tSQLt AssertResultSetsHaveSameMetaData truncated response message in SQLTest - error-logging

Question

I'm trying to use tSQLt AssertResultSetsHaveSameMetaData to check the metadata from a query that returns a large number of columns.
When it fails the message that details the 'expected/but was' details is truncated, so I can't the two pieces of information to see what is wrong.
Is there a way to output the message so that it doesn't truncate (for example, to a file)?

Answer 1

It depends on what you are actually testing. I agree that on wide result sets the output from AssertResultsSetsHaveSameMetaData can be a little unwieldy. For stored procedures you would write your tests like this:
create procedure [ProcedureTests].[test SelectProcedure result set contract]
as
begin
create table #expected
(
name varchar(500) not null
, column_ordinal int not null identity(1,1)
, system_type_name varchar(500) not null
, Nullability varchar(16) not null
)
; with expectedCte (name, system_type_name, Nullability)
as
(
select 'ItemId' , 'int' , 'not null'
union all select 'ActorId' , 'int' , 'not null'
union all select 'LanId' , 'nvarchar(200)' , 'not null'
union all select 'ConsumerId' , 'int' , 'not null'
union all select 'ConsumerMoniker' , 'nvarchar(200)' , 'not null'
union all select 'ProfileTypeId' , 'int' , 'not null'
union all select 'ProfileTypeName' , 'varchar(50)' , 'not null'
union all select 'ProfileId' , 'int' , 'not null'
)
insert #expected
(
name
, system_type_name
, Nullability
)
select name, system_type_name, Nullability from expectedCte;
--! Act
select
name
, column_ordinal
, system_type_name
, case is_nullable when 1 then 'null' else 'not null' end as [Nullability]
into
#actual
from
sys.dm_exec_describe_first_result_set_for_object(object_id('mySchema.SelectProcedure'), 0);
--! Assert
exec tSQLt.AssertEqualsTable #expected, #actual;
end;
go
Whilst for views you could use this (slightly different) approach:
alter procedure [ViewTests].[test ViewName resultset contract]
as
begin
create table [ViewTests].[expected]
(
TransactionId int not null
, SourceId int not null
, SourceKey nvarchar(50) not null
, TransactionTypeId int not null
, TransactionStatusId int not null
, LastModified datetime not null
);
--! You comparison may be as simple as this (but see alternative approach below)
exec tSQLt.AssertEqualsTableSchema '[ViewTests].[expected]', 'mySchema.ViewName';
--!
--! Seems that is_nullable column on dm_exec_describe_first_result_set (used by tSQLt.AssertEqualsTableSchema)
--! can be a bit flakey where views are concerned so you may need to ignore nullability when testing
--! this view (so comment out that column in both SELECTs)
--!
select
c.name as [ColumnName]
, c.column_id as [ColumnPosition]
, case
when st.name in ('char', 'varchar', 'varbinary')
then st.name + '(' + case when c.max_length = -1 then 'max' else coalesce(cast(c.max_length as varchar(8)), '???') end + ')'
when st.name in ('nchar', 'nvarchar')
then st.name + '(' + case when c.max_length = -1 then 'max' else coalesce(cast(c.max_length / 2 as varchar(8)), '???') end + ')'
when st.name in ('decimal', 'numeric')
then st.name + '(' + coalesce(cast(c.precision as varchar(8)), '???') + ',' + coalesce(cast(c.scale as varchar(8)), '???') + ')'
when st.name in ('time', 'datetime2', 'datetimeoffset')
then st.name + '(' + coalesce(cast(c.precision as varchar(8)), '???') + ')'
else st.name
end as [DataType]
, c.[precision] as [NumericScale]
, c.scale as [NumericPrecision]
, c.collation_name as [CollationName]
, cast(case c.is_nullable when 1 then 'null' else 'not null' end as varchar(16)) as [Nullability]
into
#expected
from
sys.columns as c
inner join sys.types as st
on st.system_type_id = c.system_type_id
and st.user_type_id = c.user_type_id
where
c.[object_id] = object_id('[ViewTests].[expected]')
select
name as [ColumnName]
, column_ordinal as [ColumnPosition]
, system_type_name as [DataType]
, [precision ]as [NumericScale]
, scale as [NumericPrecision]
, collation_name as [CollationName]
, cast(case is_nullable when 1 then 'null' else 'not null' end as varchar(16)) as [Nullability]
into
#actual
from
sys.dm_exec_describe_first_result_set('select * from mySchema.ViewName, null, null)
exec tSQLt.AssertEqualsTable '#expected', '#actual' ;
end
go
In the even of any failures, the reason will be much clearer as the output is more like AssertEqualsTable.

Answer 2

You could try EXEC [tSQLt].[XmlResultFormatter]; before running your test. This is intended for use in "build server" scenarios, but could probably be pressed into service to show you more of the output in SSMS.