@httpland/etag-parser

etag-parser

HTTP ETag header field parser.

Compliant with RFC 9110, 8.8.3. ETag.

Deserialization

Parses string into ETag.

import { parseETag } from "https://deno.land/x/etag_parser@$VERSION/parse.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(parseETag(`W/"123456789"`), { tag: "123456789", weak: true });
assertEquals(parseETag(`"123456789"`), { tag: "123456789", weak: false });

Throwing error

Throws SyntaxError if the input is invalid <entity-tag>.

import { parseETag } from "https://deno.land/x/etag_parser@$VERSION/parse.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";

assertThrows(() => parseETag("<invalid>"));

Serialization

Serialize ETag into string.

import { stringifyETag } from "https://deno.land/x/etag_parser@$VERSION/stringify.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";

assertEquals(stringifyETag({ weak: true, tag: "123456789" }), `W/"123456789"`);
assertEquals(stringifyETag({ weak: false, tag: "123456789" }), `"123456789"`);

Throwing error

Throws TypeError if ETag contains invalid value.

import { stringifyETag } from "https://deno.land/x/etag_parser@$VERSION/stringify.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";

assertThrows(() => stringifyETag({ tag: "aあ亜", weak: true }));

ETag

ETag is a structured object for ETag header.

Name	Type	Description
tag	string	Representation of <etagc>.
weak	boolean	Whether this is weak validator or not.

Utilities

Utility functions are provided.

compareWeak

Weak comparison. Two ETag are equivalent if ETag.tag match character-by-character, regardless of either or both being tagged as ETag.weak.

Compliant with RFC 9110, 8.8.3.2. Comparison.

import { compareWeak } from "https://deno.land/x/etag_parser@$VERSION/validate.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";

assert(
  compareWeak(
    { weak: true, tag: "123456789" },
    { weak: false, tag: "123456789" },
  ),
);

compareStrong

Strong comparison. Two ETag are equivalent if both are StrongETag and ETag.tag match character-by-character.

Compliant with RFC 9110, 8.8.3.2. Comparison.

import { compareWeak } from "https://deno.land/x/etag_parser@$VERSION/validate.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";

assert(
  compareWeak(
    { weak: false, tag: "123456789" },
    { weak: false, tag: "123456789" },
  ),
);

isWeakETag

Whether the ETag is WeakETag or not.

import { isWeakETag } from "https://deno.land/x/etag_parser@$VERSION/validate.ts";
import { assert, assertFalse } from "https://deno.land/std/testing/asserts.ts";

assert(isWeakETag({ weak: true, tag: "123456789" }));
assertFalse(isWeakETag({ weak: false, tag: "123456789" }));

isStrongETag

Whether the ETag is StrongETag or not.

import { isStrongETag } from "https://deno.land/x/etag_parser@$VERSION/validate.ts";
import { assert, assertFalse } from "https://deno.land/std/testing/asserts.ts";

assert(isStrongETag({ weak: false, tag: "123456789" }));
assertFalse(isStrongETag({ weak: true, tag: "123456789" }));

API

All APIs can be found in the deno doc.

License

Copyright © 2023-present httpland.

Released under the MIT license