const my_obj = {
a: 1,
b: { c: 2 },
d: { e: { f: 3 }, g: 4 },
h: { i: [{ j: 5 }, { k: 6 }] },
l: { m: ((arg: string) => "hello") },
n: new URL("https://example.com"),
o: new Map<string, number>([["a", 1], ["b", 2]]),
} as const
type DeeplyPartial_my_obj = DeepPartial<typeof my_obj>
type ManuallyConstructed_DeeplyPartial_my_obj = {
a?: 1,
b?: { c?: 2 },
d?: { e?: { f?: 3 }, g?: 4 },
h?: { i?: readonly [_0?: { j?: 5 } | undefined, _1?: { k?: 6 } | undefined] },
l?: { m?: ((arg: string) => string) },
n?: URL,
o?: Map<string, number>,
}
type BothTypesAreEqual_1 = DeeplyPartial_my_obj extends ManuallyConstructed_DeeplyPartial_my_obj ? true : false
type BothTypesAreEqual_2 = ManuallyConstructed_DeeplyPartial_my_obj extends DeeplyPartial_my_obj ? true : false
const temp: true = true
temp satisfies BothTypesAreEqual_1
temp satisfies BothTypesAreEqual_2
turn all fields of an object
Tto optional, deeply.we exclude many built-in types and classes so that they are not turned into partial types. here is the full list of built-in types and classes (aside from primitives) that are not turned into partial objects:
Function | Array<any> | Set<any> | Map<any, any> | WeakSet<any> | WeakMap<any, any> | TypedArray | URL | String | BigInt | Number | Boolean | Symbol