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Unreleased

What’s new

  • New overloads of BeXmlSerializable and BeDataContractSerializable that allow EquivalencyOptions to be configured, allowing the use of member selection rules. - #3107

8.8.0

What’s new

  • Added WithoutMessage to allow asserting an exception message does not contain a wildcard pattern - #3100
  • Added support for MSTest 4 - #3111

Enhancements

  • Improved the way the differences are reported for long strings - #3101

8.7.1

Fixes

  • Fixed ambiguity when using Should() on a JsonNode derived class - #3102
  • JSON assertions did not properly handle floats, doubles and unsigned int/long - #3105

8.7.0

What’s new

  • Added support for System.Text.Json.JsonNode and JsonArray through new assertions as well as the BeEquivalentTo API - #3094
  • Added WithoutMessage to allow asserting an exception message does not contain a wildcard pattern - #3100

8.6.0

What’s new

  • Add Value.ThatMatches and Value.ThatSatifies to build inline assertions when using BeEquivalentTo - #3076

8.5.0

What’s new

  • Add WithStrictTyping and WithStrictTypingFor to BeEquivalentTo to ensure types also match - #3066

Fixes

  • Ensured WithTracing is safe when used with BeEquivalentTo globally - #3067

8.4.0

Enhancements

  • Added ExcludingMembersNamed to BeEquivalentTo to exclude fields and properties anywhere in the graph - #3062
  • Added Should().Throw(), ThrowAsync() and ThrowWithinAsync() flavors that don’t require a specific exception type - #3059

8.3.0

Enhancements

  • Clarify the date/time type when comparing non-compatible dates and times in BeEquivalentTo - #3049
  • Improve the rendering of exception messages when using WithMessage for better readability - #3039

8.2.0

Fixes

  • Fixed a regression from 8.1.0 where a NullReferenceException was thrown during subject identification - #3036

Enhancements

  • Better support for rendering multi-dimensional arrays in failure messages - #3009

8.1.1

Fixes

  • Fix a formatting exception when {} is used as a dictionary key - #3008
  • Removed the PowerShell script that opens the website because it misbehaves - #3030

8.1.0

Improvements

  • Improved subject identification when chaining multiple assertions using Which - #3000
  • All Should() methods on reference types are now annotated with the [NotNull] attribute for a better Fluent Assertions experience when nullable reference types are enabled - #2987
  • Provide a toggle to suppress the soft warning that commercial use requires a paid license - #2984

Fixes

  • Fixed a regression in which CompleteWithinAsync treated a canceled task as an exception - #2853

8.0.0

License Change

Versions 8 and beyond are/will be free for open-source projects and non-commercial use, but commercial use requires a paid license. Check out the license page for more information.

Version 7 will remain fully open-source indefinitely and receive bugfixes and other important corrections.

What’s new

  • Introduced a new assembly-level attribute that you can use to initialize Fluent Assertions before the first assertion - #2292
  • Ensure compatibility with .NET 8 - #2466
  • Add support for NUnit 4 - #2483
  • Added NotBeIn to check if a DateTime is not in a given DateTimeKind - #2536
  • Introduced a new Satisfy method available to all reference types to allow for nested assertions - #2597
  • Added BeNaN and NotBeNaN for assertions on float and double - #2606
  • Added option for event monitoring to ignore failing event accessors - #2629
  • Added the capability of associating IValueFormatters to a (nested) AssertionScope - #2676
  • Added support for throwing TUnit exceptions when using TUnit as your testing framework - #2758
  • Added a few more assertions on XElement - #2690
    • [Not]HaveElementWithValue
    • NotHaveElement
    • [Not]HaveAttribute
    • NotHaveAttributeWithValue
  • Added a few more assertions on XDocument - #2690
    • [Not]HaveElementWithValue
    • NotHaveElement
  • Added support for xUnit.net v3 - #2718

Improvements

  • Improve failure message for string assertions when checking for equality - #2307
  • Allow specifying EquivalencyOptions in string assertions - #2413
    • This also adds the capability to ignore casing, leading or trailing whitespace on strings when using BeEquivalentTo on object graphs or collections.
    • Also adds the capability to ignore the newline style on strings - #2565
  • You can mark all assertions in an assembly as custom assertions using the [CustomAssertionsAssembly] attribute - #2389
  • All Should() methods on reference types are now annotated with the [NotNull] attribute for a better Fluent Assertions experience when nullable reference types are enabled - #2380
  • All assertions that support chaining using the .Which construct will now amend the caller identifier - #2539
  • Introduced a MethodInfoFormatter and improved the PropertyInfoFormatter - #2539
  • Excluding() / For().Exclude() and Including() on BeEquivalentTo() now also accepts an anonymous object to include/exclude multiple members at once - #2488
  • You can exclude explicitly implemented properties from BeEquivalentTo via ExcludingExplicitlyImplementedProperties - #2851

Fixes

  • Fixed incorrect treatment of “\r\n” as new line - #2569
  • Fixed RaisePropertyChangeFor to return a filtered list of events - #2677
  • Including or excluding members did not work when WithMapping was used in BeEquivalentTo - #2860
  • Fix a crash when using WithStrictOrderingFor(x => x) with BeEquivalentTo - #2932

Breaking Changes (for users)

