C#: Improve error message for missing explicit interface implementation

tamasvajk · tamasvajk · commit a4dec591c713 · 2023-06-06T15:01:54.000+02:00
diff --git a/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs b/csharp/extractor/Semmle.Extraction.CSharp/Entities/Method.cs
@@ -243,7 +243,12 @@ public static void AddExplicitInterfaceQualifierToId(Context cx, EscapingTextWri
             if (methodKind == MethodKind.ExplicitInterfaceImplementation)
             {
                 // Retrieve the original method kind
-                methodKind = methodDecl.ExplicitInterfaceImplementations.Select(m => m.MethodKind).FirstOrDefault();
+                if (methodDecl.ExplicitInterfaceImplementations.IsEmpty)
+                {
+                    throw new InternalError(methodDecl, $"Couldn't get the original method kind for explicit interface implementation");
+                }
+
+                methodKind = methodDecl.ExplicitInterfaceImplementations.Select(m => m.MethodKind).First();
             }
 
             switch (methodKind)

Original file line number	Diff line number	Diff line change
`@@ -243,7 +243,12 @@ public static void AddExplicitInterfaceQualifierToId(Context cx, EscapingTextWri`
`243`	`243`	`if (methodKind == MethodKind.ExplicitInterfaceImplementation)`
`244`	`244`	`{`
`245`	`245`	`// Retrieve the original method kind`
`246`		`- methodKind = methodDecl.ExplicitInterfaceImplementations.Select(m => m.MethodKind).FirstOrDefault();`
	`246`	`+ if (methodDecl.ExplicitInterfaceImplementations.IsEmpty)`
	`247`	`+ {`
	`248`	`+ throw new InternalError(methodDecl, $"Couldn't get the original method kind for explicit interface implementation");`
	`249`	`+ }`
	`250`	`+`
	`251`	`+ methodKind = methodDecl.ExplicitInterfaceImplementations.Select(m => m.MethodKind).First();`
`247`	`252`	`}`
`248`	`253`
`249`	`254`	`switch (methodKind)`