Type Alias DeepMergeStrict<Left, Right>

DeepMergeStrict: Left extends (infer U)[]
    ? DeepMergeStrict<U, Right>[]
    : Left extends ReadonlyArray<infer U>
        ? ReadonlyArray<DeepMergeStrict<U, Right>>
        : Left extends object
            ? Right extends object
                ? {
                    [K in keyof Left]: K extends keyof Right
                        ? DeepMergeStrict<Left[K], Right[K]>
                        : DeepMergeStrict<Left[K], Right>
                } & { [K in Exclude<keyof Right, keyof Left>]: Right[K] }
                : Left
            : Left

Strict deep merge of two object types.

Type Parameters

Left
Base object type
Right
Overriding object type

Since

1.1.0

Remarks

Similar to DeepMerge but preserves array types from the left-hand side by injecting right-hand properties into array element types.

Example

type A = { a: { x: { foo: true } } };
type B = { a: { x: { foo: number, bar: string } } };
type Merged = < A, B >;
// { a: { x: { foo: true, bar: string } } }