  • Moved support for DataSet, DataTable, DataRow and DataColumn into a new package FluentAssertions.DataSet - #2267
  • Removed obsolete ...OrEqualTo methods - #2269
    • GenericCollectionAssertions
      • HaveCountGreaterOrEqualTo: Use HaveCountGreaterThanOrEqualTo
      • HaveCountLessOrEqualTo: Use HaveCountLessThanOrEqualTo
    • ComparableTypeAssertions
      • BeGreaterOrEqualTo: Use BeGreaterThanOrEqualTo
      • BeLessOrEqualTo: Use BeLessThanOrEqualTo
    • SimpleTimeSpanAssertions
      • BeGreaterOrEqualTo: Use BeGreaterThanOrEqualTo
      • BeLessOrEqualTo: Use BeLessThanOrEqualTo
    • ExecutionTimeAssertions
      • BeGreaterOrEqualTo: Use BeGreaterThanOrEqualTo
      • BeLessOrEqualTo: Use BeLessThanOrEqualTo
  • Removed the DefaultValueFormatter.SpacesPerIndentionLevel property which was added during the development of v6, but wasn’t removed before the release of v6 - #2281
  • Dropped direct support for .NET Core 2.x and .NET Core 3.x - #2302
  • AllSatisfy now succeeds when asserting that an empty collection satisfies some predicates - #2321
  • OnlyContain now succeeds when asserting that an empty collection matches some predicates - #2350
  • Dropped support for BinaryFormatter - #2278
  • Renamed “…AssertionOptions” to “…Options” - #2414
    • EquivalencyAssertionOptions to EquivalencyOptions
    • EquivalencyAssertionOptions<TExpectation> to EquivalencyOptions<TExpectation>
    • IEquivalencyAssertionOptions to IEquivalencyOptions
    • SelfReferenceEquivalencyAssertionOptions<TSelf> to SelfReferenceEquivalencyOptions<TSelf>
  • Allow fluently calling WithoutMatchingRules and WithoutSelectionRules while using BeEquivalentTo - #2457
  • Removed utcNow overload for .Monitor<T>() - #2629
  • The semantics of BeLowerCased/BeUpperCased have been changed to align with the behavior of ToLower/ToUpper - #2660
  • Renamed HaveAttribute to HaveAttributeWithValue on XElement - #2690
  • Renamed RespectingRuntimeTypes to PreferringRuntimeMemberTypes and RespectingDeclaredTypes to PreferringDeclaredMemberTypes - #2866
  • Renamed ExcludingNestedObjects to WithoutRecursing to better describe its purpose - #2876
  • Removed direct support for assertions on HttpResponseMessage. Use FluentAssertions.Web instead. - #2909
  • Consolidated the configuration options under Configuration and Services into GlobalConfiguration accessible through AssertionEngine.Configuration and AssertionConfiguration.Current.Configuration - #2901
  • Removed support for setting configuration settings through an app.config file - #2901

Breaking Changes (for extensions)

  • Add ForConstraint to IAssertionsScope to support chaining .ForConstraint() after .Then - #2324
  • Refactored AsyncFunctionAssertions into real base class - #2359
    • Its constructor has been made protected.
    • Unused constructors have been removed.
    • Methods overwritten in GenericAsyncFunctionAssertions has been moved to NonGenericAsyncFunctionAssertions.
  • Moved the non-generic NotThrow and NotThrowAfter from DelegateAssertions<TDelegate, TAssertions> to ActionAssertions - #2371
  • Made EquivalencyValidator internal - #2854

7.2.0

Fixes

  • Fixed a regression in which CompleteWithinAsync treated a canceled task as an exception - #2853

Improvements

  • Improve failure message for string assertions when checking for equality - #2307
  • All Should() methods on reference types are now annotated with the [NotNull] attribute for a better Fluent Assertions experience when nullable reference types are enabled - #2987

7.1.0

Improvements

  • Added compatibility with xUnit.net v3 - #2970
  • Added support for throwing TUnit exceptions when using TUnit as your testing framework - #2971

7.0.0

Fixes

  • The expectation node identified as a cyclic reference is still compared to the subject node using simple equality - #2819
  • Fixed a problem in BeEquivalentTo where write-only properties would cause a NullReferenceException - #2836

Breaking Changes

  • Dropped direct support for .NET Core 2.x and .NET Core 3.x - #2302
  • Dropped support for NSpec3 test framework - #2356
  • Raised dependencies on System.Configuration.ConfigurationManager to 6.0.0 and System.Threading.Tasks.Extensions to 4.5.4 - #2673 and #2855

Fixes

  • Fixed a problem in BeEquivalentTo where write-only properties would cause a NullReferenceException - #2836

6.12.3

Fixes

  • The expectation node identified as a cyclic reference is still compared to the subject node using simple equality - 2819

6.12.2

Fixes

  • Better handling of normal vs explicitly implemented vs default interface properties - 2794

6.12.1

Improvements

  • Improve BeEmpty() and BeNullOrEmpty() performance for IEnumerable<T>, by materializing only the first item - #2530

Fixes

  • Fixed formatting error when checking nullable DateTimeOffset with BeWithin(...).Before(...) - #2312
  • BeEquivalentTo will now find and can map subject properties that are implemented through an explicitly-implemented interface - #2152
  • Fixed that the because and becauseArgs were not passed down the equivalency tree - #2318
  • BeEquivalentTo can again compare a non-generic IDictionary with a generic one - #2358
  • Fixed that the FormattingOptions were not respected in inner AssertionScope - #2329
  • Capitalize true and false in failure messages and make them formattable to a custom BooleanFormatter - #2390, #2393
  • Improved the failure message for NotBeOfType when wrapped in an AssertionScope and the subject is null - #2399
  • Improved the failure message for BeWritable/BeReadable when wrapped in an AssertionScope and the subject is read-only/write-only - #2399
  • Improved the failure message for ThrowExactly[Async] when wrapped in an AssertionScope and no exception is thrown - #2398
  • Improved the failure message for [Not]HaveExplicitProperty when wrapped in an AssertionScope and not implementing the interface - #2403
  • Improved the failure message for [Not]HaveExplicitMethod when wrapped in an AssertionScope and not implementing the interface - #2403
  • Changed BeEquivalentTo to exclude private protected members from the comparison - #2417
  • Fixed using BeEquivalentTo on an empty ArraySegment - #2445, #2511
  • BeEquivalentTo with a custom comparer can now handle null values - #2489
  • Ensured that nested calls to AssertionScope(context) create a chained context - #2607
  • One overload of the AssertionScope constructor would not create an actual scope associated with the thread - #2607
  • Fixed ThrowWithinAsync not respecting OperationCanceledException - #2614
  • Fixed using BeEquivalentTo with an IEqualityComparer targeting nullable types - #2648

