FakeTable with tSQLt remove triggers - triggers

Question

I have jsut started to use tSQLt and is about to test a trigger. I call the FakeTable procedure and do my test but the trigger is not executed. If don't use FakeTable the trigger is executed. That seems to be really bad and I canät find any info that there is any method to readded them.
Then I thought the triggers are removed by FakeTable but I can recreate them after the call and did the following code in my test:
DECLARE #createTrigger NVARCHAR(MAX);
SELECT #createTrigger = OBJECT_DEFINITION(OBJECT_ID('MoveDataFromAToB'))
EXEC tSQLt.FakeTable 'dbo.A';
EXEC(#createTrigger);
I got the following error: "There is already an object named 'MoveDataFromAToB' in the database.{MoveDataFromAToB,14} (There was also a ROLLBACK ERROR --> The current transaction cannot be committed and cannot be rolled back to a savepoint. Roll back the entire transaction.{Private_RunTest,60})"
Anyone that have any experience with tSQLt and know anyworkaround for this problem?

Answer 1

There is an ApplyTrigger method on the tSQLt backlog, but it is not finished yet. For now you should be able to use this code in your test:
DECLARE #createTrigger NVARCHAR(MAX);
SELECT #createTrigger = OBJECT_DEFINITION(OBJECT_ID('MoveDataFromAToB'));
DROP TRIGGER MoveDataFromAToB;
EXEC tSQLt.FakeTable 'dbo.A';
EXEC(#createTrigger);
You need to drop the existing trigger as FakeTable does not drop the original table. It just renames it, which leaves the old trigger intact; hence the name collision you did see.
The rollback that tSQLt executes at the end of every test will put the dropped trigger back in place (unless you are doing something really bad in your code). If you are worried about that use sp_rename instead of drop on the trigger.
I would put all this into a helper stored procedure within the test class and call it from the tests that need it. That way, once we have a better solution implemented in tSQLt you will have to change only one place in your code.

Answer 2

Thanks Sebastian for your answer. It really helped me too :)
I made a stored proc for the code you gave. I will use this until the 'ApplyTrigger' function is available:
CREATE PROCEDURE [tSQLt].[FakeTableWithTrigger]
#TableName NVARCHAR(MAX),
#TriggerName NVARCHAR(MAX),
#SchemaName NVARCHAR(MAX) = NULL, --parameter preserved for backward compatibility. Do not use. Will be removed soon.
#Identity BIT = NULL,
#ComputedColumns BIT = NULL,
#Defaults BIT = NULL
AS
BEGIN
DECLARE #createTrigger NVARCHAR(MAX);
SELECT #createTrigger = OBJECT_DEFINITION(OBJECT_ID(#TriggerName));
EXEC('DROP TRIGGER ' + #TriggerName);
EXEC tSQLt.FakeTable #TableName, #SchemaName, #Identity, #ComputedColumns, #Defaults;
EXEC(#createTrigger);
END
An example of it's useage in a test is:
exec tSQLt.FakeTableWithTrigger 'dbo.MyTable', 'MyTable_SyncTrigger', #Identity = 1