ParserBase

The shared base for the input parsers that turn flat key/value pairs into nested objects.

URLParamsParser, SearchParamsParser and FormDataParser all face the same problem: a source that only carries strings paired with strings, where structure has to be recovered from the key itself and types from the value. ParserBase supplies both halves — ParserBase.parseKey for the bracket notation and ParserBase.tryParseJSON for value coercion — so the three agree on what user[roles][0]=admin means regardless of which surface it arrived on.

Subclass it to add a parser of your own, then register it through setParsersRegistry.

ParserBase

class

abstract class ParserBase<T>implements ParserBaseInterface<T>

Base class for the input parsers.

It provides the key and value handling; each subclass supplies ParserBase.parse for its own source and does the writing, since how repeated keys collect differs between a query string and a form.

Type parameters

• T — The input the parser accepts.

ParserBase.parse()

abstract parse(input: T): Record<string, unknown>;

Converts the input into a nested object. Implemented per source.

Parameters

• input — The source to parse.

Returns — The parsed object.

ParserBase.newContainer()

protected newContainer(current: unknown): Record<string | number, unknown>

Narrows a value to an indexable container so a path segment can be written into it.

Purely a readability helper for the traversal loops — the value is used as-is, nothing is constructed.

Parameters

• current — The level currently being written into.

Returns — The same value, typed for index access.

ParserBase.parseKey()

protected parseKey(key: string):(string | number)[]

Splits a key into the path it describes.

Dot and bracket notation are treated as equivalent, so a[0].b[1][c] and a.0.b.1.c both yield ["a", 0, "b", 1, "c"]. A purely numeric segment becomes a number, which is how the subclasses know to create an array rather than an object at that level — subject to ARRAY_INDEX_LIMIT, above which the segment stays a string key.

Parameters

• key — The raw field name.

Returns — The path segments: numbers for array indices, strings for object keys.

ParserBase.tryParseJSON()

protected tryParseJSON(value: string): unknown

Coerces a raw string value into whatever it represents.

Since every value from these sources arrives as a string, "42", "true" and "null" are decoded to their JSON equivalents. Anything that is not valid JSON — ordinary text, most of the time — is returned unchanged rather than treated as an error.

Parameters

• value — The raw string value.

Returns — The decoded value, or the original string.