GUAC-4961 Change how reference image is found

If recording, don't look for the reference image in the bundle, since
this sets the file name for generation later. Instead, look for a local
copy of the file (since we won't be recording tests in CI), so that's where
the new file gets generated.

Author: lj-dickey

Sources/SnapshotTesting/AssertSnapshot.swift

@@ -221,10 +221,15 @@ public func verifySnapshot<Value, Format>(
 
     let testName = sanitizePathComponent(testName)
 
-       // Check the bundle for the resource first, then the file system
-        let thisBundle = Bundle(for: CleanCounterBetweenTestCases.self)
-        let resourcePath = thisBundle.path(forResource: "\(testName).\(identifier)",  ofType: snapshotting.pathExtension)
-        var snapshotFileUrlCandidate = resourcePath.map({ URL(fileURLWithPath: $0) })
+        // Check the bundle for the resource first, then the file system
+        // But, if we're recording, don't bother checking the bundle, since we aren't comparing it to anything, and
+        // want the new file to be generated in the source directory, not the bundle.
+        var snapshotFileUrlCandidate: URL?
+        if !recording {
+            let thisBundle = Bundle(for: CleanCounterBetweenTestCases.self)
+            let resourcePath = thisBundle.path(forResource: "\(testName).\(identifier)",  ofType: snapshotting.pathExtension)
+            snapshotFileUrlCandidate = resourcePath.map({ URL(fileURLWithPath: $0) })
+        }
         if snapshotFileUrlCandidate == nil {
             snapshotFileUrlCandidate = snapshotDirectoryUrl
                 .appendingPathComponent("\(testName).\(identifier)")