TIL Rails: Errors In Test Cases Creates Floating Test Data

rails/errors-in-test-cases-creates-floating-test-data.md

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+# Errors In Test Cases Creates Floating Test Data
+
+If an exception is thrown when running your test cases, the test data created will NOT be rolled back.  
+This creates "floating" test data in your test database will may impact other test cases.
+
+The most common solution is to use the gem database_cleaner which basically clears out the entire test database
+whenever you start the test cases.  
+However, this makes your test cases run slower!  
+Furthermore, database_cleaner gem also don't address any test data leakage in your test cases.
+
+The easiest solution is to run `rake db:test:prepare` in your terminal.  
+This resets the entire test database so that there are no more floating test data in your test database.
+
+Every time you have a floating test data issue, you should run `rake db:test:prepare` 
+instead of using a slow solution like database_cleaner.