ES5/ES6/ES2017/ES2019 omit & pick

ES5-ES6-ES2017-ES2019 omit & pick

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omit-es2015.js

Object.keys(obj)
.filter((key) => ['blacklisted', 'keys'].indexOf(key) < 0)
.reduce((newObj, key) => Object.assign(newObj, { [key]: obj[key] }), {})

omit-es2017.js

Object.entries(obj)
.filter(([key]) => !['blacklisted', 'keys'].includes(key))
.reduce((obj, [key, val]) => Object.assign(obj, { [key]: val }), {});

omit-es2019.js

Object.fromEntries(
  Object.entries(obj)
  .filter(([key]) => !['blacklisted', 'keys'].includes(key))
);

pick-es2015.js

Object.keys(obj)
.filter((key) => ['whitelisted', 'keys'].indexOf(key) >= 0)
.reduce((newObj, key) => Object.assign(newObj, { [key]: obj[key] }), {})

pick-es2017.js

Object.entries(obj)
.filter(([key]) => ['whitelisted', 'keys'].includes(key))
.reduce((obj, [key, val]) => Object.assign(obj, { [key]: val }), {});

pick-es2019.js

Object.fromEntries(
  Object.entries(obj)
  .filter(([key]) => ['whitelisted', 'keys'].includes(key))
);

Object.assign({}, ...['whitelisted', 'keys'].map(key => ({ [key]: obj[key] })))

This will not work if obj is an empty object.

Typesafe omit:

export function omit<T extends object, K extends keyof T>(obj: T, paths: K[]): Omit<T, K> {
  return {
    ...paths.reduce((mem, key) => ((k: K, { [k]: ignored, ...rest }) => rest)(key, mem), obj as object),
  } as Omit<T, K>;
}

Another solution to pick

const pick = <T extends object, K extends keyof T>(
    whitelisted: K[],
    target: T,
    defaultValue?: any
) =>
    Object.fromEntries(
        whitelisted.map((key) =>
            [ key, key in target ? target[key] : defaultValue ]
        )
    );