6.12.0

What’s new

  • Added Be, NotBe and BeOneOf for object comparisons with custom comparer - #2111
  • Added BeSignedWithPublicKey() and BeUnsigned() for assertions on Assembly - #2207
  • Added NotContainItemsAssignableTo for asserting that a collection does not contain any items assignable to a specific type - #2266

Fixes

  • because and becauseArgs were not included in the error message when collections of enums were not equivalent - #2214
  • Improve caller identification for tests written in Visual Basic - #2254
  • Improved auto conversion to enums for objects of different integral type - #2261
  • Fixed exceptions when trying to auto convert strings or enums of different type to enums- #2261
  • Format records and anonymous objects with their member values instead of the generated ToString - #2144

6.11.0

What’s new

  • Added ThrowWithinAsync for assertions on Task - #1974
  • Added support for converting integers to enums using AutoConversion - #2147
  • Changed exception formatting to include any inner exception - #2150
  • Added an expression overload for WithoutStrictOrderingFor - #2151

Fixes

  • Improved robustness of several assertions when they’re wrapped in an AssertionScope - #2133
  • The maximum depth BeEquivalentTo uses for recursive comparisons was 9 instead of the expected 10 - #2145
  • Fixed .Excluding() and .For().Exclude() not working if root is a collection - #2135
  • Prevent InvalidOperationException when formatting a lambda expression calling a constructor - #2176

6.10.0

Fixes

  • Fixed hanging of CompleteWithinAsync when used with WithResult and AssertionScope - #2101
  • BeEquivalentTo no longer crashes on fields hiding base-class fields - #1990
  • Fixed System.Net.Http dependency declaration for net47 target framework to be a framework dependency instead of a nuget dependency - #2122

6.9.0

What’s new

  • Added ThatAre[Not]ValueTypes method for filtering the types - #2083
  • Added Imply method to BooleanAssertions - #2074
  • Added ThatAre[Not]Interfaces method for filtering the types - #2057
  • Added ThatAre[Not]Abstract method for filtering the types - #2058
  • Added ThatAre[Not]Sealed method for filtering the types - #2059
  • Added ThatAre[Not]Abstract methods to MethodInfoSelector.cs for filtering the methods - #2060
  • Added ThatAre[Not]Abstract, ThatAre[Not]Static and ThatAre[Not]Virtual properties for filtering in PropertyInfoSelector.cs - #2054
  • Added BeOneOf methods for object comparisons and IComparables - #2028
  • Added BeCloseTo and NotBeCloseTo to TimeOnly - #2030
  • Added new extension methods to be able to write Exactly.Times(n), AtLeast.Times(n) and AtMost.Times(n) in a more fluent way - #2047
  • Changed BeEquivalentTo to treat record structs like records, thus comparing them by member by default - #2009

Fixes

  • PropertyInfoSelector.ThatArePublicOrInternal now takes the setter into account when determining if a property is public or internal - #2082
  • Querying properties on classes, e.g. typeof(MyClass).Properties(), now also includes static properties - #2054
  • Nested AssertionScopes now print the inner scope reportables - #2044
  • Throw ArgumentException instead of ArgumentNullException when a required string argument is empty - #2023
  • Assertions on the ordering of a collection of strings now uses ordinal comparison when an IComparer<T> is not provided - #2075

6.8.0

What’s new

  • Added ContainInConsecutiveOrder and NotContainInConsecutiveOrder assertions to check if a collection contains items in a specific order and to be consecutive - #1963
  • Added NotCompleteWithinAsync for assertions on Task - #1967
  • Added CompleteWithinAsync and NotCompleteWithinAsync for non-generic TaskCompletionSource (.NET 6 and above) - #1961
  • Added a ParentType to IObjectInfo to help determining the parent in a call to Using/When constructs - #1950
  • Added a Monitor to EventAssertions to enable writing extension methods for event assertions. - #2008

Improvements

  • Updated exception messages to provide suggestions when incorrectly using Equals() - #2006
  • Included the time difference in the error message of BeCloseTo - #2013

Fixes

  • Fixed For/Exclude not excluding properties in objects in a collection - #1953
  • Changed MatchEquivalentOf to use CultureInfo.InvariantCulture instead of CultureInfo.CurrentCulture - #1985.
  • Fixed BeEquivalentTo not taking into account any record equivalency settings coming from the AssertionOptions - #1984
  • Fixed ExecutionTimeOf formatting failing when the expression includes {} - #1994

6.7.0

What’s new

  • Added BeDefined and NotBeDefined to assert on existence of an enum value - #1888
  • Added the ability to exclude fields & properties marked as non-browsable in the code editor from structural equality comparisons - #1807 & #1812
  • Assertions on the collection types in System.Data (DataSet.Tables, DataTable.Columns, DataTable.Rows) have been restored - #1812
  • Added For/Exclude to allow exclusion of members inside a collection - #1782
  • Added overload for HaveElement for XDocument and XElement to assert on number of XML nodes - #1880

