exhaustive

exhaustive() unwraps a PatternResult and checks that all cases have been covered. It is used both with the builder match(...).exhaustive() and in a direct call on any PatternResult. If a pattern is missing, an InvalidExhaustivePatternError is thrown at call time.

Interactive example

Syntax

function exhaustive<
	const GenericInput extends unknown, 
	GenericResult extends PatternResult<GenericInput>
>(result: GenericResult): Unwrap<GenericResult>;

Parameters

• result: a PatternResult returned by a match builder (after .with()/.when()).

Return value

The value actually contained in the PatternResult, with the type refined. If the initial union has not been fully covered, the call fails and shows you the remaining value.

Best practices

• On the builder: match(...).with(...).exhaustive() ensures each branch is covered before returning the final value.
• In direct call: pass any PatternResult to unwrap it and force the exhaustiveness check.
• During development, let exhaustive point out missing cases rather than adding an overly broad otherwise.

See also

• match
• when
• otherwise