| // Copyright 2011 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package errors_test |
| |
| import ( |
| "errors" |
| "fmt" |
| "testing" |
| ) |
| |
| func TestNewEqual(t *testing.T) { |
| // Different allocations should not be equal. |
| if errors.New("abc") == errors.New("abc") { |
| t.Errorf(`New("abc") == New("abc")`) |
| } |
| if errors.New("abc") == errors.New("xyz") { |
| t.Errorf(`New("abc") == New("xyz")`) |
| } |
| |
| // Same allocation should be equal to itself (not crash). |
| err := errors.New("jkl") |
| if err != err { |
| t.Errorf(`err != err`) |
| } |
| } |
| |
| func TestErrorMethod(t *testing.T) { |
| err := errors.New("abc") |
| if err.Error() != "abc" { |
| t.Errorf(`New("abc").Error() = %q, want %q`, err.Error(), "abc") |
| } |
| } |
| |
| func ExampleNew() { |
| err := errors.New("emit macho dwarf: elf header corrupted") |
| if err != nil { |
| fmt.Print(err) |
| } |
| // Output: emit macho dwarf: elf header corrupted |
| } |
| |
| // The fmt package's Errorf function lets us use the package's formatting |
| // features to create descriptive error messages. |
| func ExampleNew_errorf() { |
| const name, id = "bimmler", 17 |
| err := fmt.Errorf("user %q (id %d) not found", name, id) |
| if err != nil { |
| fmt.Print(err) |
| } |
| // Output: user "bimmler" (id 17) not found |
| } |
| |
| func ExampleJoin() { |
| err1 := errors.New("err1") |
| err2 := errors.New("err2") |
| err := errors.Join(err1, err2) |
| fmt.Println(err) |
| if errors.Is(err, err1) { |
| fmt.Println("err is err1") |
| } |
| if errors.Is(err, err2) { |
| fmt.Println("err is err2") |
| } |
| // Output: |
| // err1 |
| // err2 |
| // err is err1 |
| // err is err2 |
| } |