Fixes

  • Fixed the failure message for regex matches (occurrence overload) to include the missing subject - #1913
  • Fixed WithArgs matching too many events when at least one argument matched the expected type - #1920

6.6.0

What’s New

  • Annotated [Not]MatchRegex(string) with [StringSyntax("Regex")] which IDEs can use to colorize the regular expression argument - #1816
  • Added support for .NET6 DateOnly struct - #1844
  • Added support for .NET6 TimeOnly struct - #1848
  • Added NotBe for nullable Boolean values - #1865
  • Added a new overload to MatchRegex() to assert on the number of regex matches - #1869
  • Added difference to numeric assertion failure messages - #1859

Fixes

  • EnumAssertions.Be did not determine the caller name - #1835
  • Ensure ExcludingMissingMembers doesn’t undo usage of WithMapping in BeEquivalentTo - #1838
  • Better handling of NaN in various numeric assertions - #1822 & #1867
  • WithMapping in BeEquivalentTo now also works when the root is a collection - #1858

6.5.1

Fixes

  • Fixed regression introduced in 6.5.0 where collection.Should().BeInAscendingOrder(x => x) would fail - #1802

6.5.0

What’s New

  • Added AllSatisfy for asserting all items in a collection satisfy an inspector - #1790
  • Added WithMapping option to BeEquivalentTo to map members with different names between the subject and expectation - #1742

Fixes

  • Improved the documentation on BeLowerCased and BeUpperCased for strings with non-alphabetic characters - #1792
  • Caller identification does not handle all arguments using new - #1794
  • Resolved an issue preventing HaveAccessModifier from correctly recognizing internal interfaces and enums - #1793
  • Improved tracing for nested AssertionScopes - #1797

Fixes (Extensibility)

  • Fixed a continuation issue when using ClearExpectation - #1791

6.4.0

What’s New

  • Added ThatAreStatic() and ThatAreNotStatic() for filtering in method assertions - #1740
  • Added new assertions for the HttpStatusCode of an HttpResponseMessage - #1737
  • Added non-generic overloads for WithInnerExceptionExactly and WithInnerException - #1769

Fixes

  • ContainItemsAssignableTo now expects at least one item assignable to T - #1765
  • Querying methods on classes, e.g. typeof(MyController).Methods(), now also includes static methods - #1740
  • Variable name is not captured after await assertion - #1770
  • OccurredEvent ordering on monitored object is now done via thread-safe counter - #1773
  • Avoid a NullReferenceException when testing an application compiled with .NET Native - #1776
  • [Not]Contain(key, value) for dictionary-like enumerables incorrectly checked if the key was present - #1786
  • Avoid throwing a FormatException when caller name determination returns an unformattable string - #1788

6.3.0

What’s New

  • Added ThatAreAsync() and ThatAreNotAsync() for filtering in method assertions - #1725
  • Added ThatAreVirtual() and ThatAreNotVirtual() for filtering in method assertions - #1744
  • Added collection content to assertion messages for HaveCountGreaterThan(), HaveCountGreaterThanOrEqualTo(), HaveCountLessThan() and HaveCountLessThanOrEqualTo() - #1760

Fixes

  • Prevent multiple enumeration of IEnumerables in parameter-less ContainSingle() - #1753
  • Changed HaveCount() assertion message order to state expected and actual collection count before dumping its content` - #1760
  • CompleteWithinAsync did not take initial sync computation into account when measuring execution time - 1762.

6.2.0

What’s New

  • Added new overloads to all GreaterOrEqualTo and LessOrEqualTo assertions, adding the word Than - #1673
  • BeAsync() and NotBeAsync() are now also available on MethodInfoSelectorAssertions - #1700

Fixes

  • Prevent exceptions when asserting on ImmutableArray<T> - #1668
  • At now retains the DateTimeKind and keeps sub-second precision when using a TimeSpan - #1687.
  • Removed iteration over enumerable when generating the BeEmpty assertion failure message - #1692.
  • Prevent ArgumentNullException when formatting a lambda expression containing an extension method - #1696
  • IgnoringCyclicReferences in BeEquivalentTo now works while comparing value types using ComparingByMembers - #1708
  • Using BeEquivalentTo on a collection with nested collections would complain about missing members - #1713
  • Formatting a lambda expression containing lifted operators - #1714.
  • Performance improvements in BeEquivalentTo by caching expensive Reflection operations - #1719

6.1.0

What’s New

  • Prevent asserting directly on AndConstraint - #1649
  • Added WithInnerExceptionExactly extension method on Task<ExceptionAssertions<T>> for easier use with ThrowAsync - #1658

