feat(preconditions): add checking accept-ranges header before evaluate if-ranges header

Author: TomokiMiyauci

_tools/meta.ts

@@ -86,10 +86,6 @@ export const makeOptions = (version: string): BuildOptions => ({
       name: "@httpland/http-utils",
       version: "1.0.0-beta.14",
     },
-    "https://deno.land/x/[email protected]/mod.ts": {
-      name: "@httpland/etag-parser",
-      version: "1.0.0",
-    },
     "https://deno.land/x/[email protected]/mod.ts": {
       name: "@miyauci/result",
       version: "1.0.0",
@@ -98,5 +94,9 @@ export const makeOptions = (version: string): BuildOptions => ({
       name: "@httpland/range-request-middleware",
       version: "1.0.0",
     },
+    "https://deno.land/x/[email protected]/mod.ts": {
+      name: "@httpland/accept-ranges-parser",
+      version: "1.0.0",
+    },
   },
 });

deno.lock

@@ -47,6 +47,10 @@ export {
   type RangesSpecifier,
 } from "https://deno.land/x/[email protected]/mod.ts";
 export { default as parseHttpDate } from "https://esm.sh/[email protected]";
+export {
+  parseAcceptRanges,
+  type Token,
+} from "https://deno.land/x/[email protected]/mod.ts";
 
 export function not<T extends readonly unknown[]>(
   fn: (...args: T) => boolean,

deps.ts

@@ -6,6 +6,7 @@ import {
   ConditionalHeader,
   isErr,
   isNull,
+  isString,
   Method,
   type Range,
   RangeHeader,
@@ -15,6 +16,11 @@ import {
 } from "../deps.ts";
 import { Precondition } from "../types.ts";
 import { ifRange } from "./utils.ts";
+import { hasToken } from "../utils.ts";
+
+const enum RangeUnit {
+  None = "none",
+}
 
 export function evaluateIfRange(
   request: Request,
@@ -29,15 +35,17 @@ export function evaluateIfRange(
     !request.headers.has(RangeHeader.Range)
   ) return;
 
+  const acceptRanges = response.headers.get(RangeHeader.AcceptRanges);
+
   /** An origin server MUST ignore an If-Range header field received in a request for a target resource that does not support Range requests. */
-  // TODO:(miyauci) Check accept-ranges is none or not.
+  if (isString(acceptRanges) && hasToken(acceptRanges, RangeUnit.None)) return;
 
-  const v = {
+  const headers = {
     etag: response.headers.get(RepresentationHeader.ETag),
     lastModified: response.headers.get(RepresentationHeader.LastModified),
   };
 
-  const result = unsafe(() => ifRange(ifRangeValue, v));
+  const result = unsafe(() => ifRange(ifRangeValue, headers));
 
   if (isErr(result)) return;
 

preconditions/if_range.ts

@@ -72,6 +72,25 @@ describe("evaluateIfRange", () => {
     });
   });
 
+  it("should return undefined if the response has accept-ranges and include none", () => {
+    assertEquals(
+      evaluateIfRange(
+        new Request("test:", {
+          headers: {
+            [ConditionalHeader.IfRange]: `""`,
+            [RangeHeader.Range]: "",
+          },
+        }),
+        new Response(null, {
+          headers: {
+            [RangeHeader.AcceptRanges]: "unknown, none",
+          },
+        }),
+      ),
+      undefined,
+    );
+  });
+
   it("should return false if the etag does not match strong", () => {
     const table: [Request, Response][] = [
       [

preconditions/if_range_test.ts

@@ -12,9 +12,11 @@ import {
   isSuccessfulStatus,
   Method,
   not,
+  parseAcceptRanges,
   RepresentationHeader,
   Status,
   SuccessfulStatus,
+  type Token,
 } from "./deps.ts";
 import type { Precondition } from "./types.ts";
 
@@ -111,3 +113,14 @@ export function withoutConditionHeaders(
 
   return newHeaders;
 }
+
+/** Whether the input has {@link Token} or not.
+ * If the input is invalid [`Accept-Ranges`](https://www.rfc-editor.org/rfc/rfc9110.html#section-14.3-2) then `false`.
+ */
+export function hasToken(input: string, token: Token): boolean {
+  try {
+    return parseAcceptRanges(input).includes(token);
+  } catch {
+    return false;
+  }
+}