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// Copyright (c) 2020 Uber Technologies, Inc.
//
// Permission is hereby granted, free of charge, to any person obtaining a copy
// of this software and associated documentation files (the "Software"), to deal
// in the Software without restriction, including without limitation the rights
// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
// copies of the Software, and to permit persons to whom the Software is
// furnished to do so, subject to the following conditions:
//
// The above copyright notice and this permission notice shall be included in
// all copies or substantial portions of the Software.
//
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
// THE SOFTWARE.
package atomic
import (
"bytes"
"io/ioutil"
"os"
"os/exec"
"path/filepath"
"reflect"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
)
func TestNocmpComparability(t *testing.T) {
tests := []struct {
desc string
give interface{}
comparable bool
}{
{
desc: "nocmp struct",
give: nocmp{},
},
{
desc: "struct with nocmp embedded",
give: struct{ nocmp }{},
},
{
desc: "pointer to struct with nocmp embedded",
give: &struct{ nocmp }{},
comparable: true,
},
// All exported types must be uncomparable.
{desc: "Bool", give: Bool{}},
{desc: "Duration", give: Duration{}},
{desc: "Error", give: Error{}},
{desc: "Float64", give: Float64{}},
{desc: "Int32", give: Int32{}},
{desc: "Int64", give: Int64{}},
{desc: "String", give: String{}},
{desc: "Uint32", give: Uint32{}},
{desc: "Uint64", give: Uint64{}},
{desc: "Value", give: Value{}},
}
for _, tt := range tests {
t.Run(tt.desc, func(t *testing.T) {
typ := reflect.TypeOf(tt.give)
assert.Equalf(t, tt.comparable, typ.Comparable(),
"type %v comparablity mismatch", typ)
})
}
}
// nocmp must not add to the size of a struct in-memory.
func TestNocmpSize(t *testing.T) {
type x struct{ _ int }
before := reflect.TypeOf(x{}).Size()
type y struct {
_ nocmp
_ x
}
after := reflect.TypeOf(y{}).Size()
assert.Equal(t, before, after,
"expected nocmp to have no effect on struct size")
}
// This test will fail to compile if we disallow copying of nocmp.
//
// We need to allow this so that users can do,
//
// var x atomic.Int32
// x = atomic.NewInt32(1)
func TestNocmpCopy(t *testing.T) {
type foo struct{ _ nocmp }
t.Run("struct copy", func(t *testing.T) {
a := foo{}
b := a
_ = b // unused
})
t.Run("pointer copy", func(t *testing.T) {
a := &foo{}
b := *a
_ = b // unused
})
}
const _badFile = `package atomic
import "fmt"
type Int64 struct {
nocmp
v int64
}
func shouldNotCompile() {
var x, y Int64
fmt.Println(x == y)
}
`
func TestNocmpIntegration(t *testing.T) {
tempdir, err := ioutil.TempDir("", "nocmp")
require.NoError(t, err, "unable to set up temporary directory")
defer os.RemoveAll(tempdir)
src := filepath.Join(tempdir, "src")
require.NoError(t, os.Mkdir(src, 0755), "unable to make source directory")
nocmp, err := ioutil.ReadFile("nocmp.go")
require.NoError(t, err, "unable to read nocmp.go")
require.NoError(t,
ioutil.WriteFile(filepath.Join(src, "nocmp.go"), nocmp, 0644),
"unable to write nocmp.go")
require.NoError(t,
ioutil.WriteFile(filepath.Join(src, "bad.go"), []byte(_badFile), 0644),
"unable to write bad.go")
var stderr bytes.Buffer
cmd := exec.Command("go", "build")
cmd.Dir = src
// Forget OS build enviroment and set up a minimal one for "go build"
// to run.
cmd.Env = []string{
"GOCACHE=" + filepath.Join(tempdir, "gocache"),
}
cmd.Stderr = &stderr
require.Error(t, cmd.Run(), "bad.go must not compile")
assert.Contains(t, stderr.String(),
"struct containing nocmp cannot be compared")
}
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