Source file src/os/error_test.go

     1  // Copyright 2012 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package os_test
     6  
     7  import (
     8  	"errors"
     9  	"fmt"
    10  	"io/fs"
    11  	"os"
    12  	"path/filepath"
    13  	"testing"
    14  )
    15  
    16  func TestErrIsExist(t *testing.T) {
    17  	f, err := os.CreateTemp("", "_Go_ErrIsExist")
    18  	if err != nil {
    19  		t.Fatalf("open ErrIsExist tempfile: %s", err)
    20  		return
    21  	}
    22  	defer os.Remove(f.Name())
    23  	defer f.Close()
    24  	f2, err := os.OpenFile(f.Name(), os.O_RDWR|os.O_CREATE|os.O_EXCL, 0600)
    25  	if err == nil {
    26  		f2.Close()
    27  		t.Fatal("Open should have failed")
    28  		return
    29  	}
    30  	if s := checkErrorPredicate("os.IsExist", os.IsExist, err, fs.ErrExist); s != "" {
    31  		t.Fatal(s)
    32  		return
    33  	}
    34  }
    35  
    36  func testErrNotExist(t *testing.T, name string) string {
    37  	originalWD, err := os.Getwd()
    38  	if err != nil {
    39  		t.Fatal(err)
    40  	}
    41  
    42  	f, err := os.Open(name)
    43  	if err == nil {
    44  		f.Close()
    45  		return "Open should have failed"
    46  	}
    47  	if s := checkErrorPredicate("os.IsNotExist", os.IsNotExist, err, fs.ErrNotExist); s != "" {
    48  		return s
    49  	}
    50  
    51  	err = os.Chdir(name)
    52  	if err == nil {
    53  		if err := os.Chdir(originalWD); err != nil {
    54  			t.Fatalf("Chdir should have failed, failed to restore original working directory: %v", err)
    55  		}
    56  		return "Chdir should have failed, restored original working directory"
    57  	}
    58  	if s := checkErrorPredicate("os.IsNotExist", os.IsNotExist, err, fs.ErrNotExist); s != "" {
    59  		return s
    60  	}
    61  	return ""
    62  }
    63  
    64  func TestErrIsNotExist(t *testing.T) {
    65  	tmpDir := t.TempDir()
    66  	name := filepath.Join(tmpDir, "NotExists")
    67  	if s := testErrNotExist(t, name); s != "" {
    68  		t.Fatal(s)
    69  		return
    70  	}
    71  
    72  	name = filepath.Join(name, "NotExists2")
    73  	if s := testErrNotExist(t, name); s != "" {
    74  		t.Fatal(s)
    75  		return
    76  	}
    77  }
    78  
    79  func checkErrorPredicate(predName string, pred func(error) bool, err, target error) string {
    80  	if !pred(err) {
    81  		return fmt.Sprintf("%s does not work as expected for %#v", predName, err)
    82  	}
    83  	if !errors.Is(err, target) {
    84  		return fmt.Sprintf("errors.Is(%#v, %#v) = false, want true", err, target)
    85  	}
    86  	return ""
    87  }
    88  
    89  type isExistTest struct {
    90  	err   error
    91  	is    bool
    92  	isnot bool
    93  }
    94  
    95  var isExistTests = []isExistTest{
    96  	{&fs.PathError{Err: fs.ErrInvalid}, false, false},
    97  	{&fs.PathError{Err: fs.ErrPermission}, false, false},
    98  	{&fs.PathError{Err: fs.ErrExist}, true, false},
    99  	{&fs.PathError{Err: fs.ErrNotExist}, false, true},
   100  	{&fs.PathError{Err: fs.ErrClosed}, false, false},
   101  	{&os.LinkError{Err: fs.ErrInvalid}, false, false},
   102  	{&os.LinkError{Err: fs.ErrPermission}, false, false},
   103  	{&os.LinkError{Err: fs.ErrExist}, true, false},
