GV

GeezerVison

The World Wide Web, restored to 800 pixels of glory.

Home|About|Gaming cabinet|Archives|How it works|Starter sites

On this site

  • Sign in
  • ActionsCI/CD and automation
  • CodespacesCloud development environments
  • All Features
  • Documentation
  • Training
  • Certifications
  • Build with Copilot
  • Customize Copilot
  • Integrations
  • Trending repos
  • GitHub Sponsors
  • Developer articles
  • Enterprises

This view

  • Original page
  • New address

GeezerVison is showing github.com — sqlparser/ast_copy_on_rewrite_test.go at master · smlxl/sqlparser

This repository was archived by the owner on Apr 24, 2025. It is now read-only.

Expand file tree

/

ast_copy_on_rewrite_test.go

Copy path
More file actions
More file actions

Latest commit

 

History

History
History
128 lines (110 loc) · 3.65 KB
/

ast_copy_on_rewrite_test.go

Copy path

File metadata and controls

128 lines (110 loc) · 3.65 KB
Raw
Copy raw file
Download raw file
Open symbols panel
Edit and raw actions
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
/*
Copyright 2023 The Vitess Authors.
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 (
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestCopyOnRewrite(t *testing.T) {
parser := NewTestParser()
// rewrite an expression without changing the original
expr, err := parser.ParseExpr("a = b")
require.NoError(t, err)
out := CopyOnRewrite(expr, nil, func(cursor *CopyOnWriteCursor) {
col, ok := cursor.Node().(*ColName)
if !ok {
return
}
if col.Name.EqualString("a") {
cursor.Replace(NewIntLiteral("1"))
}
}, nil)
assert.Equal(t, "a = b", String(expr))
assert.Equal(t, "1 = b", String(out))
}
func TestCopyOnRewriteDeeper(t *testing.T) {
parser := NewTestParser()
// rewrite an expression without changing the original. the changed happens deep in the syntax tree,
// here we are testing that all ancestors up to the root are cloned correctly
expr, err := parser.ParseExpr("a + b * c = 12")
require.NoError(t, err)
var path []string
out := CopyOnRewrite(expr, nil, func(cursor *CopyOnWriteCursor) {
col, ok := cursor.Node().(*ColName)
if !ok {
return
}
if col.Name.EqualString("c") {
cursor.Replace(NewIntLiteral("1"))
}
}, func(before, _ SQLNode) {
path = append(path, String(before))
})
assert.Equal(t, "a + b * c = 12", String(expr))
assert.Equal(t, "a + b * 1 = 12", String(out))
expected := []string{ // this are all the nodes that we need to clone when changing the `c` node
"c",
"b * c",
"a + b * c",
"a + b * c = 12",
}
assert.Equal(t, expected, path)
}
func TestDontCopyWithoutRewrite(t *testing.T) {
parser := NewTestParser()
// when no rewriting happens, we want the original back
expr, err := parser.ParseExpr("a = b")
require.NoError(t, err)
out := CopyOnRewrite(expr, nil, func(cursor *CopyOnWriteCursor) {}, nil)
assert.Same(t, expr, out)
}
func TestStopTreeWalk(t *testing.T) {
parser := NewTestParser()
// stop walking down part of the AST
original := "a = b + c"
expr, err := parser.ParseExpr(original)
require.NoError(t, err)
out := CopyOnRewrite(expr, func(node, parent SQLNode) bool {
_, ok := node.(*BinaryExpr)
return !ok
}, func(cursor *CopyOnWriteCursor) {
col, ok := cursor.Node().(*ColName)
if !ok {
return
}
cursor.Replace(NewStrLiteral(col.Name.String()))
}, nil)
assert.Equal(t, original, String(expr))
assert.Equal(t, "'a' = b + c", String(out)) // b + c are unchanged since they are under the + (*BinaryExpr)
}
func TestStopTreeWalkButStillVisit(t *testing.T) {
parser := NewTestParser()
// here we are asserting that even when we stop at the binary expression, we still visit it in the post visitor
original := "1337 = b + c"
expr, err := parser.ParseExpr(original)
require.NoError(t, err)
out := CopyOnRewrite(expr, func(node, parent SQLNode) bool {
_, ok := node.(*BinaryExpr)
return !ok
}, func(cursor *CopyOnWriteCursor) {
switch cursor.Node().(type) {
case *BinaryExpr:
cursor.Replace(NewStrLiteral("johnny was here"))
case *ColName:
t.Errorf("should not visit ColName in the post")
}
}, nil)
assert.Equal(t, original, String(expr))
assert.Equal(t, "1337 = 'johnny was here'", String(out)) // b + c are replaced
}
You are visitor 01402520 — GeezerVison does not store the pages you look up.
Best viewed with Netscape Navigator 4.7 or Internet Explorer 6 at 800×600. No cookies required.