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

     1  // Copyright 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_test
    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/expression/function"
    25  )
    26  
    27  func TestFunctionRegistry(t *testing.T) {
    28  	require := require.New(t)
    29  
    30  	reg := function.NewRegistry()
    31  	name := "func"
    32  	var expected sql.Expression = expression.NewStar()
    33  	reg.Register(sql.Function1{
    34  		Name: name,
    35  		Fn:   func(arg sql.Expression) sql.Expression { return expected },
    36  	})
    37  
    38  	f, err := reg.Function(sql.NewEmptyContext(), name)
    39  	require.NoError(err)
    40  
    41  	e, err := f.NewInstance(nil)
    42  	require.Error(err)
    43  	require.Nil(e)
    44  
    45  	e, err = f.NewInstance([]sql.Expression{expression.NewStar()})
    46  	require.NoError(err)
    47  	require.Equal(expected, e)
    48  
    49  	e, err = f.NewInstance([]sql.Expression{expression.NewStar(), expression.NewStar()})
    50  	require.Error(err)
    51  	require.Nil(e)
    52  }
    53  
    54  func TestFunctionRegistryMissingFunction(t *testing.T) {
    55  	require := require.New(t)
    56  
    57  	reg := function.NewRegistry()
    58  	f, err := reg.Function(sql.NewEmptyContext(), "func")
    59  	require.Error(err)
    60  	require.Nil(f)
    61  }