   104  	{&os.LinkError{Err: fs.ErrNotExist}, false, true},
   105  	{&os.LinkError{Err: fs.ErrClosed}, false, false},
   106  	{&os.SyscallError{Err: fs.ErrNotExist}, false, true},
   107  	{&os.SyscallError{Err: fs.ErrExist}, true, false},
   108  	{nil, false, false},
   109  }
   110  
   111  func TestIsExist(t *testing.T) {
   112  	for _, tt := range isExistTests {
   113  		if is := os.IsExist(tt.err); is != tt.is {
   114  			t.Errorf("os.IsExist(%T %v) = %v, want %v", tt.err, tt.err, is, tt.is)
   115  		}
   116  		if is := errors.Is(tt.err, fs.ErrExist); is != tt.is {
   117  			t.Errorf("errors.Is(%T %v, fs.ErrExist) = %v, want %v", tt.err, tt.err, is, tt.is)
   118  		}
   119  		if isnot := os.IsNotExist(tt.err); isnot != tt.isnot {
   120  			t.Errorf("os.IsNotExist(%T %v) = %v, want %v", tt.err, tt.err, isnot, tt.isnot)
   121  		}
   122  		if isnot := errors.Is(tt.err, fs.ErrNotExist); isnot != tt.isnot {
   123  			t.Errorf("errors.Is(%T %v, fs.ErrNotExist) = %v, want %v", tt.err, tt.err, isnot, tt.isnot)
   124  		}
   125  	}
   126  }
   127  
   128  type isPermissionTest struct {
   129  	err  error
   130  	want bool
   131  }
   132  
   133  var isPermissionTests = []isPermissionTest{
   134  	{nil, false},
   135  	{&fs.PathError{Err: fs.ErrPermission}, true},
   136  	{&os.SyscallError{Err: fs.ErrPermission}, true},
   137  }
   138  
   139  func TestIsPermission(t *testing.T) {
   140  	for _, tt := range isPermissionTests {
   141  		if got := os.IsPermission(tt.err); got != tt.want {
   142  			t.Errorf("os.IsPermission(%#v) = %v; want %v", tt.err, got, tt.want)
   143  		}
   144  		if got := errors.Is(tt.err, fs.ErrPermission); got != tt.want {
   145  			t.Errorf("errors.Is(%#v, fs.ErrPermission) = %v; want %v", tt.err, got, tt.want)
   146  		}
   147  	}
   148  }
   149  
   150  func TestErrPathNUL(t *testing.T) {
   151  	f, err := os.CreateTemp("", "_Go_ErrPathNUL\x00")
   152  	if err == nil {
   153  		f.Close()
   154  		t.Fatal("TempFile should have failed")
   155  	}
   156  	f, err = os.CreateTemp("", "_Go_ErrPathNUL")
   157  	if err != nil {
   158  		t.Fatalf("open ErrPathNUL tempfile: %s", err)
   159  	}
   160  	defer os.Remove(f.Name())
   161  	defer f.Close()
   162  	f2, err := os.OpenFile(f.Name(), os.O_RDWR, 0600)
   163  	if err != nil {
   164  		t.Fatalf("open ErrPathNUL: %s", err)
   165  	}
   166  	f2.Close()
   167  	f2, err = os.OpenFile(f.Name()+"\x00", os.O_RDWR, 0600)
   168  	if err == nil {
   169  		f2.Close()
   170  		t.Fatal("Open should have failed")
   171  	}
   172  }
   173  
   174  func TestPathErrorUnwrap(t *testing.T) {
   175  	pe := &fs.PathError{Err: fs.ErrInvalid}
   176  	if !errors.Is(pe, fs.ErrInvalid) {
   177  		t.Error("errors.Is failed, wanted success")
   178  	}
   179  }
   180  
   181  type myErrorIs struct{ error }
   182  
   183  func (e myErrorIs) Is(target error) bool { return target == e.error }
   184  
   185  func TestErrorIsMethods(t *testing.T) {
   186  	if os.IsPermission(myErrorIs{fs.ErrPermission}) {
   187  		t.Error("os.IsPermission(err) = true when err.Is(fs.ErrPermission), wanted false")
   188  	}
   189  }
   190  

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