#28: Synergy.Contracts: Added sth.FailIfNull() extension method

synergy-software · Feb 3, 2024 · 3acff68 · 3acff68
1 parent 9524ef5
commit 3acff68
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Showing 6 changed files with 27 additions and 7 deletions.
diff --git a/...ntracts.Test/Architecture/Public/Api.of.Synergy.Contracts.DotNet6_0.verified.md b/...ntracts.Test/Architecture/Public/Api.of.Synergy.Contracts.DotNet6_0.verified.md
@@ -72,7 +72,7 @@
    ) : T? [Extension, NotNull, AssertionMethod, ContractAnnotation]
  - Fail.FailIfNull<T>(
      value: T? [CanBeNull, AssertionCondition, NoEnumeration],
-     name: string [NotNull, NotNull]
+     name: string? [Nullable, CallerArgumentExpression, Optional]
    ) : T? [Extension, NotNull, AssertionMethod, ContractAnnotation]
  - Fail.IfArgumentEmpty(
      argumentValue: string [CanBeNull, AssertionCondition],

diff --git a/...ntracts.Test/Architecture/Public/Api.of.Synergy.Contracts.DotNet7_0.verified.md b/...ntracts.Test/Architecture/Public/Api.of.Synergy.Contracts.DotNet7_0.verified.md
@@ -72,7 +72,7 @@
    ) : T? [Extension, NotNull, AssertionMethod, ContractAnnotation]
  - Fail.FailIfNull<T>(
      value: T? [CanBeNull, AssertionCondition, NoEnumeration],
-     name: string [NotNull, NotNull]
+     name: string? [Nullable, CallerArgumentExpression, Optional]
    ) : T? [Extension, NotNull, AssertionMethod, ContractAnnotation]
  - Fail.IfArgumentEmpty(
      argumentValue: string [CanBeNull, AssertionCondition],

diff --git a/...ntracts.Test/Architecture/Public/Api.of.Synergy.Contracts.DotNet8_0.verified.md b/...ntracts.Test/Architecture/Public/Api.of.Synergy.Contracts.DotNet8_0.verified.md
@@ -72,7 +72,7 @@
    ) : T? [Extension, NotNull, AssertionMethod, ContractAnnotation]
  - Fail.FailIfNull<T>(
      value: T? [CanBeNull, AssertionCondition, NoEnumeration],
-     name: string [NotNull, NotNull]
+     name: string? [Nullable, CallerArgumentExpression, Optional]
    ) : T? [Extension, NotNull, AssertionMethod, ContractAnnotation]
  - Fail.IfArgumentEmpty(
      argumentValue: string [CanBeNull, AssertionCondition],

diff --git a/Contracts/Synergy.Contracts.Test/Failures/Doubles/Contractor.cs b/Contracts/Synergy.Contracts.Test/Failures/Doubles/Contractor.cs
@@ -64,8 +64,8 @@ public string GetName()
         [NotNull]
         public string GetCity()
         {
-            return this.Address.FailIfNull(nameof(this.Address))
-                       .City.FailIfNull(nameof(this.Address.City));
+            return this.Address.FailIfNull()
+                       .City.FailIfNull();
         }
 
         public void SetPersonName([NotNull] string firstName, [NotNull] string lastName)

diff --git a/Contracts/Synergy.Contracts.Test/Failures/FailNullabilityTest.cs b/Contracts/Synergy.Contracts.Test/Failures/FailNullabilityTest.cs
@@ -26,6 +26,20 @@ public void FailIfNull(object someNullObject)
             Assert.That(exception.Message, Is.EqualTo("'someNullObject' is null; and it shouldn't be;"));
         }
 
+        [Test]
+        [TestCaseSource(nameof(FailNullabilityTest.GetNulls))]
+        public void FailIfNullCallerArgumentExpression(object someNullObject)
+        {
+            // ACT
+            var exception = Assert.Throws<DesignByContractViolationException>(
+                // ReSharper disable once ExpressionIsAlwaysNull
+                () => someNullObject.FailIfNull()
+            );
+
+            // ASSERT
+            Assert.That(exception.Message, Is.EqualTo("'someNullObject' is null; and it shouldn't be;"));
+        }
+
         [Test]
         [TestCaseSource(nameof(FailNullabilityTest.GetNulls))]
         public void FailIfNullWithViolationMessage(object someNullObject)
@@ -46,6 +60,7 @@ public void FailIfNullSuccess(object thisIsNotNull)
         {
             // ACT
             thisIsNotNull.FailIfNull(nameof(thisIsNotNull));
+            thisIsNotNull.FailIfNull();
         }
 
         [Test]
@@ -92,7 +107,7 @@ public void OrFail(object thisMustBeNull)
 
         [Test]
         [TestCaseSource(nameof(FailNullabilityTest.GetNulls))]
-        public void OrFailNetCore(object thisMustBeNull)
+        public void OrFailCallerArgumentExpression(object thisMustBeNull)
         {
             // ACT
             var exception = Assert.Throws<DesignByContractViolationException>(

diff --git a/Contracts/Synergy.Contracts/Failures/FailNullability.cs b/Contracts/Synergy.Contracts/Failures/FailNullability.cs
@@ -20,7 +20,12 @@ static partial class Fail
         public static T FailIfNull<T>(
             [CanBeNull] [AssertionCondition(AssertionConditionType.IS_NOT_NULL)] [NoEnumeration]
             this T value,
-            [NotNull] [System.Diagnostics.CodeAnalysis.NotNull] string name)
+#if NET6_0_OR_GREATER
+            [System.Runtime.CompilerServices.CallerArgumentExpression("value")] string? name = null
+#else
+            string name
+#endif
+            )
         {
             Fail.RequiresArgumentName(name);
             return value.FailIfNull(Violation.WhenVariableIsNull(name));