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Diffstat (limited to 'includes/external/school/node_modules/graphql/jsutils/keyValMap.js.flow')
-rw-r--r-- | includes/external/school/node_modules/graphql/jsutils/keyValMap.js.flow | 30 |
1 files changed, 30 insertions, 0 deletions
diff --git a/includes/external/school/node_modules/graphql/jsutils/keyValMap.js.flow b/includes/external/school/node_modules/graphql/jsutils/keyValMap.js.flow new file mode 100644 index 0000000..d3aa602 --- /dev/null +++ b/includes/external/school/node_modules/graphql/jsutils/keyValMap.js.flow @@ -0,0 +1,30 @@ +// @flow strict +import type { ObjMap } from './ObjMap'; + +/** + * Creates a keyed JS object from an array, given a function to produce the keys + * and a function to produce the values from each item in the array. + * + * const phoneBook = [ + * { name: 'Jon', num: '555-1234' }, + * { name: 'Jenny', num: '867-5309' } + * ] + * + * // { Jon: '555-1234', Jenny: '867-5309' } + * const phonesByName = keyValMap( + * phoneBook, + * entry => entry.name, + * entry => entry.num + * ) + * + */ +export default function keyValMap<T, V>( + list: $ReadOnlyArray<T>, + keyFn: (item: T) => string, + valFn: (item: T) => V, +): ObjMap<V> { + return list.reduce((map, item) => { + map[keyFn(item)] = valFn(item); + return map; + }, Object.create(null)); +} |