matcher library Null safety

Support for specifying test expectations, such as for unit tests.

Classes

CustomMatcher

A useful utility class for implementing other matchers through inheritance. Derived classes should call the base constructor with a feature name and description, and an instance matcher, and should implement the featureValueOf abstract method.

Description

Matchers build up their error messages by appending to Description objects.

isInstanceOf<T>

DEPRECATED Use isA instead.

Matcher

The base class for all matchers.

StringDescription

The default implementation of Description. This should rarely need substitution, although conceivably it is a place where other languages could be supported.

TypeMatcher<T>

A Matcher subclass that supports validating the Type of the target object.

Constants

anything → const Matcher

A matcher that matches any value.

_IsAnything()

isArgumentError → const TypeMatcher<ArgumentError>

A matcher for ArgumentError.

TypeMatcher<ArgumentError>()

isCastError → const TypeMatcher<CastError>

A matcher for CastError.

@Deprecated('CastError has been deprecated in favor of TypeError. ' 'Use `isA<TypeError>()` or, if you need compatibility with older SDKs, ' 'use `isA<CastError>()` and ignore the deprecation.')

TypeMatcher<CastError>()

isConcurrentModificationError → const TypeMatcher<ConcurrentModificationError>

A matcher for ConcurrentModificationError.

TypeMatcher<ConcurrentModificationError>()

isCyclicInitializationError → const TypeMatcher<CyclicInitializationError>

A matcher for CyclicInitializationError.

TypeMatcher<CyclicInitializationError>()

isEmpty → const Matcher

Returns a matcher that matches the isEmpty property.

_Empty()

isException → const TypeMatcher<Exception>

A matcher for Exception.

TypeMatcher<Exception>()

isFalse → const Matcher

A matcher that matches anything except the Boolean value true.

_IsFalse()

isFormatException → const TypeMatcher<FormatException>

A matcher for FormatException.

TypeMatcher<FormatException>()

isList → const TypeMatcher<List>

A matcher for List.

TypeMatcher<List>()

isMap → const TypeMatcher<Map>

A matcher for Map.

TypeMatcher<Map>()

isNaN → const Matcher

A matcher that matches the numeric value NaN.

_IsNaN()

isNegative → const Matcher

A matcher which matches if the match argument is negative.

_OrderingMatcher(0, false, true, false, 'a negative value', false)

isNonNegative → const Matcher

A matcher which matches if the match argument is zero or positive.

_OrderingMatcher(0, true, false, true, 'a non-negative value', false)

isNonPositive → const Matcher

A matcher which matches if the match argument is zero or negative.

_OrderingMatcher(0, true, true, false, 'a non-positive value', false)

isNonZero → const Matcher

A matcher which matches if the match argument is non-zero.

_OrderingMatcher(0, false, true, true, 'a value not equal to')

isNoSuchMethodError → const TypeMatcher<NoSuchMethodError>

A matcher for NoSuchMethodError.

TypeMatcher<NoSuchMethodError>()

isNotEmpty → const Matcher

Returns a matcher that matches the isNotEmpty property.

_NotEmpty()

isNotNaN → const Matcher

A matcher that matches any non-NaN value.

_IsNotNaN()

isNotNull → const Matcher

A matcher that matches any non-null value.

_IsNotNull()

isNull → const Matcher

A matcher that matches any null value.

_IsNull()

isNullThrownError → const TypeMatcher<NullThrownError>

A matcher for NullThrownError.

TypeMatcher<NullThrownError>()

isPositive → const Matcher

A matcher which matches if the match argument is positive.

_OrderingMatcher(0, false, false, true, 'a positive value', false)

isRangeError → const TypeMatcher<RangeError>

A matcher for RangeError.

TypeMatcher<RangeError>()

isStateError → const TypeMatcher<StateError>

A matcher for StateError.

TypeMatcher<StateError>()

isTrue → const Matcher

A matcher that matches the Boolean value true.

_IsTrue()

isUnimplementedError → const TypeMatcher<UnimplementedError>

A matcher for UnimplementedError.

TypeMatcher<UnimplementedError>()

isUnsupportedError → const TypeMatcher<UnsupportedError>

A matcher for UnsupportedError.

TypeMatcher<UnsupportedError>()

isZero → const Matcher

A matcher which matches if the match argument is zero.

_OrderingMatcher(0, true, false, false, 'a value equal to')

returnsNormally → const Matcher

A matcher that matches a function call against no exception.

