Package Exports
- subzero
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Readme
#subzero 
##About:
Freeze a class, freeze a function, or freeze an object.
##install:
npm install subzero##usage:
####function list (each function explained in more detail below):
Note: the deep freeze function was inspired by MDN. The mega freeze function was inspired by deep-freeze.
####No-op If the input value is not an object, a function, or a class for any of subzero's functions, the return value will be the input value unaltered.
###1) subzero.freeze( functionOrClassOrObjectToFreeze ) Freeze a class or a function and its prototype. For object input, it acts the exact same way as Object.freeze.
'use strict';
const subzero = require( 'subzero' );
/*
this example uses a class, subzero.freeze also works
with objects and functions
*/
class C {
static f() { return 69; }
f() { return 22; }
}
const reference = subzero.freeze( C );
/*
the following statements will now return true:
*/
// ( reference === C );
// Object.isFrozen( C );
// Object.isFrozen( C.prototype );
/*
as a result the following statements will now throw TypeErrors in strict mode:
*/
// C.g = function() { return 42 };
// C.f = function() { return 42 };
// delete C.f;
// C.constant = 42;
// C.prototype.g = function() { return 42 };
// C.prototype.f = function() { return 42 };
// delete C.prototype.f;
// C.prototype.constant = 42;
❄️🎅🏿🎅🏽🎅🏾🎅🏼⛄️🎿🗻🏂
###2) subzero.deepFreeze( functionOrClassOrObjectToFreeze )
Deep freeze a class, an object, or a function. This will not freeze any classes or functions within the input object/function/class. It works by recursively freezing anything of type "object".
'use strict';
const subzero = require( 'subzero' );
/*
this example uses an object, subzero.deepFreeze also works
with functions and classes
*/
const o = {};
class InnerClass {}
InnerClass.x = {
y: {}
};
function innerFunction() {}
innerFunction.x = {
y: {}
};
const willBeFrozen = {};
o.a = {
b: {
c: {
d: {
InnerClass,
innerFunction,
e: Object.freeze({ willBeFrozen })
}
}
}
};
o.x = {
y: {
z: {}
},
w: {}
};
const reference = subzero.deepFreeze( o );
/*
the following statements will now return true:
*/
// ( reference === o );
// Object.isFrozen( o );
// Object.isFrozen( o.a );
// Object.isFrozen( o.a.b );
// Object.isFrozen( o.a.b.c );
// Object.isFrozen( o.a.b.c.d );
// Object.isFrozen( o.x );
// Object.isFrozen( o.x.y );
// Object.isFrozen( o.x.y.z );
// Object.isFrozen( o.x.w );
// !Object.isFrozen( InnerClass );
// !Object.isFrozen( InnerClass.x );
// !Object.isFrozen( InnerClass.x.y );
// !Object.isFrozen( innerFunction );
// !Object.isFrozen( innerFunction.x );
// !Object.isFrozen( innerFunction.x.y );
// Object.isFrozen( willBeFrozen );
###3) subzero.megaFreeze( functionOrClassOrObjectToFreeze )
Deep freeze a class, an object, or a function. This will freeze any classes, functions, and objects within the class. It works by recursively freezing anything of type "object" or "function", if they are unfrozen. Note the * MEGA FREEZE CORNER CASE.
'use strict';
/*
this example uses a function, subzero.megaFreeze also works
with objects and classes
*/
function f() {}
class InnerClass {};
InnerClass.x = {
y: {}
};
const innerFunction = function() {};
innerFunction.x = {
y: {}
};
/* MEGA FREEZE CORNER CASE:
be careful about objects/functions within already frozen objects and functions
*/
const wontBeFrozen = {};
f.a = {
b: {
c: {
d: {
InnerClass,
innerFunction,
e: Object.freeze({ wontBeFrozen })
}
}
}
};
f.prototype.x = {
y: {
z: {}
},
w: {}
};
const reference = subzero.megaFreeze( f );
/*
the following statements will now return true:
*/
// ( reference === f );
// Object.isFrozen( f );
// Object.isFrozen( f.a );
// Object.isFrozen( f.a.b );
// Object.isFrozen( f.a.b.c );
// Object.isFrozen( f.a.b.c.d );
// Object.isFrozen( f.prototype );
// Object.isFrozen( f.prototype.x );
// Object.isFrozen( f.prototype.x.y );
// Object.isFrozen( f.prototype.x.y.z );
// Object.isFrozen( f.prototype.x.w );
// Object.isFrozen( InnerClass );
// Object.isFrozen( InnerClass.prototype );
// Object.isFrozen( InnerClass.x );
// Object.isFrozen( InnerClass.x.y );
// Object.isFrozen( innerFunction );
// Object.isFrozen( innerFunction.x );
// Object.isFrozen( innerFunction.x.y );
// Object.isFrozen( innerFunction.prototype );
// !Object.isFrozen( wontBeFrozen );