourself to your desired target.
// Package X
const withIs = require('class-is');
class Person {
constructor(name, city) {
this.name = name;
this.city = city;
}
}
module.exports = withIs(Person, {
className: 'Person',
symbolName: '@org/package-x/Person',
});
// Package Y
const withIs = require('class-is');
class Animal {
constructor(species) {
this.species = species;
}
}
module.exports = withIs(Animal, {
className: 'Animal',
symbolName: '@org/package-y/Animal',
});
const Person = require('package-x');
const Animal = require('package-y');
const diogo = new Person('Diogo', 'Porto');
const wolf = new Animal('Gray Wolf');
console.log(Person.isPerson(diogo));
console.log(Person.isPerson(wolf));
Running the example above will print:
true
false
In ES5 it's not unusual to see constructors like the one below, so you can call it without using the new
keyword.
function Circle(radius) {
if (!(this instanceof Circle)) {
return new Circle();
}
this.radius = radius;
}
In such cases you can use the withIs.proto
method:
const withIs = require('class-is');
const Circle = withIs.proto(function (radius) {
if (!(this instanceof Circle)) {
return new Circle();
}
this.radius = radius;
}, {
className: 'Circle',
symbolName: '@org/package/Circle',
});
...or even better:
const withIs = require('class-is');
function Circle(radius) {
this.radius = radius;
}
module.exports = withIs.proto(Circle, {
className: 'Circle',
symbolName: '@org/package/Circle',
withoutNew: true,
});
Type: class
The class to be enhanced.
Type: String
The name of the class your passing.
Type: String
Unique id for the class. This should be namespaced so different classes from different modules do not collide and give false positives.
Example: @organization/package/Class
The className
and symbolName
parameters are the same as above.
Type: Boolean
Default: false
Allow creating an instance without the new
operator.
$ npm test
$ npm test -- --watch
during development
FAQs
Enhances a JavaScript class by adding an is<Class> property to compare types between realms.
The npm package class-is receives a total of 206,040 weekly downloads. As such, class-is popularity was classified as popular.
We found that class-is demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 20 open source maintainers collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
The initial version of the Socket Python SDK is now on PyPI, enabling developers to more easily interact with the Socket REST API in Python projects.
Security News
Floating dependency ranges in npm can introduce instability and security risks into your project by allowing unverified or incompatible versions to be installed automatically, leading to unpredictable behavior and potential conflicts.
Security News
A new Rust RFC proposes "Trusted Publishing" for Crates.io, introducing short-lived access tokens via OIDC to improve security and reduce risks associated with long-lived API tokens.