HTTP Range header field parser
npm install @httpland/range-parser






HTTP Range header field parser.
Compliant with
RFC 9110, 14.2 Range
Parses a string as HTTP Range header field and yield JavaScript Object.
The field naming conventions follow
RFC 9110, 14.2. Range.
``ts
import { parseRange } from "https://deno.land/x/range_parser@$VERSION/parse.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
const actual = parseRange("bytes=0-100, 200-, -300, test");
assertEquals(actual, {
rangeUnit: "bytes",
rangeSet: [
{ firstPos: 0, lastPos: 100 },
{ firstPos: 200, lastPos: undefined },
{ suffixLength: 300 },
"test",
],
});
`
rangeSet is a list of one or more , and according to the definition of .
It has the following data structure:
`ts`
interface IntRange {
firstPos: number;
lastPos: number | undefined;
}
interface SuffixRange {
suffixLength: number;
}
type OtherRange = string;
The parser strictly adheres to the ABNF syntax. It also checks semantics.
Specifically, the parser guarantees the following:
- The or number is a non-negative integer
- and are syntactically valid strings
- , is equal to or greater than .
Throws SyntaxError if it detects invalid syntax.
`ts
import { parseRange } from "https://deno.land/x/range_parser@$VERSION/parse.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";
assertThrows(() => parseRange("
`
The following cases are semantic error:
- , less than .
see
RFC 9110, 14.1.1. Range Specifiers
In this case, it throws a RangeError.
`ts
import { parseRange } from "https://deno.land/x/range_parser@$VERSION/parse.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";
assertThrows(() => parseRange("bytes=1-0"));
`
Serializes Range into string.
`ts
import { stringifyRange } from "https://deno.land/x/range_parser@$VERSION/stringify.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
assertEquals(
stringifyRange({
rangeUnit: "bytes",
rangeSet: [{ firstPos: 0, lastPos: 100 }, { suffixLength: 200 }],
}),
"bytes=0-100, -200",
);
`
Throws TypeError if Range contains errors.
For error definitions, see the Parsing specification.
`ts
import { stringifyRange } from "https://deno.land/x/range_parser@$VERSION/stringify.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";
assertThrows(() =>
stringifyRange({
rangeUnit: "bytes",
rangeSet: [{ firstPos: NaN, lastPos: undefined }],
})
);
`
We provide some utilities.
Whether the RangeSpec is IntRange or not.
`ts
import {
type IntRange,
isIntRange,
type OtherRange,
type SuffixRange,
} from "https://deno.land/x/range_parser@$VERSION/mod.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";
declare const intRange: IntRange;
declare const suffixRange: SuffixRange;
declare const otherRange: OtherRange;
assert(isIntRange(intRange));
assert(!isIntRange(suffixRange));
assert(!isIntRange(otherRange));
`
Whether the RangeSpec is SuffixRange or not.
`ts
import {
type IntRange,
isSuffixRange,
type OtherRange,
type SuffixRange,
} from "https://deno.land/x/range_parser@$VERSION/mod.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";
declare const intRange: IntRange;
declare const suffixRange: SuffixRange;
declare const otherRange: OtherRange;
assert(isSuffixRange(suffixRange));
assert(!isSuffixRange(intRange));
assert(!isSuffixRange(otherRange));
`
Whether the RangeSpec is OtherRange or not.
`ts
import {
type IntRange,
isOtherRange,
type OtherRange,
type SuffixRange,
} from "https://deno.land/x/range_parser@$VERSION/mod.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";
declare const intRange: IntRange;
declare const suffixRange: SuffixRange;
declare const otherRange: OtherRange;
assert(isOtherRange(otherRange));
assert(!isOtherRange(intRange));
assert(!isOtherRange(suffixRange));
`
Whether the input is HTTP Range header field format or not.
`ts
import { isRangeFormat } from "https://deno.land/x/range_parser@$VERSION/mod.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";
assert(isRangeFormat("bytes=0-100, 200-, -500"));
assert(!isRangeFormat("
``
Copyright © 2023-present httpland.
Released under the MIT license