fix: make filterBy and mapBy generic, allow any function for pick

ember-composable-helpers/src/helpers/filter-by.ts

@@ -5,7 +5,11 @@ import { get } from '@ember/object';
 import isEqual from '../utils/is-equal.ts';
 import asArray from '../utils/as-array.ts';
 
-export function filterBy<T>([byPath, value, array]: [string, T | T[] | undefined, T[]]) {
+export function filterBy<T extends object, K extends keyof T>([
+  byPath,
+  value,
+  array,
+]: [K, T[K] | T[] | undefined, T[]]) {
 
   let isPresent = true;
   if (!isEmberArray(array) && isEmberArray(value)) {

ember-composable-helpers/src/helpers/map-by.ts

@@ -3,12 +3,12 @@ import { get } from '@ember/object';
 import { isEmpty } from '@ember/utils';
 import asArray from '../utils/as-array.ts';
 
-export function mapBy<T>([byPath, array]: [keyof T, T[]]) {
+export function mapBy<T extends object>([byPath, array]: [keyof T, T[]]) {
   if (isEmpty(byPath)) {
     return [];
   }
 
-  return asArray(array).map(item => get(item as object, byPath as string));
+  return asArray(array).map(item => get(item, byPath));
 }
 
 export default helper(mapBy);

ember-composable-helpers/src/helpers/pick.ts

@@ -1,7 +1,7 @@
 import { helper } from '@ember/component/helper';
 import { get } from '@ember/object';
 
-export function pick([path, action]: [string, (value: unknown) => void]) {
+export function pick([path, action]: [string, (...args: any[]) => void]) {
   return function(event: Event) {
     let value = get(event, path);