Test when _unique_error returns false

t/exasol.t

@@ -363,6 +363,7 @@ DBI: {
     $DBI::errstr = 'object foo not found';
     ok $exa->_no_table_error, 'Should now have table error';
     ok $exa->_no_column_error, 'Should now have no column error';
+    ok !$exa->_unique_error, 'Unique constraints not supported by Exasol';
 }
 
 is_deeply [$exa->_limit_offset(8, 4)],

t/lib/DBIEngineTest.pm

@@ -1621,6 +1621,16 @@ sub run {
                 'Cannot log change "{change}": The deploy script is not unique',
                 change => $name,
             ), 'And it should report the script is not unique';
+
+            # Make sure log_deploy_change dies on any other error.
+            MOCKPROJECT: {
+                my $engine_mocker = Test::MockModule->new(ref $engine);
+                $engine_mocker->mock(_unique_error => 0);
+                throws_ok { $engine->log_deploy_change($rev_change) } 'App::Sqitch::X',
+                    'Should re-throw if not a unique erorr';
+                is $@->ident, $DBI::state, 'Mode should be the error state';
+                is $@->message, $DBI::errstr, 'Should not have the underlying DB error';
+            }
         }
 
         # Make a temporary copy of the deploy file so we can restore it later.

t/snowflake.t

@@ -354,6 +354,7 @@ DBI: {
     $DBI::state = '42703';
     ok !$snow->_no_table_error, 'Should again have no table error';
     ok $snow->_no_column_error, 'Should now have no column error';
+    ok !$snow->_unique_error, 'Unique constraints not supported by Snowflake';
 }
 
 is_deeply [$snow->_limit_offset(8, 4)],