feat(middleware): add range middleware factory

_dev_deps.ts

@@ -0,0 +1,18 @@
+export {
+  assert,
+  assertEquals,
+  assertThrows,
+} from "https://deno.land/std@0.178.0/testing/asserts.ts";
+export { describe, it } from "https://deno.land/std@0.178.0/testing/bdd.ts";
+export {
+  assertSpyCall,
+  assertSpyCalls,
+  spy,
+} from "https://deno.land/std@0.178.0/testing/mock.ts";
+export { Status } from "https://deno.land/std@0.178.0/http/http_status.ts";
+export { equalsResponse } from "https://deno.land/x/http_utils@1.0.0-beta.13/response.ts";
+export {
+  ConditionalHeader,
+  RangeHeader,
+  RepresentationHeader,
+} from "https://deno.land/x/http_utils@1.0.0-beta.13/header.ts";

deps.ts

@@ -0,0 +1,57 @@
+// Copyright 2023-latest the httpland authors. All rights reserved. MIT license.
+// This module is browser compatible.
+
+export { Status } from "https://deno.land/std@0.178.0/http/http_status.ts";
+export {
+  isNull,
+  isNumber,
+  isString,
+} from "https://deno.land/x/isx@1.0.0-beta.24/mod.ts";
+export { type Middleware } from "https://deno.land/x/http_middleware@1.0.0-beta.1/mod.ts";
+export {
+  ConditionalHeader,
+  RangeHeader,
+  RepresentationHeader,
+} from "https://deno.land/x/http_utils@1.0.0-beta.12/header.ts";
+export { Method } from "https://deno.land/x/http_utils@1.0.0-beta.12/method.ts";
+export { isErr, unsafe } from "https://deno.land/x/result_js@1.0.0/mod.ts";
+import {
+  RepresentationHeader,
+} from "https://deno.land/x/http_utils@1.0.0-beta.12/header.ts";
+export {
+  type IntRange,
+  isIntRange,
+  isOtherRange,
+  isSuffixRange,
+  type OtherRange,
+  parse,
+  type Range,
+  type RangeSpec,
+  type RangesSpecifier,
+  type SuffixRange,
+} from "https://deno.land/x/range_parser@1.0.0/mod.ts";
+export { concat } from "https://deno.land/std@0.178.0/bytes/concat.ts";
+export { toHashString } from "https://deno.land/std@0.178.0/crypto/to_hash_string.ts";
+
+/** Create headers with no representation header fields. */
+export class NoContentHeaders extends Headers {
+  constructor(init?: HeadersInit | undefined) {
+    super(init);
+
+    const allHeaders = [
+      RepresentationHeader.ContentEncoding,
+      RepresentationHeader.ContentLanguage,
+      RepresentationHeader.ContentLength,
+      RepresentationHeader.ContentLocation,
+      RepresentationHeader.ContentType,
+      RepresentationHeader.ETag,
+      RepresentationHeader.LastModified,
+    ];
+
+    allHeaders.forEach(this.delete.bind(this));
+  }
+}
+
+export function isNotEmpty<T>(input: readonly T[]): input is [T, ...T[]] {
+  return !!input.length;
+}

middleware.ts

@@ -0,0 +1,20 @@
+// deno-lint-ignore-file no-explicit-any
+
+import { type Middleware } from "./deps.ts";
+import { withContentRange } from "./transform.ts";
+import { BytesRange } from "./ranges/bytes.ts";
+import type { Range } from "./types.ts";
+
+interface Options {
+  readonly ranges?: readonly Range<any>[];
+}
+
+export function range(options?: Options): Middleware {
+  const ranges = options?.ranges ?? [new BytesRange() as Range<any>];
+
+  return async (request, next) => {
+    const response = await next(request);
+
+    return withContentRange(request, response, { ranges });
+  };
+}

middleware_test.ts

@@ -0,0 +1,81 @@
+import { range } from "./middleware.ts";
+import {
+  assert,
+  describe,
+  equalsResponse,
+  it,
+  RangeHeader,
+  RepresentationHeader,
+  Status,
+} from "./_dev_deps.ts";
+
+describe("range", () => {
+  it("should", async () => {
+    const middleware = range();
+    const rangeRequest = new Request("test:", {
+      headers: { range: "bytes=5-9" },
+    });
+    const response = await middleware(
+      rangeRequest,
+      () => new Response("abcdefghijklmnopqrstuvwxyz"),
+    );
+
+    assert(
+      await equalsResponse(
+        response,
+        new Response(`fghij`, {
+          status: Status.PartialContent,
+          headers: {
+            [RangeHeader.ContentRange]: `bytes 5-9/26`,
+          },
+        }),
+        true,
+      ),
+    );
+  });
+
+  it("should", async () => {
+    const middleware = range();
+    const rangeRequest = new Request("test:", {
+      headers: { range: "bytes=5-9, 20-, -5" },
+    });
+    const response = await middleware(
+      rangeRequest,
+      () => new Response("abcdefghijklmnopqrstuvwxyz"),
+    );
+
+    const boundary = `32d10c7b8cf96570ca04ce37f2a19d84240d3a89`;
+
+    assert(
+      await equalsResponse(
+        response,
+        new Response(
+          `--${boundary}
+Content-Type: text/plain;charset=UTF-8
+Content-Range: 5-9/26
+
+fghij
+--${boundary}
+Content-Type: text/plain;charset=UTF-8
+Content-Range: 20-25/26
+
+uvwxyz
+--${boundary}
+Content-Type: text/plain;charset=UTF-8
+Content-Range: 21-25/26
+
+vwxyz
+--${boundary}--`,
+          {
+            status: Status.PartialContent,
+            headers: {
+              [RepresentationHeader.ContentType]:
+                `multipart/byteranges; boundary=${boundary}`,
+            },
+          },
+        ),
+        true,
+      ),
+    );
+  });
+});