Reset hash state between runs.

pkg/util/hash.go

@@ -26,6 +26,7 @@ import (
 // which follows pointers and prints actual values of the nested objects
 // ensuring the hash does not change when a pointer changes.
 func DeepHashObject(hasher hash.Hash, objectToWrite interface{}) {
+	hasher.Reset()
 	printer := spew.ConfigState{Indent: " ", SortKeys: true}
 	printer.Fprintf(hasher, "%#v", objectToWrite)
 }

pkg/util/hash_test.go

@@ -49,12 +49,18 @@ func TestDeepObjectPointer(t *testing.T) {
 		// Act
 		DeepHashObject(hasher1, myUni1)
 		hash1 := hasher1.Sum32()
+		DeepHashObject(hasher1, myUni1)
+		hash1a := hasher1.Sum32()
 		DeepHashObject(hasher2, myUni2)
 		hash2 := hasher2.Sum32()
 		DeepHashObject(hasher3, myUni3)
 		hash3 := hasher3.Sum32()
 
 		// Assert
+		if hash1 != hash1a {
+			t.Errorf("repeated hash of the same object produced different results: %d vs %d", hash1, hash1a)
+		}
+
 		if hash1 == hash2 {
 			t.Errorf("hash1 (%d) and hash2(%d) must be different because they have different values for wheel size", hash1, hash2)
 		}