robustio_test.go

Documentation: golang.org/x/tools/internal/robustio

     1  // Copyright 2022 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 robustio_test
     6  
     7  import (
     8  	"os"
     9  	"path/filepath"
    10  	"runtime"
    11  	"testing"
    12  	"time"
    13  
    14  	"golang.org/x/tools/internal/robustio"
    15  )
    16  
    17  func checkOSLink(t *testing.T, err error) {
    18  	if err == nil {
    19  		return
    20  	}
    21  
    22  	t.Helper()
    23  	switch runtime.GOOS {
    24  	case "aix", "darwin", "dragonfly", "freebsd", "illumos", "linux", "netbsd", "openbsd", "solaris":
    25  		// Non-mobile OS known to always support os.Symlink and os.Link.
    26  		t.Fatal(err)
    27  	default:
    28  		t.Skipf("skipping due to error on %v: %v", runtime.GOOS, err)
    29  	}
    30  }
    31  
    32  func TestFileInfo(t *testing.T) {
    33  	// A nonexistent file has no ID.
    34  	nonexistent := filepath.Join(t.TempDir(), "nonexistent")
    35  	if _, _, err := robustio.GetFileID(nonexistent); err == nil {
    36  		t.Fatalf("GetFileID(nonexistent) succeeded unexpectedly")
    37  	}
    38  
    39  	// A regular file has an ID.
    40  	real := filepath.Join(t.TempDir(), "real")
    41  	if err := os.WriteFile(real, nil, 0644); err != nil {
    42  		t.Fatalf("can't create regular file: %v", err)
    43  	}
    44  	realID, realMtime, err := robustio.GetFileID(real)
    45  	if err != nil {
    46  		t.Fatalf("can't get ID of regular file: %v", err)
    47  	}
    48  
    49  	// Sleep so that we get a new mtime for subsequent writes.
    50  	time.Sleep(2 * time.Second)
    51  
    52  	// A second regular file has a different ID.
    53  	real2 := filepath.Join(t.TempDir(), "real2")
    54  	if err := os.WriteFile(real2, nil, 0644); err != nil {
    55  		t.Fatalf("can't create second regular file: %v", err)
    56  	}
    57  	real2ID, real2Mtime, err := robustio.GetFileID(real2)
    58  	if err != nil {
    59  		t.Fatalf("can't get ID of second regular file: %v", err)
    60  	}
    61  	if realID == real2ID {
    62  		t.Errorf("realID %+v == real2ID %+v", realID, real2ID)
    63  	}
    64  	if realMtime.Equal(real2Mtime) {
    65  		t.Errorf("realMtime %v == real2Mtime %v", realMtime, real2Mtime)
    66  	}
    67  
    68  	// A symbolic link has the same ID as its target.
    69  	t.Run("symlink", func(t *testing.T) {
    70  		symlink := filepath.Join(t.TempDir(), "symlink")
    71  		checkOSLink(t, os.Symlink(real, symlink))
    72  
    73  		symlinkID, symlinkMtime, err := robustio.GetFileID(symlink)
    74  		if err != nil {
    75  			t.Fatalf("can't get ID of symbolic link: %v", err)
    76  		}
    77  		if realID != symlinkID {
    78  			t.Errorf("realID %+v != symlinkID %+v", realID, symlinkID)
    79  		}
    80  		if !realMtime.Equal(symlinkMtime) {
    81  			t.Errorf("realMtime %v != symlinkMtime %v", realMtime, symlinkMtime)
    82  		}
    83  	})
    84  
    85  	// Two hard-linked files have the same ID.
    86  	t.Run("hardlink", func(t *testing.T) {
    87  		hardlink := filepath.Join(t.TempDir(), "hardlink")
    88  		checkOSLink(t, os.Link(real, hardlink))
    89  
    90  		hardlinkID, hardlinkMtime, err := robustio.GetFileID(hardlink)
    91  		if err != nil {
    92  			t.Fatalf("can't get ID of hard link: %v", err)
    93  		}
    94  		if realID != hardlinkID {
    95  			t.Errorf("realID %+v != hardlinkID %+v", realID, hardlinkID)
    96  		}
    97  		if !realMtime.Equal(hardlinkMtime) {
    98  			t.Errorf("realMtime %v != hardlinkMtime %v", realMtime, hardlinkMtime)
    99  		}
   100  	})
   101  }
   102
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