Fixes

  • Resolved a significant performance degradation in BeEquivalentTo - #1660

6.0.0

What’s New

  • Added official support for .NET Core 3.0 - #1227.
  • Added WithOffset extension method on DateTime for easier creation of DateTimeOffset objects - #1235.
  • Added collectionOfStrings.Should().NotContainMatch() to assert that the collection does not contain a string that matches a wildcard pattern - #1246.
  • The Using/When option on BeEquivalentTo will now use the conversion rules when trying to match the predicate - #1257.
  • Added NotBeWritable to PropertyInfoSelectorAssertions to be able to assert that properties are not writable - #1269.
  • Added extension to assert TaskCompletionSource<T> - #1267.
  • Added the ability to pass an IEqualityComparer<T> through BeEquivalentTo(x => x.Using<MyComparer>()) - #1284.
  • Added NotBe to BooleanAssertions to be able to assert that a Boolean is not the expected value - #1290.
  • Make DefaultValueFormatter and EnumerableValueFormatter suitable for inheritance - #1295.
  • Added support for dictionary assertions on IReadOnlyDictionary<TKey, TValue> - #1298.
  • GenericAsyncFunctionAssertions now has AndWhichConstraint overloads for NotThrow[Async] and NotThrowAfter[Async] - #1289.
  • Added ReturnTypes to MethodInfoSelector to get all return types from all the methods selected
  • Added [Not]Be to MethodInfoSelector to check that methods [don’t] have specified access modifier
  • Added ThatAre[Not]Classes, ThatAre[Not]Static selectors to TypeSelector
  • Added ThatSatisfy to TypeSelector to filter types with specified predicate
  • Added UnwrapEnumerableTypes to TypeSelector to get the T type from types implementing IEnumerable<T>
  • Added UnwrapTaskTypes to TypeSelector to get the T type for any type that are Task<T> or ValueTask<T>
  • Added [Not]BeSealed to TypeSelectorAssertions
  • Added collection.Should().NotContainEquivalentOf to use object graph comparison rules to assert absence of an element in the collection - #1318.
  • Added [Not]BeInNamespace and [NotBeUnderNamespace] to TypeSelectorAssertions - #1329.
  • The Using option on BeEquivalentTo and on AssertionOptions.AssertEquivalencyUsing now supports custom IOrderingRule implementations #1337.
  • Added AllBe to StringCollectionAssertions to be able to assert that all strings in collection are equal to the specified string - #1332.
  • Added ForConstraint method to AssertionScope to open up OccurenceConstraint for usage in custom assertion extensions - #1341.
  • Added NotContainInOrder to CollectionAssertions and StringCollectionAssertions to be able to assert that the collection does not contain the specified elements in the exact same order, not necessarily consecutive - #1339.
  • Added async version of Where extension method to ExceptionAssertions to be able to check asynchronously thrown exception - #1352.
  • Added [Not]BeUpperCased and [Not]BeLowerCased to StringAssertions to be able to assert that a string is in upper or lower casing or not - #1357.
  • Added ObjectAssertions<TSubject, TAssertions> to ease creation of custom assertion classes - #1371.
  • Added ComparingBy{Members,Value}(Type) to allow specifying open generic types - #1389.
  • Added overload of CollectionAssertions.NotBeEquivalentTo that takes a config parameter` - #1408.
  • Changed StringAssertions.StartWith, StringAssertions.EndWith and their EquivalentOf versions to allow empty strings - #1413.
  • The equivalency assertions will now include the type of the member and whether it involves a field or property - #1379
  • Changed AttributeBasedFormatter to allow custom formatter selection based on the parent type - #1418.
  • Added nullable overload for Be and NotBe methods of DateTimeAssertions and DateTimeOffsetAssertions - #1427.
  • Added overload of Enumerating extension method to be able to force the enumeration of an object member -#1433
  • Add overloads of MatchRegex and NotMatchRegex that take System.Text.RegularExpressions.Regex -#1436
  • Added support for equivalency tests on System.Data types (DataSet, DataTable, DataColumn, DataRow, DataRelation, Constraint) - #1419.
  • Added WithParameterName extension to ease asserting on the parameter name for a thrown ArgumentException - #1466.
  • Added BeExactly assertions to verify a DateTimeOffset exactly, i.e both its date/time and its offset - #1609.
  • Added NotCompleteWithinAsync to TaskCompletionSourceAssertions - #1474.
  • Added HaveValue(decimal), HaveSameValueAs and HaveSameNameAs to EnumAssertions - #1479.
  • Added WithResult extension method to CompleteWithinAsync assertions for Task<T> and TaskCompletionSource<T> - #1478.
  • Added Satisfy to be able to compare a collection with a set of predicates in any order - #1500.
  • Added milliseconds formatting for error messages including TimeSpan - #1504.
  • Added AddReportable overload to AssertionScope for deferring reportable value calculation only on a test failure - #1515.
  • Added the possibility to set the maximum depth and other formatting settings either globally or per AssertionScope - #1469.
  • Added BeInAscendingOrder and BeInDescendingOrder for collections taking a lambda expression - #1526
  • Added [Not]BeWritable, [Not]BeSeekable, [Not]BeReadable, [Not]BeReadOnly, [Not]BeWriteOnly, [Not]HaveLength , [Not]HavePosition for Stream and [Not]HaveBufferSize for BufferedStream - #1543
  • Added native support for XDocument, XElement and XAttribute properties and fields to BeEquivalentTo - #1572
  • The equivalency failure message will include information on how tuples, anonymous types, records and other types are compared - #1571
  • Improved formatting a dictionary when key or value is a complex type - #1577.
  • Added NotBe(string) for symmetry with Be(string) for GuidAssertions - #1597.
  • Added BeOneOf for enum assertions - #1637
  • Homogenized assertion message formatting of predicate expressions - #1619.

