`strip-undefined`

Purpose

stripUndefined is a route-layer adapter that bridges Zod's optional() output (T | undefined) with the exactOptionalPropertyTypes: true repository input types declared in @suaveplan/campaigns and the local CampaignSuppressionStore. When a route handler validates a request body through a Zod schema, optional fields surface as either the declared type or undefined; passing the parsed object straight to the repository fails the exactOptional check at compile time. This helper produces a shallow clone with every undefined-valued key removed so the downstream type narrows.

The helper is intentionally minimal — no recursion, no null handling, no key-name filtering — because every concrete usage in the routes layer passes a Zod-parsed object whose nesting has already been normalised. Recursion would obscure the cost model and tempt callers to use it as a deep-clean utility, which is out of scope.

Features

Shallow-only filter; nested objects are forwarded by reference.
null values are preserved (only === undefined triggers removal).
Returns a fresh object reference every call (never mutates input).
Generic-typed return narrows T[K] to Exclude<T[K], undefined>.

Usage: Basic

import { stripUndefined } from "@suaveplan/api-plugin-campaigns";

const body = { name: "x", templateId: undefined } as const;
const clean = stripUndefined(body);
// clean: { name: "x" } — `templateId` removed.

Usage: Advanced

import { stripUndefined } from "@suaveplan/api-plugin-campaigns";

const parsed = CreateCampaignSchema.parse(input);
await repo.create({
    id: idGen(),
    tenantId,
    ...stripUndefined(parsed),
    status: "draft",
    stats: EMPTY_STATS,
    createdAt: now,
    updatedAt: now,
});

API Reference

stripUndefined<T extends Record<string, unknown>>(input: T): { [K in keyof T]: Exclude<T[K], undefined> } — shallow copy with undefined-valued keys removed.

Implementation Notes

The implementation iterates Object.entries(input) once and writes into a fresh Record<string, unknown> accumulator. The output is then cast to the narrowed mapped type — a single assertion confined to the return statement. The accumulator is not pre-sized because the helper is hot-path-cheap (single object scan) and JavaScript engines do not benefit from new Object() capacity hints. The forbidden Object.assign path (which would forward undefined properties when iterating Object.keys) is intentionally avoided.

2.5 KiB Raw Blame History

strip-undefined