[Issue #24] Throw exception when file path is null (#62)

docs/pages/faqs.md

@@ -28,3 +28,11 @@ There are currently three solutions for this issue.
 ```
 
 For more information see this issue: [theramis/snapper#16](https://github.com/theramis/Snapper/issues/16)
+
+### Why am I getting a `UnableToDetermineTestFilePathException`?
+```
+Snapper.Exceptions.UnableToDetermineTestFilePathException : Unable to determine the file path of the test method. 
+Make sure optimisation of the test project is disabled. See https://theramis.github.io/Snapper/#/pages/faqs for more info.
+```
+
+This can happen when the PDB files are not generated for the test project. Try setting the `<Optimize>false</Optimize>` or `<DebugType>full</DebugType>` settings in your projects csproj file. See above for more details on how to set these.

project/Snapper/Core/Messages.cs

@@ -37,5 +37,10 @@ public const string TestMethodNotFoundMessage
 
         public const string MalformedJsonSnapshotMessage
             = "The snapshot provided contains malformed JSON. See inner exception for details.";
+
+        public const string UnableToDetermineTestFilePathMessage
+            = "Unable to determine the file path of the test method. " +
+              "Make sure optimisation of the test project is disabled. " +
+              "See https://theramis.github.io/Snapper/#/pages/faqs for more info.";
     }
 }

project/Snapper/Core/TestMethodResolver/TestMethodResolver.cs

@@ -1,4 +1,5 @@
-using System.Collections.Generic;
+using System;
+using System.Collections.Generic;
 using System.Diagnostics;
 using System.Linq;
 using System.Reflection;
@@ -23,19 +24,30 @@ private static IEnumerable<ITestMethod> GetTestMethods(MemberInfo method, string
 
         public ITestMethod ResolveTestMethod()
         {
-            var stackTrace = new StackTrace(1, true);
-            foreach (var stackFrame in stackTrace.GetFrames() ?? new StackFrame[0])
+            try
             {
-                var method = stackFrame.GetMethod();
+                var stackTrace = new StackTrace(1, true);
+                foreach (var stackFrame in stackTrace.GetFrames() ?? new StackFrame[0])
+                {
+                    var method = stackFrame.GetMethod();
 
-                if (IsAsyncMethod(method))
-                    method = GetMethodBaseOfAsyncMethod(method);
+                    if (IsAsyncMethod(method))
+                        method = GetMethodBaseOfAsyncMethod(method);
 
-                if (IsSnapperMethod(method))
-                    continue;
+                    if (IsSnapperMethod(method))
+                        continue;
 
-                if (TryGetTestMethod(method, stackFrame.GetFileName(), out var testMethod))
-                    return testMethod;
+                    if (TryGetTestMethod(method, stackFrame.GetFileName(), out var testMethod))
+                        return testMethod;
+                }
+            }
+            catch (UnableToDetermineTestFilePathException)
+            {
+                throw;
+            }
+            catch (Exception ex)
+            {
+                throw new SupportedTestMethodNotFoundException(ex);
             }
 
             throw new SupportedTestMethodNotFoundException();
@@ -74,6 +86,11 @@ private static bool TryGetTestMethod(MemberInfo method, string fileName, out ITe
                 if (tm.IsTestMethod())
                 {
                     testMethod = tm;
+
+                    if (fileName == null)
+                    {
+                        throw new UnableToDetermineTestFilePathException();
+                    }
                     return true;
                 }
             }

project/Snapper/Exceptions/SupportedTestMethodNotFoundException.cs

@@ -9,5 +9,10 @@ public SupportedTestMethodNotFoundException()
             : base(Messages.TestMethodNotFoundMessage)
         {
         }
+
+        public SupportedTestMethodNotFoundException(Exception baseException)
+            : base(Messages.TestMethodNotFoundMessage, baseException)
+        {
+        }
     }
 }

project/Snapper/Exceptions/UnableToDetermineTestFilePathException.cs

@@ -0,0 +1,13 @@
+using System;
+using Snapper.Core;
+
+namespace Snapper.Exceptions
+{
+    internal class UnableToDetermineTestFilePathException : Exception
+    {
+        public UnableToDetermineTestFilePathException()
+            : base(Messages.UnableToDetermineTestFilePathMessage)
+        {
+        }
+    }
+}