Fixes

  • Reported actual value when it contained {{{{ or }}}} - #1234.
  • Changed dictionary assertion NotContainKeys to honour the key comparer if applicable - #1233.
  • Ensures that date time assertions like “a is less than an hour after b” don’t succeed when a - b == -30.Minutes() #1313.
  • Event raising assertions like WithSender and WithArgs will only return the events that match the constraints - #1321
  • Fixed an InvalidCastException that BeEquivalentTo could throw while debugging - #1325
  • Ensured that Given will no longer evaluate its predicate if the preceding FailWith raised an assertion failure - #1325
  • Improved the message that RaisePropertyChangeFor throws when the wrong property was detected - #1333
  • Guard against negative precision arguments for BeCloseTo and BeApproximately - #1386
  • Guard against implicitly or explicitly trying to compare primitive types by members - #1394.
  • Fixed formatting of brackets in expressions passed to ContainSingle(…) - #1406.
  • Fixed Contain, NotContain and OnlyContain to avoid multiple enumerations when the condition is false - #1421.
  • Added variable name and other useful and consistent information to XML assertions - #1440.
  • Sometimes BeEquivalentTo reported an incorrect message when a dictionary was missing a key - #1454
  • Some dictionary failures did not honor the user-provided reason - #1456
  • Restrict what types WhenTypeIs<T> can use and how Using<T> handles non-nullable types, see the Migration Guide for more details - #1494.
  • HaveElement did not ignore the xml namespace - #1541
  • Better parameter checking of TypeAssertions - #1550
  • [Not]HaveExplicitMethod did not mention the parameters in the failure message - #1550
  • Better parameter checking of PropertyInfoAssertions - #1558
  • Better parameter checking of MethodBaseAssertions and MethodInfoAssertions - #1559
  • Better parameter checking of AssemblyAssertions - #1561
  • Better parameter checking of PropertyInfoSelectorAssertions - #1565
  • Better parameter checking of MethodInfoSelectorAssertions - #1569
  • Better parameter checking of XDocumentAssertions, XElementAssertions and XAttributeAssertions - #1564
  • In a chained assertion API call, a second call to ForCondition should not even evaluate its lambda when the previous assertion failed - #1587
  • Added parameter checking for Be(string) for GuidAssertions - #1597.
  • Improved consistency of XML documentation on AssertionScope, ContinuedAssertionScope, and GivenSelector<T> methods. - #1606.
  • Handle WithDefaultIdentifier and WithExpectation correctly when an AssertionScope continues - #1610.
  • Improved stack trace when a property of an element of a generic collection throws an exception during GenericEnumerableEquivalencyStep in GenericCollectionAssertions - #1615.
  • Removed the type info from the failure message in equivalency checks - #1621.
  • Fixed a regression so that collections of similarly typed key-value pairs should be equivalent to a dictionary - #1603.
  • Fixed a regression where a nested class without suitable members inside a collection raised an exception - #1627.
  • Fixed support for covariant and inherited property exclusion and inclusion in BeEquivalentTo - #1631.
  • Reintroduced Match for enum assertions - #1637
  • Improved caller name determination by supporting multiple lines, comments and semicolons - #1435.

Breaking Changes

  • Dropped support for .NET Framework 4.5, .NET Standard 1.3 and 1.6 - #1227.
  • Dropped support for older test frameworks such as MSTest v1, NSpec v1 and v2, XUnit v1, Gallio and MBUnit - #1227.
  • Removed [Not]Have{Im,Ex}plictConversionOperator (they had typos) - #1221.
    • Use the equivalent assertions without the typo “plict” instead.
  • Removed NotBeAscendingInOrder/NotBeDescendingInOrder - #1221.
    • Use NotBeInAscendingOrder/NotBeInDescendingOrder instead.
  • Removed HasAttribute, HasMatchingAttribute and IsDecoratedWith(Type, bool) Type extensions - #1221.
    • Use IsDecoratedWith/IsDecoratedWithOrInherits instead.
  • Made EquivalencyAssertionOptionsExtentions internal (and fixed a typo in the type name) - #1221.
  • Changed ReferenceTypeAssertions.Subject to be readonly - #1229.
    • Set the Subject through the constructor instead.
  • Changed TypeAssertions.HaveAccessModifier return type from AndConstraint<Type> to AndConstraint<TypeAssertions> - #1159.
  • Changed TypeAssertions.NotHaveAccessModifier return type from AndConstraint<Type> to AndConstraint<TypeAssertions> - #1159.
  • Changed AllBeAssignableTo<T> and AllBeOfType<T> return type from AndConstraint<TAssertions> to AndWhichConstraint<TAssertions, IEnumerable<T>> - #1265.
  • The new extension on TaskCompletionSource<T> overlays the previously used assertions based on ObjectAssertions.
  • Removed [Not]BeCloseTo for DateTime[Offset] and TimeSpan that took an int precision - #1278.
    • Use the overloads that take a TimeSpan precision instead.
  • Aligned strings to be compared using Ordinal[Ignorecase] - #1283.
  • Changed AutoConversion to convert using CultureInfo.InvariantCulture instead of CultureInfo.CurrentCulture - #1283.
  • Renamed StartWithEquivalent and EndWithEquivalent to StartWithEquivalentOf and EndWithEquivalentOf to make the API for Equivalent methods consistent - #1292.
  • Several event raising assertion APIs will return an IEventRecording instead of IEventRecorder - #1321
  • The classes EventMonitor and RecordedEvent are now treated as internal code - #1321
  • Renamed method GetEventRecorder of interface IMonitor to GetRecordingFor and will return IEventRecording - #1321
  • Removed synchronous assertions on asynchronous operations (Throw, NotThrow, CompleteWithin, …) #1324
  • Do not modify SynchronizationContext.Current while asserting asynchronous operations. In case hitting deadlocks in your tests please check whether you mix synchronous and asynchronous operations. #1324
  • Moved [Not]HaveFlag from ObjectAssertions to EnumAssertions - #1375.
  • Requesting an unsupported test framework via Services.Configuration.TestFrameworkName or "FluentAssertions.TestFramework" now throws an exception instead of using the fallback - #1366.
  • Guard [Not]Match, [Not]MatchEquivalentOf, [Not]MatchRegex and [Not]ContainMatch against null or empty patterns - #1401.
  • Renamed WhichValue to WhoseValue - #1581
  • By default, records are now compared by their members. Can be overridden using ComparingRecordsByValue - #1571
  • Changed becauseArgs of [Not]Reference(Assembly) from string[] to object[] - #1459
  • Major overhaul on how enums are handled, see the Migration Guide for more details - #1479.
  • Removed support for non-generic collections, see the Migration Guide for more details - #1529.
  • Removed [Not]Contain(IEnumerable<T>, params T[]) - #1529.
  • Removed BeEquivalentTo(params object[]) - #1529.
  • Renamed EquivalencyStepCollection to EquivalencyPlan and AssertionOptions.EquivalencyCollection to EquivalencyPlan - #1539.
  • BeEquivalentTo will no longer include internal properties and fields, unless IncludingInternalProperties or IncludingInternalFields is used - #1575.
  • Renamed protected methods on DelegateAssertionsBase such as Throw and NotThrow to avoid confusion - #1642
  • Moved the properties of IMemberInfo.SelectedMemberInfo to IMemberInfo. Renamed IMemberInfo.SelectedMemberPath to Path and replaced SelectedMemberDescription by a combination of Path and Name - #1379
  • Changed [Not]Be on an IComparable<T> to use Equals(object) instead of CompareTo(T) and added [Not]BeRankedEquallyTo to use CompareTo(T) - #1177.

