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@emmanuelnk
Created May 13, 2020 08:07
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Clean js object by recursive removal of undefined, null, NaN and empty strings
// A SO answer to https://stackoverflow.com/questions/286141/remove-blank-attributes-from-an-object-in-javascript
// based off the recursive cleanEmpty function by @chickens.
// This one can also handle Date objects correctly
// and has a defaults list for values you want stripped.
const cleanEmpty = function(obj, defaults = [undefined, null, NaN, '']) {
if (defaults.includes(obj)) return
if (Array.isArray(obj))
return obj
.map(v => v && typeof v === 'object' ? cleanEmpty(v, defaults) : v)
.filter(v => !defaults.includes(v))
return Object.entries(obj).length
? Object.entries(obj)
.map(([k, v]) => ([k, v && typeof v === 'object' ? cleanEmpty(v, defaults) : v]))
.reduce((a, [k, v]) => (defaults.includes(v) ? a : { ...a, [k]: v}), {})
: obj
}
// testing
console.log('testing: undefined \n', cleanEmpty(undefined))
console.log('testing: null \n',cleanEmpty(null))
console.log('testing: NaN \n',cleanEmpty(NaN))
console.log('testing: empty string \n',cleanEmpty(''))
console.log('testing: empty array \n',cleanEmpty([]))
console.log('testing: date object \n',cleanEmpty(new Date(1589339052 * 1000)))
console.log('testing: nested empty arr \n',cleanEmpty({ 1: { 2 :null, 3: [] }}))
console.log('testing: comprehensive obj \n', cleanEmpty({
a: 5,
b: 0,
c: undefined,
d: {
e: null,
f: [{
a: undefined,
b: new Date(),
c: ''
}]
},
g: NaN,
h: null
}))
console.log('testing: different defaults \n', cleanEmpty({
a: 5,
b: 0,
c: undefined,
d: {
e: null,
f: [{
a: undefined,
b: '',
c: new Date()
}]
},
g: [0, 1, 2, 3, 4],
h: '',
}, [undefined, null]))
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