github.com/dolthub/go-mysql-server@v0.18.0/sql/expression/function/if_test.go (about)

     1  // Copyright 2020-2021 Dolthub, Inc.
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package function
    16  
    17  import (
    18  	"testing"
    19  
    20  	"github.com/stretchr/testify/require"
    21  
    22  	"github.com/dolthub/go-mysql-server/sql"
    23  	"github.com/dolthub/go-mysql-server/sql/expression"
    24  	"github.com/dolthub/go-mysql-server/sql/types"
    25  )
    26  
    27  func TestIf(t *testing.T) {
    28  	testCases := []struct {
    29  		expr     sql.Expression
    30  		row      sql.Row
    31  		expected interface{}
    32  	}{
    33  		{eq(lit(1, types.Int64), lit(1, types.Int64)), sql.Row{"a", "b"}, "a"},
    34  		{eq(lit(1, types.Int64), lit(0, types.Int64)), sql.Row{"a", "b"}, "b"},
    35  		{eq(lit(1, types.Int64), lit(1, types.Int64)), sql.Row{1, 2}, 1},
    36  		{eq(lit(1, types.Int64), lit(0, types.Int64)), sql.Row{1, 2}, 2},
    37  		{eq(lit(nil, types.Int64), lit(1, types.Int64)), sql.Row{"a", "b"}, "b"},
    38  		{eq(lit(1, types.Int64), lit(1, types.Int64)), sql.Row{nil, "b"}, nil},
    39  	}
    40  
    41  	for _, tc := range testCases {
    42  		f := NewIf(
    43  			tc.expr,
    44  			expression.NewGetField(0, types.LongText, "true", true),
    45  			expression.NewGetField(1, types.LongText, "false", true),
    46  		)
    47  
    48  		v, err := f.Eval(sql.NewEmptyContext(), tc.row)
    49  		require.NoError(t, err)
    50  		require.Equal(t, tc.expected, v)
    51  	}
    52  }
    53  
    54  func eq(left, right sql.Expression) sql.Expression {
    55  	return expression.NewEquals(left, right)
    56  }
    57  
    58  func lit(n interface{}, typ sql.Type) sql.Expression {
    59  	return expression.NewLiteral(n, typ)
    60  }
    61  
    62  func col(idx int, typ sql.Type, db, table, col string) sql.Expression {
    63  	return expression.NewGetFieldWithTable(idx, 0, typ, db, table, col, false)
    64  }