@httpland/range-parser
v1.2.0
Published
HTTP Range header field parser
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range-parser
HTTP Range
header field parser.
Compliant with RFC 9110, 14.2 Range
Deserialization
Parses a string as HTTP Range
header field and yield JavaScript Object.
The field naming conventions follow RFC 9110, 14.2. Range.
import { parseRange } from "https://deno.land/x/range_parser@$VERSION/parse.ts";
import { assertEquals } from "https://deno.land/std/testing/asserts.ts";
const actual = parseRange("bytes=0-100, 200-, -300, test");
assertEquals(actual, {
rangeUnit: "bytes",
rangeSet: [
{ firstPos: 0, lastPos: 100 },
{ firstPos: 200, lastPos: undefined },
{ suffixLength: 300 },
"test",
],
});
rangeSet
is a list of one or more <int-range>
, <suffix-range>
and
<other-range>
according to the definition of <range-spec>
.
It has the following data structure:
interface IntRange {
firstPos: number;
lastPos: number | undefined;
}
interface SuffixRange {
suffixLength: number;
}
type OtherRange = string;
Parsing specification
The parser strictly adheres to the ABNF syntax. It also checks semantics.
Specifically, the parser guarantees the following:
- The
<int-range>
or<suffix-range>
number is a non-negative integer <range-unit>
and<other-range>
are syntactically valid strings<int-range>
,<first-pos>
is equal to or greater than<last-pos>
.
Syntax error
Throws SyntaxError
if it detects invalid syntax.
import { parseRange } from "https://deno.land/x/range_parser@$VERSION/parse.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";
assertThrows(() => parseRange("<invalid:input>"));
Semantic error
The following cases are semantic error:
<int-range>
,<last-pos>
less than<first-pos>
.
see RFC 9110, 14.1.1. Range Specifiers
In this case, it throws a RangeError
.
import { parseRange } from "https://deno.land/x/range_parser@$VERSION/parse.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";
assertThrows(() => parseRange("bytes=1-0"));
Serialization
Serializes Range
into string.
import { stringifyRange } from "https://deno.land/x/range_parser@$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",
);
Throwing error
Throws TypeError
if Range
contains errors.
For error definitions, see the Parsing specification.
import { stringifyRange } from "https://deno.land/x/range_parser@$VERSION/stringify.ts";
import { assertThrows } from "https://deno.land/std/testing/asserts.ts";
assertThrows(() =>
stringifyRange({
rangeUnit: "bytes",
rangeSet: [{ firstPos: NaN, lastPos: undefined }],
})
);
Utility
We provide some utilities.
isIntRange
Whether the RangeSpec
is IntRange
or not.
import {
type IntRange,
isIntRange,
type OtherRange,
type SuffixRange,
} from "https://deno.land/x/range_parser@$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));
isSuffixRange
Whether the RangeSpec
is SuffixRange
or not.
import {
type IntRange,
isSuffixRange,
type OtherRange,
type SuffixRange,
} from "https://deno.land/x/range_parser@$VERSION/mod.ts";
import { assert } from "https://deno.land/std/testing/asserts.ts";
declare const intRange: IntRange;
declare const suffixRange: SuffixRange;
declare const otherRange: OtherRange;
assert(isSuffixRange(suffixRange));
assert(!isSuffixRange(intRange));
assert(!isSuffixRange(otherRange));
isOtherRange
Whether the RangeSpec
is OtherRange
or not.
import {
type IntRange,
isOtherRange,
type OtherRange,
type SuffixRange,
} from "https://deno.land/x/range_parser@$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));
isRangeFormat
Whether the input is HTTP Range
header field format or not.
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("<invalid>"));
License
Copyright © 2023-present httpland.
Released under the MIT license