Set default Contract exception to InvalidOperationException

JeremyCaney · JeremyCaney · commit 75487715265c · 2020-12-17T15:04:28.000-08:00
Previously, if `Contract.Requires(bool)` or `Contract.Assumes(bool)` were called without specifying an exception type, then an `Exception` was thrown. This is now updated to throw the more specific `InvalidOperationException`. If implementors want more control over this, they should prefer to call `Contract.Requires&lt;T&gt;(bool)` or `Contract.Assumes&lt;T&gt;(bool)`.

As `InvalidOperationException` derives from `Exception`, this shouldn't be a breaking change, but will provide implementors more flexibility in capturing exceptions raised by this library.
diff --git a/OnTopic/Internal/Diagnostics/Contract.cs b/OnTopic/Internal/Diagnostics/Contract.cs
@@ -51,14 +51,15 @@ public static class Contract {
     | METHOD: REQUIRES
     \-------------------------------------------------------------------------------------------------------------------------*/
     /// <summary>
-    ///   Will throw a <see cref="Exception"/> if the supplied expression evaluates to false.
+    ///   Will throw a <see cref="InvalidOperationException"/> if the supplied expression evaluates to false.
     /// </summary>
     /// <param name="isValid">An expression resulting in a boolean value indicating if an exception should be thrown.</param>
     /// <param name="errorMessage">Optionally provides an error message in case an exception is thrown.</param>
-    /// <exception cref="Exception">
+    /// <exception cref="InvalidOperationException">
     ///   Thrown when <paramref name="isValid"/> returns <see langword="true"/>.
     /// </exception>
-    public static void Requires(bool isValid, string? errorMessage = null) => Requires<Exception>(isValid, errorMessage);
+    public static void Requires(bool isValid, string? errorMessage = null) =>
+      Requires<InvalidOperationException>(isValid, errorMessage);
 
     /// <summary>
     ///   Will throw an <see cref="ArgumentNullException"/> if the supplied object is <see langword="null"/>.
@@ -118,7 +119,7 @@ or NotSupportedException
     | METHOD: ASSUME
     \-------------------------------------------------------------------------------------------------------------------------*/
     /// <summary>
-    ///   Ensures that a condition is met. If not, an <see cref="Exception"/> is thrown.
+    ///   Ensures that a condition is met. If not, an <see cref="InvalidOperationException"/> is thrown.
     /// </summary>
     /// <remarks>
     ///   This is virtually identical to <see cref="Requires(Boolean, String)"/> except that, syntactically, it is expected to
@@ -128,11 +129,11 @@ or NotSupportedException
     /// </remarks>
     /// <param name="isValid">An expression resulting in a boolean value indicating if an exception should be thrown.</param>
     /// <param name="errorMessage">Optionally provides an error message in case an exception is thrown.</param>
-    /// <exception cref="Exception">
+    /// <exception cref="InvalidOperationException">
     ///   Thrown when <paramref name="isValid"/> returns <see langword="true"/>.
     /// </exception>
     public static void Assume(bool isValid, string? errorMessage = null) =>
-      Requires<Exception>(isValid, errorMessage);
+      Requires<InvalidOperationException>(isValid, errorMessage);
 
     /// <summary>
     ///   Ensures that a condition is met. If not, the provided exception is thrown.
