cloudflare/cloudflare-typescript
Publicmirrored from https://github.com/cloudflare/cloudflare-typescriptAvailable
src/internal/headers.ts
97lines · modecode
| 1 | // File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details. |
| 2 | |
| 3 | import { isReadonlyArray } from './utils/values'; |
| 4 | |
| 5 | type HeaderValue = string | undefined | null; |
| 6 | export type HeadersLike = |
| 7 | | Headers |
| 8 | | readonly HeaderValue[][] |
| 9 | | Record<string, HeaderValue | readonly HeaderValue[]> |
| 10 | | undefined |
| 11 | | null |
| 12 | | NullableHeaders; |
| 13 | |
| 14 | const brand_privateNullableHeaders = /* @__PURE__ */ Symbol('brand.privateNullableHeaders'); |
| 15 | |
| 16 | /** |
| 17 | * @internal |
| 18 | * Users can pass explicit nulls to unset default headers. When we parse them |
| 19 | * into a standard headers type we need to preserve that information. |
| 20 | */ |
| 21 | export type NullableHeaders = { |
| 22 | /** Brand check, prevent users from creating a NullableHeaders. */ |
| 23 | [brand_privateNullableHeaders]: true; |
| 24 | /** Parsed headers. */ |
| 25 | values: Headers; |
| 26 | /** Set of lowercase header names explicitly set to null. */ |
| 27 | nulls: Set<string>; |
| 28 | }; |
| 29 | |
| 30 | function* iterateHeaders(headers: HeadersLike): IterableIterator<readonly [string, string | null]> { |
| 31 | if (!headers) return; |
| 32 | |
| 33 | if (brand_privateNullableHeaders in headers) { |
| 34 | const { values, nulls } = headers; |
| 35 | yield* values.entries(); |
| 36 | for (const name of nulls) { |
| 37 | yield [name, null]; |
| 38 | } |
| 39 | return; |
| 40 | } |
| 41 | |
| 42 | let shouldClear = false; |
| 43 | let iter: Iterable<readonly (HeaderValue | readonly HeaderValue[])[]>; |
| 44 | if (headers instanceof Headers) { |
| 45 | iter = headers.entries(); |
| 46 | } else if (isReadonlyArray(headers)) { |
| 47 | iter = headers; |
| 48 | } else { |
| 49 | shouldClear = true; |
| 50 | iter = Object.entries(headers ?? {}); |
| 51 | } |
| 52 | for (let row of iter) { |
| 53 | const name = row[0]; |
| 54 | if (typeof name !== 'string') throw new TypeError('expected header name to be a string'); |
| 55 | const values = isReadonlyArray(row[1]) ? row[1] : [row[1]]; |
| 56 | let didClear = false; |
| 57 | for (const value of values) { |
| 58 | if (value === undefined) continue; |
| 59 | |
| 60 | // Objects keys always overwrite older headers, they never append. |
| 61 | // Yield a null to clear the header before adding the new values. |
| 62 | if (shouldClear && !didClear) { |
| 63 | didClear = true; |
| 64 | yield [name, null]; |
| 65 | } |
| 66 | yield [name, value]; |
| 67 | } |
| 68 | } |
| 69 | } |
| 70 | |
| 71 | export const buildHeaders = (newHeaders: HeadersLike[]): NullableHeaders => { |
| 72 | const targetHeaders = new Headers(); |
| 73 | const nullHeaders = new Set<string>(); |
| 74 | for (const headers of newHeaders) { |
| 75 | const seenHeaders = new Set<string>(); |
| 76 | for (const [name, value] of iterateHeaders(headers)) { |
| 77 | const lowerName = name.toLowerCase(); |
| 78 | if (!seenHeaders.has(lowerName)) { |
| 79 | targetHeaders.delete(name); |
| 80 | seenHeaders.add(lowerName); |
| 81 | } |
| 82 | if (value === null) { |
| 83 | targetHeaders.delete(name); |
| 84 | nullHeaders.add(lowerName); |
| 85 | } else { |
| 86 | targetHeaders.append(name, value); |
| 87 | nullHeaders.delete(lowerName); |
| 88 | } |
| 89 | } |
| 90 | } |
| 91 | return { [brand_privateNullableHeaders]: true, values: targetHeaders, nulls: nullHeaders }; |
| 92 | }; |
| 93 | |
| 94 | export const isEmptyHeaders = (headers: HeadersLike) => { |
| 95 | for (const _ of iterateHeaders(headers)) return false; |
| 96 | return true; |
| 97 | }; |
| 98 | |