arrow function

hasAttribute.ts

// check if "x" have attribute "attr" with option to return it
const haveAttr = (x: any, attr: string, returnVal?: boolean): boolean | any => !x ? false : !x.hasOwnProperty(attr) ? false : returnVal ? x[attr] : true;
const isArray = (x: any): boolean => (!!x) && (x.constructor === Array);
const isObject = (x: any): boolean => (!!x) && (x.constructor === Object);
const isDate = (x: any): boolean => (!!x) && (x.constructor === Date);


const assert = (result, mustbe: any, name: string, check: any) =>
    result === mustbe ?
    console.log(`Success: ${name}, check ${check} is ${mustbe}`) :
    console.log(`-----Error-----: ${name}, check ${check} is ${mustbe}`);


console.log('\n');

assert(haveAttr(null, 'name'), false, 'haveAttr(null, "name")', null);
assert(haveAttr(undefined, 'name'), false, 'haveAtt', undefined);
assert(haveAttr({}, 'name'), false, 'haveAtt', JSON.stringify({}));
assert(haveAttr({wrong: true}, 'name'), false, 'haveAtt', JSON.stringify({wrong: true}));
assert(haveAttr({Name: true}, 'name'), false, 'haveAtt', JSON.stringify({Name: true}));
assert(haveAttr({name: undefined}, 'name'), true, 'haveAtt', JSON.stringify({name: undefined}) + ' att have undefined value...so only showing {}');
assert(haveAttr({name: false}, 'name'), true, 'haveAtt', JSON.stringify({name: false}));
assert(haveAttr({name: null}, 'name'), true, 'haveAtt', JSON.stringify({name: null}));
assert(haveAttr(new Date(), 'name'), false, 'haveAtt', JSON.stringify(new Date()));
assert(haveAttr([], 'name'), false, 'haveAtt', JSON.stringify([]));
assert(haveAttr(NaN, 'name'), false, 'haveAtt', NaN);
assert(haveAttr(1, 'name'), false, 'haveAtt', 1);
assert(haveAttr(1.1, 'name'), false, 'haveAtt', 1.1);
console.log('\n');

assert(isArray(null), false, 'isArray', null);
assert(isArray(undefined), false, 'isArray', undefined);
assert(isArray({}), false, 'isArray', JSON.stringify({}));
assert(isArray({wrong: true}), false, 'isArray', JSON.stringify({wrong: true}));
assert(isArray({Name: true}), false, 'isArray', JSON.stringify({Name: true}));
assert(isArray({name: undefined}), false, 'isArray', JSON.stringify({name: undefined}) + ' att have undefined value...so only showing {}');
assert(isArray({name: false}), false, 'isArray', JSON.stringify({name: false}));
assert(isArray({name: null}), false, 'isArray', JSON.stringify({name: null}));
assert(isArray(new Date()), false, 'isArray', JSON.stringify(new Date()));
assert(isArray([]), true, 'isArray', JSON.stringify([]));
assert(isArray(NaN), false, 'isArray', NaN);
assert(isArray(1), false, 'isArray', 1);
assert(isArray(1.1), false, 'isArray', 1.1);
console.log('\n');

assert(isObject(null), false, 'isObject', null);
assert(isObject(undefined), false, 'isObject', undefined);
assert(isObject({}), true, 'isObject', JSON.stringify({}));
assert(isObject({wrong: true}), true, 'isObject', JSON.stringify({wrong: true}));
assert(isObject({Name: true}), true, 'isObject', JSON.stringify({Name: true}));
assert(isObject({name: undefined}), true, 'isObject', JSON.stringify({name: undefined}) + ' att have undefined value...so only showing {}');
assert(isObject({name: false}), true, 'isObject', JSON.stringify({name: false}));
assert(isObject({name: null}), true, 'isObject', JSON.stringify({name: null}));
assert(isObject(new Date()), false, 'isObject', JSON.stringify(new Date()));
assert(isObject([]), false, 'isObject', JSON.stringify([]));
assert(isObject(NaN), false, 'isObject', NaN);
assert(isObject(1), false, 'isObject', 1);
assert(isObject(1.1), false, 'isObject', 1.1);

console.log('\n');


assert(isDate(null), false, 'isDate', null);
assert(isDate(undefined), false, 'isDate', undefined);
assert(isDate({}), false, 'isDate', JSON.stringify({}));
assert(isDate({wrong: true}), false, 'isDate', JSON.stringify({wrong: true}));
assert(isDate({Name: true}), false, 'isDate', JSON.stringify({Name: true}));
assert(isDate({name: undefined}), false, 'isDate', JSON.stringify({name: undefined}) + ' att have undefined value...so only showing {}');
assert(isDate({name: false}), false, 'isDate', JSON.stringify({name: false}));
assert(isDate({name: null}), false, 'isDate', JSON.stringify({name: null}));
assert(isDate(new Date()), true, 'isDate', JSON.stringify(new Date()));
assert(isDate([]), false, 'isDate', JSON.stringify([]));
assert(isDate(NaN), false, 'isDate', NaN);
assert(isDate(1), false, 'isDate', 1);
assert(isDate(1.1), false, 'isDate', 1.1);