_ReturnsNormally()

Functions

addStateInfo(Map matchState, Map values) → void

Useful utility for nesting match states.

allOf(Object? arg0, [Object? arg1, Object? arg2, Object? arg3, Object? arg4, Object? arg5, Object? arg6]) → Matcher

This returns a matcher that matches if all of the matchers passed as arguments (up to 7) match.

anyElement(Object? valueOrMatcher) → Matcher

Returns a matcher which matches Iterables in which at least one element matches the given valueOrMatcher.

anyOf(Object? arg0, [Object? arg1, Object? arg2, Object? arg3, Object? arg4, Object? arg5, Object? arg6]) → Matcher

Matches if any of the given matchers evaluate to true.

closeTo(num value, num delta) → Matcher

Returns a matcher which matches if the match argument is within delta of some value.

collapseWhitespace(String string) → String

Utility function to collapse whitespace runs to single spaces and strip leading/trailing whitespace.

contains(Object? expected) → Matcher

Returns a matcher that matches if the match argument contains the expected value.

containsAll(Iterable expected) → Matcher

Matches Iterables which contain an element matching every value in expected in any order, and may contain additional values.

containsAllInOrder(Iterable expected) → Matcher

Matches Iterables which contain an element matching every value in expected in the same order, but may contain additional values interleaved throughout.

containsPair(Object? key, Object? valueOrMatcher) → Matcher

Returns a matcher which matches maps containing the key-value pair with key => valueOrMatcher.

containsValue(Object? value) → Matcher

Returns a matcher which matches maps containing the given value.

endsWith(String suffixString) → Matcher

Returns a matcher that matches if the match argument is a string and ends with suffixString.

equals(Object? expected, [int limit = 100]) → Matcher

Returns a matcher that matches if the value is structurally equal to expected.

equalsIgnoringCase(String value) → Matcher

Returns a matcher which matches if the match argument is a string and is equal to value when compared case-insensitively.

equalsIgnoringWhitespace(String value) → Matcher

Returns a matcher which matches if the match argument is a string and is equal to value, ignoring whitespace.

escape(String str) → String

Returns str with all whitespace characters represented as their escape sequences.

everyElement(Object? valueOrMatcher) → Matcher

Returns a matcher which matches Iterables in which all elements match the given valueOrMatcher.

greaterThan(Object value) → Matcher

Returns a matcher which matches if the match argument is greater than the given value.

greaterThanOrEqualTo(Object value) → Matcher

Returns a matcher which matches if the match argument is greater than or equal to the given value.

hasLength(Object? matcher) → Matcher

Returns a matcher that matches if an object has a length property that matches matcher.

inClosedOpenRange(num low, num high) → Matcher

Returns a matcher which matches if the match argument is greater than or equal to a low and less than high.

inExclusiveRange(num low, num high) → Matcher

Returns a matcher which matches if the match argument is greater than low and less than high.

inInclusiveRange(num low, num high) → Matcher

Returns a matcher which matches if the match argument is greater than or equal to low and less than or equal to high.

inOpenClosedRange(num low, num high) → Matcher

Returns a matcher which matches if the match argument is greater than low and less than or equal to high.

isA<T>() → TypeMatcher<T>

Returns a matcher that matches objects with type T.

isIn(Object? expected) → Matcher

Returns a matcher that matches if the match argument is in the expected value. This is the converse of contains.

isNot(Object? valueOrMatcher) → Matcher

Returns a matcher that inverts valueOrMatcher to its logical negation.

lessThan(Object value) → Matcher

Returns a matcher which matches if the match argument is less than the given value.

lessThanOrEqualTo(Object value) → Matcher

Returns a matcher which matches if the match argument is less than or equal to the given value.

matches(Pattern re) → Matcher

Returns a matcher that matches if the match argument is a string and matches the regular expression given by re.

orderedEquals(Iterable expected) → Matcher

Returns a matcher which matches Iterables that have the same length and the same elements as expected, in the same order.

pairwiseCompare<S, T>(Iterable<S> expected, bool comparator(S, T), String description) → Matcher

A pairwise matcher for Iterables.

predicate<T>(bool f(T), [String description = 'satisfies function']) → Matcher

Returns a matcher that uses an arbitrary function that returns true or false for the actual value.

same(Object? expected) → Matcher

Returns a matches that matches if the value is the same instance as expected, using identical.

startsWith(String prefixString) → Matcher

Returns a matcher that matches if the match argument is a string and starts with prefixString.

stringContainsInOrder(List<String> substrings) → Matcher

Returns a matcher that matches if the match argument is a string and contains a given list of substrings in relative order.

unorderedEquals(Iterable expected) → Matcher

Returns a matcher which matches Iterables that have the same length and the same elements as expected, but not necessarily in the same order.

unorderedMatches(Iterable expected) → Matcher

Returns a matcher which matches Iterables whose elements match the matchers in expected, but not necessarily in the same order.

wrapMatcher(Object? valueOrMatcher) → Matcher

Takes an argument and returns an equivalent Matcher.