| // 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" |
| "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 |
| }) |
| } |
| |
| // Fake go.mod with no dependencies. |
| const _exampleGoMod = `module example.com/nocmp` |
| |
| 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 := t.TempDir() |
| |
| nocmp, err := os.ReadFile("nocmp.go") |
| require.NoError(t, err, "unable to read nocmp.go") |
| |
| require.NoError(t, |
| os.WriteFile(filepath.Join(tempdir, "go.mod"), []byte(_exampleGoMod), 0o644), |
| "unable to write go.mod") |
| |
| require.NoError(t, |
| os.WriteFile(filepath.Join(tempdir, "nocmp.go"), nocmp, 0o644), |
| "unable to write nocmp.go") |
| |
| require.NoError(t, |
| os.WriteFile(filepath.Join(tempdir, "bad.go"), []byte(_badFile), 0o644), |
| "unable to write bad.go") |
| |
| var stderr bytes.Buffer |
| cmd := exec.Command("go", "build") |
| cmd.Dir = tempdir |
| // Create a minimal build environment with only HOME set so that "go |
| // build" has somewhere to put the cache and other Go files in. |
| cmd.Env = []string{"HOME=" + filepath.Join(tempdir, "home")} |
| cmd.Stderr = &stderr |
| require.Error(t, cmd.Run(), "bad.go must not compile") |
| |
| assert.Contains(t, stderr.String(), |
| "struct containing nocmp cannot be compared") |
| } |