precedence_test.go

/*
Copyright 2017 Google Inc.

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/

package sqlparser

import (
	"fmt"
	"testing"
)

func readable(node Expr) string {
	switch node := node.(type) {
	case *OrExpr:
		return fmt.Sprintf("(%s or %s)", readable(node.Left), readable(node.Right))
	case *AndExpr:
		return fmt.Sprintf("(%s and %s)", readable(node.Left), readable(node.Right))
	case *BinaryExpr:
		return fmt.Sprintf("(%s %s %s)", readable(node.Left), node.Operator, readable(node.Right))
	case *IsExpr:
		return fmt.Sprintf("(%s %s)", readable(node.Expr), node.Operator)
	default:
		return String(node)
	}
}

func TestAndOrPrecedence(t *testing.T) {
	validSQL := []struct {
		input  string
		output string
	}{{
		input:  "select * from a where a=b and c=d or e=f",
		output: "((a = b and c = d) or e = f)",
	}, {
		input:  "select * from a where a=b or c=d and e=f",
		output: "(a = b or (c = d and e = f))",
	}}
	for _, tcase := range validSQL {
		tree, err := Parse(tcase.input)
		if err != nil {
			t.Error(err)
			continue
		}
		expr := readable(tree.(*Select).Where.Expr)
		if expr != tcase.output {
			t.Errorf("Parse: \n%s, want: \n%s", expr, tcase.output)
		}
	}
}

func TestPlusStarPrecedence(t *testing.T) {
	validSQL := []struct {
		input  string
		output string
	}{{
		input:  "select 1+2*3 from a",
		output: "(1 + (2 * 3))",
	}, {
		input:  "select 1*2+3 from a",
		output: "((1 * 2) + 3)",
	}}
	for _, tcase := range validSQL {
		tree, err := Parse(tcase.input)
		if err != nil {
			t.Error(err)
			continue
		}
		expr := readable(tree.(*Select).SelectExprs[0].(*AliasedExpr).Expr)
		if expr != tcase.output {
			t.Errorf("Parse: \n%s, want: \n%s", expr, tcase.output)
		}
	}
}

func TestIsPrecedence(t *testing.T) {
	validSQL := []struct {
		input  string
		output string
	}{{
		input:  "select * from a where a+b is true",
		output: "((a + b) is true)",
	}, {
		input:  "select * from a where a=1 and b=2 is true",
		output: "(a = 1 and (b = 2 is true))",
	}, {
		input:  "select * from a where (a=1 and b=2) is true",
		output: "((a = 1 and b = 2) is true)",
	}}
	for _, tcase := range validSQL {
		tree, err := Parse(tcase.input)
		if err != nil {
			t.Error(err)
			continue
		}
		expr := readable(tree.(*Select).Where.Expr)
		if expr != tcase.output {
			t.Errorf("Parse: \n%s, want: \n%s", expr, tcase.output)
		}
	}
}