Breaking Changes (Extensibility)

  • Removed parameterless constructors from: CollectionAssertions, ReferenceTypeAssertions, MemberInfoAssertions, MethodBaseAssertions and MethodInfoAssertions - #1229.
    • Use the constructors taking a subject instead.
  • Restrict generic constraints on [Nullable]NumericAssertions<T> to IComparable<T> - #1266.
  • Changed return type of [Nullable]NumericAssertions.Subject from IComparable to T? and T, respectively - #1266.
  • Removed Succeeded and SourceSucceeded from Continuation and IAssertionScope - #1325
  • Made the extension methods under the FluentAssertions.Common namespace internal - #1376
  • The IEquivalencyValidationContext has undergone significant refactorings where its properties have been moved into the INode hierarchy and the two Reason and Tracer classes - #1379
  • The IMemberMatchingRule, IMemberSelectionRule and IOrderingRule have been changed to replace their dependency on SelectedMemberInfo to INode and its derivatives IMember - #1379
  • The SelectedMemberInfo class has been removed, since it main user, IMemberInfo has been flattened - #1379
  • Several methods that took an IMemberInfo, but could also act on other objects than a property or field now take an IObjectInfo - #1379
  • Pascal cased CallerIdentifier.logger - #1458.
  • Pascal cased SelfReferenceEquivalencyAssertionOptions.orderingRules - #1458.
  • Moved extension methods on ExceptionAssertions from AssertionExtensions to ExceptionAssertionsExtensions - #1471.
  • Moved Including(Expression<Func<IMemberInfo, bool>> predicate) from EquivalencyAssertionOptions<T> to SelfReferenceEquivalencyAssertionOptions<T> - #1495.
  • Formatter.ToString() and IValueFormatter now work with a FormattingOptions object that wraps the UseLineBreaks option - #1469.
  • Split-up the subject and expectation from IEquivalencyValidationContext into a new type Comparands. This affected IEquivalencyStep - #1539.
  • Moved the responsibility of IEquivalencyStep.CanHandle into Handle and replaced Handle’s return value with a more clearer EquivalencyResult - #1539
  • Simplified MemberSelectionContext which is used by IMemberSelectionRule to remove the need for extensions to understand the difference between run-time and compile-time types - #1539.
  • The implementations of IEquivalencyStep have moved to the FluentAssertions.Equivalency.Steps namespace - #1588.

5.10.3

Fixes

  • Fixed XPath index calculation in XML comparison when child node names are repeated in repeated parent nodes - #1273

5.10.2

Fixes

  • Added missing dependency on System.Xml - #79

5.10.1

This version was skipped.

5.10.0

What’s New

  • Added string.Should().NotBeEquivalentTo - #1134
  • Added collectionOfStrings.Should().ContainMatch() to assert that the collection contains at least one string that matches a wildcard pattern - #1138
  • Added overloads of NotBeInAscendingOrder and NotBeInDescendingOrder that take a property expression - #1140
  • Include the index in the XPath information reported while comparing XDocuments for equivalence - #1181
  • Added NotHaveSameCount and HaveSameCount for dictionary assertions - #1178
  • Extended string.Should().Contain() and string.Should().ContainEquivalentOf() to test the number of times a phrase exists in a string using theString.Should().Contain("is a", MoreThan.Thrice()) - #1145
  • Added support for methods returning ValueTask and ValueTask<T> - #1158
  • Added support for using SatisfyRespectively on all collections, including collections of string - #1201

Fixes

  • Updated the docs to clarify that CompleteWithin works on Func<Task> and not on Task directly - #1127.
  • Renamed collection assertion NotBeAscendingInOrder and NotBeDescendingInOrder to NotBeInAscendingOrder and NotBeInDescendingOrder (in a non-breaking way) - #1140
  • Collections containing nulls where not properly treated as equivalent by BeEquivalentTo - #1143
  • BeEquivalentTo now allows selecting an explicit interface member over a regular instance member when using RespectingDeclaredTypes and the expectation type is an interface - #1144
  • Fixed a crash that can occur when trying to determine the caller identity under .NET Native - #1149
  • Ensured that determining the caller identity works for namespaces that contain the phrase System and don’t match on partial namespace segments - #1193
  • BeEquivalentTo on an XDocument could report the incorrect path to a self-closing XML tag - #1170
  • BeEquivalentTo on multi-dimensional arrays with empty elements could cause an internal error - #1167
  • Several assertion APIs did not include the reason in the failure messages - #1172
  • A self-closing XML element was not treated as equivalent to an empty element with the same name - #1174
  • Ensure that type assertion ThatAreUnderNamespace handles types in the global namespaces correctly - #1197
  • When comparing whether two objects are equal, a conversion should be precision preserving - #1202
  • BeEquivalentTo on normal Tuples should use structural equivalency instead of treating them as value types - #1206
  • Some platforms throw reflection exceptions when trying to use ConfigurationManager. This is now handled more gracefully - #1210
  • Reintroduced the package dependency on System.Xml.Linq for .NET 4.5/4.7 - #79
  • Treat enums and their numeric representations in structural object graph comparisons the same - #1208

Thanks to contributors Ronald Kroon, Daniel Petrov, @david-a-jetter, Lukas Grützmacher and Ben Randall.

