Add Imply() to BooleanAssertions (#2074)

fluentassertions · Jan 3, 2023 · 482d5a0 · 482d5a0
1 parent c6d8bfa
commit 482d5a0
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Showing 10 changed files with 216 additions and 133 deletions.
diff --git a/Src/FluentAssertions/Primitives/BooleanAssertions.cs b/Src/FluentAssertions/Primitives/BooleanAssertions.cs
@@ -118,6 +118,37 @@ public AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", pa
         return new AndConstraint<TAssertions>((TAssertions)this);
     }
 
+    /// <summary>
+    /// Asserts that the value implies the specified <paramref name="consequent"/> value.
+    /// </summary>
+    /// <param name="consequent">The right hand side of the implication</param>
+    /// <param name="because">
+    /// A formatted phrase as is supported by <see cref="string.Format(string,object[])" /> explaining why the assertion
+    /// is needed. If the phrase does not start with the word <i>because</i>, it is prepended automatically.
+    /// </param>
+    /// <param name="becauseArgs">
+    /// Zero or more objects to format using the placeholders in <paramref name="because"/>.
+    /// </param>
+    public AndConstraint<TAssertions> Imply(bool consequent,
+        string because = "",
+        params object[] becauseArgs)
+    {
+        bool? antecedent = Subject;
+
+        Execute.Assertion
+            .ForCondition(antecedent is not null)
+            .BecauseOf(because, becauseArgs)
+            .WithExpectation("Expected {context:antecedent} ({0}) to imply consequent ({1}){reason}, ", antecedent, consequent)
+            .FailWith("but found null.")
+            .Then
+            .ForCondition(!antecedent.Value || consequent)
+            .FailWith("but it did not.")
+            .Then
+            .ClearExpectation();
+
+        return new AndConstraint<TAssertions>((TAssertions)this);
+    }
+
     /// <inheritdoc/>
     public override bool Equals(object obj) =>
         throw new NotSupportedException("Equals is not part of Fluent Assertions. Did you mean Be() instead?");

diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net47.verified.txt
@@ -1822,6 +1822,7 @@ namespace FluentAssertions.Primitives
         public FluentAssertions.AndConstraint<TAssertions> BeFalse(string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> BeTrue(string because = "", params object[] becauseArgs) { }
         public override bool Equals(object obj) { }
+        public FluentAssertions.AndConstraint<TAssertions> Imply(bool consequent, string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", params object[] becauseArgs) { }
     }
     public class DateTimeAssertions : FluentAssertions.Primitives.DateTimeAssertions<FluentAssertions.Primitives.DateTimeAssertions>

diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/net6.0.verified.txt
@@ -1847,6 +1847,7 @@ namespace FluentAssertions.Primitives
         public FluentAssertions.AndConstraint<TAssertions> BeFalse(string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> BeTrue(string because = "", params object[] becauseArgs) { }
         public override bool Equals(object obj) { }
+        public FluentAssertions.AndConstraint<TAssertions> Imply(bool consequent, string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", params object[] becauseArgs) { }
     }
     public class DateOnlyAssertions : FluentAssertions.Primitives.DateOnlyAssertions<FluentAssertions.Primitives.DateOnlyAssertions>

diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp2.1.verified.txt
@@ -1822,6 +1822,7 @@ namespace FluentAssertions.Primitives
         public FluentAssertions.AndConstraint<TAssertions> BeFalse(string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> BeTrue(string because = "", params object[] becauseArgs) { }
         public override bool Equals(object obj) { }
+        public FluentAssertions.AndConstraint<TAssertions> Imply(bool consequent, string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", params object[] becauseArgs) { }
     }
     public class DateTimeAssertions : FluentAssertions.Primitives.DateTimeAssertions<FluentAssertions.Primitives.DateTimeAssertions>

diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netcoreapp3.0.verified.txt
@@ -1822,6 +1822,7 @@ namespace FluentAssertions.Primitives
         public FluentAssertions.AndConstraint<TAssertions> BeFalse(string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> BeTrue(string because = "", params object[] becauseArgs) { }
         public override bool Equals(object obj) { }
+        public FluentAssertions.AndConstraint<TAssertions> Imply(bool consequent, string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", params object[] becauseArgs) { }
     }
     public class DateTimeAssertions : FluentAssertions.Primitives.DateTimeAssertions<FluentAssertions.Primitives.DateTimeAssertions>

diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.0.verified.txt
@@ -1773,6 +1773,7 @@ namespace FluentAssertions.Primitives
         public FluentAssertions.AndConstraint<TAssertions> BeFalse(string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> BeTrue(string because = "", params object[] becauseArgs) { }
         public override bool Equals(object obj) { }
+        public FluentAssertions.AndConstraint<TAssertions> Imply(bool consequent, string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", params object[] becauseArgs) { }
     }
     public class DateTimeAssertions : FluentAssertions.Primitives.DateTimeAssertions<FluentAssertions.Primitives.DateTimeAssertions>

diff --git a/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt b/Tests/Approval.Tests/ApprovedApi/FluentAssertions/netstandard2.1.verified.txt
@@ -1822,6 +1822,7 @@ namespace FluentAssertions.Primitives
         public FluentAssertions.AndConstraint<TAssertions> BeFalse(string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> BeTrue(string because = "", params object[] becauseArgs) { }
         public override bool Equals(object obj) { }
+        public FluentAssertions.AndConstraint<TAssertions> Imply(bool consequent, string because = "", params object[] becauseArgs) { }
         public FluentAssertions.AndConstraint<TAssertions> NotBe(bool unexpected, string because = "", params object[] becauseArgs) { }
     }
     public class DateTimeAssertions : FluentAssertions.Primitives.DateTimeAssertions<FluentAssertions.Primitives.DateTimeAssertions>