wrapMatcher function Null safety
- Object? valueOrMatcher
Takes an argument and returns an equivalent Matcher.
If the argument is already a matcher this does nothing, else if the argument is a function, it generates a predicate function matcher, else it generates an equals matcher.
Implementation
Matcher wrapMatcher(Object? valueOrMatcher) {
if (valueOrMatcher is Matcher) {
return valueOrMatcher;
} else if (valueOrMatcher is bool Function(Object?)) {
// already a predicate that can handle anything
return predicate(valueOrMatcher);
} else if (valueOrMatcher is bool Function(Never)) {
// unary predicate, but expects a specific type
// so wrap it.
// ignore: unnecessary_lambdas
return predicate((a) => (valueOrMatcher as dynamic)(a));
} else {
return equals(valueOrMatcher);
}
}