And special thanks to Matthias Koch to switch us over to the awesome Nuke build system.

5.9.0

What’s New

  • Added Match method to (nullable) numeric assertions - #1112

Fixes

  • Using a custom IAssertionStrategy with an AssertionScope did not always capture all assertion failures - #1118
  • Ensured null arguments are handled with clearer exception messages - #1117

Special thanks to contributors @liklainy and Amaury Levé.

5.8.0

What’s New

  • Added thread-safety to tests using AssertionScope while running many async tests concurrently - #1091
  • Allow users to specify a custom IAssertionStrategy for the assertion scope, for instance, to create screenshots when a test fails - #1094 & #906.
  • Supports .NET Core 3.0 Preview 7 - #1107

Fixes

  • Excluding with BeEquivalentTo did not always work well with overridden properties - #1087 & #1077
  • Failure message formatting threw a FormatException when a nested message contains braces - #1092
  • Fixed confusing (Not)BeAssignableTo failure messages - #1104 & #1103
  • Fixed a potential leakage of failure messages between multiple assertions - #1105

Kudos to conklinb and Amaury Levé for notable contributions and my partner-in-crime Jonas Nyrup for some of the fixes, a lot of (internal) quality improvements and his critical eye.

5.7.0

What’s New

  • Added official support for .NET Core 3 (Preview 5 or later) - #1057
  • Introduced SatisfyRespectively on collections - #1043
  • Added an alternative fluent syntax for evaluating/invoking actions - #1017
  • Added overloads of Invoking and Awaiting for different sets of generic parameters - #1051
  • NotThrowAfter is now also available for .NET Standard 1.3 and 1.6 - #1050
  • Added CompleteWithin to assert asynchronous operations complete within a time span - #1013/#1048
  • Added NotBeEquivalent for objects - #1071
  • Added WithMessage() for async exception assertions - #1052
  • Added extension methods like 100.Nanosecond() and 20.Microsecond() to represent time spans - #1069

Fixes

  • AllBeAssignableTo and AllBeOfType did not work for list of types - #1007
  • Backslashes in subject or expected result were not correctly shown in the message - #986
  • BeOfType does not attach to the AssertionScope correctly - #1002
  • Event monitoring did not detect events on interfaces - #821
  • Fix continuation on NotThrow(After) in chained AssertionScope invocations - #1031
  • Allow nesting equivalency checks in custom assertion rules when using BeEquivalentTo - #1033
  • Removed redundant use of the thread pool in async assertions - #1020
  • Improved formatting of multidimensional arrays - #1044
  • Better handling of exceptions wrapped in AggregateExceptions - #1041
  • Fix BadImageFormatException under the .NET Core 3.0 Preview - #1057
  • ThrowExactly and ThrowExactlyAsync now support expecting an AggregateException - #1046

Kudos to Lukas Grützmacher, Matthias Lischka, Christoffer Lette, Ed Ball, David Omid, mu88, Dmitriy Maksimov and Ivan Shimko for the contributions and Jonas Nyrup to make this release possible again.

5.6.0

Fixes

  • Provide opt-out to AssertionOptions(o => o.WithStrictOrdering()) -#974
  • Add collection assertion ContainEquivalentOf - #950
  • Add Should().NotThrowAfter assertion for actions - #942

Kudos to @BrunoJuchli, @matthiaslischka and @frederik-h for these amazing additions.

5.5.3

Fixes

  • Performance fixes in BeEquivalenTo - #935
  • Reverted 5.5.0 changes to AssertionScope to ensure binary compatibility - #977

5.5.2

Fixes

  • Allows BeEquivalentTo to handle a non-generic collection as the SUT - #975, #973
  • Optimized performance of IncludeMemberByPathSelectionRule - #969

5.5.1

What’s New

  • Now provides a hint when strings differ in length and contain differences - #915, #907
  • Added ThrowAsync, ThrowExactlyAsync and NotThrowAsync - #931
  • Added support for Should().Throw and Should().NotThrow for Func<T> - #951
  • Added support for private protected access modifier - #932
  • Updated BeApproximately to support nullable types for both the subject and the expectation nullable - #934
  • Added async version of ExecutionTime to - #938
  • Updated NotBeApproximately to accepting nullable subject and expectation - #939
  • type.Should().Be(type) now support open generics - #954, #955

Fixes

  • Minor performance improvements to prevent rendering messages if a test did not fail - #921, #915
  • Improve performance of Should().AllBeEquivalentTo() - #920, #914
  • Improve the presentation of enums to include the value and the number - #923, #897
  • BeEquivalentTo with WithStrictOrdering produced messy failure message - #918
  • Fixes detecting checking equivalency of a null subject to a dictionary - #933
  • Fixes duplicate conversions being mentioned in the output of the equivalency API - #941
  • Comparing an object graph against IEnumerable now works now as expected - #911
  • Selecting members during object graph assertions now better handles new overrides - #960, #956

Note In versions prior to 5.5, FA may have skipped certain properties in the equivalency comparison. #960 fixes this, so this may cause some breaking changes.

Lots of kudos @jnyrup and @krajek for a majority for the work in this release.