github.com/cockroachdb/tools@v0.0.0-20230222021103-a6d27438930d/internal/robustio/robustio_test.go (about)

     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 TestFileInfo(t *testing.T) {
    18  	// A nonexistent file has no ID.
    19  	nonexistent := filepath.Join(t.TempDir(), "nonexistent")
    20  	if _, _, err := robustio.GetFileID(nonexistent); err == nil {
    21  		t.Fatalf("GetFileID(nonexistent) succeeded unexpectedly")
    22  	}
    23  
    24  	// A regular file has an ID.
    25  	real := filepath.Join(t.TempDir(), "real")
    26  	if err := os.WriteFile(real, nil, 0644); err != nil {
    27  		t.Fatalf("can't create regular file: %v", err)
    28  	}
    29  	realID, realMtime, err := robustio.GetFileID(real)
    30  	if err != nil {
    31  		t.Fatalf("can't get ID of regular file: %v", err)
    32  	}
    33  
    34  	// Sleep so that we get a new mtime for subsequent writes.
    35  	time.Sleep(2 * time.Second)
    36  
    37  	// A second regular file has a different ID.
    38  	real2 := filepath.Join(t.TempDir(), "real2")
    39  	if err := os.WriteFile(real2, nil, 0644); err != nil {
    40  		t.Fatalf("can't create second regular file: %v", err)
    41  	}
    42  	real2ID, real2Mtime, err := robustio.GetFileID(real2)
    43  	if err != nil {
    44  		t.Fatalf("can't get ID of second regular file: %v", err)
    45  	}
    46  	if realID == real2ID {
    47  		t.Errorf("realID %+v == real2ID %+v", realID, real2ID)
    48  	}
    49  	if realMtime.Equal(real2Mtime) {
    50  		t.Errorf("realMtime %v == real2Mtime %v", realMtime, real2Mtime)
    51  	}
    52  
    53  	// A symbolic link has the same ID as its target.
    54  	if runtime.GOOS != "plan9" {
    55  		symlink := filepath.Join(t.TempDir(), "symlink")
    56  		if err := os.Symlink(real, symlink); err != nil {
    57  			t.Fatalf("can't create symbolic link: %v", err)
    58  		}
    59  		symlinkID, symlinkMtime, err := robustio.GetFileID(symlink)
    60  		if err != nil {
    61  			t.Fatalf("can't get ID of symbolic link: %v", err)
    62  		}
    63  		if realID != symlinkID {
    64  			t.Errorf("realID %+v != symlinkID %+v", realID, symlinkID)
    65  		}
    66  		if !realMtime.Equal(symlinkMtime) {
    67  			t.Errorf("realMtime %v != symlinkMtime %v", realMtime, symlinkMtime)
    68  		}
    69  	}
    70  
    71  	// Two hard-linked files have the same ID.
    72  	if runtime.GOOS != "plan9" && runtime.GOOS != "android" {
    73  		hardlink := filepath.Join(t.TempDir(), "hardlink")
    74  		if err := os.Link(real, hardlink); err != nil {
    75  			t.Fatal(err)
    76  		}
    77  		hardlinkID, hardlinkMtime, err := robustio.GetFileID(hardlink)
    78  		if err != nil {
    79  			t.Fatalf("can't get ID of hard link: %v", err)
    80  		}
    81  		if realID != hardlinkID {
    82  			t.Errorf("realID %+v != hardlinkID %+v", realID, hardlinkID)
    83  		}
    84  		if !realMtime.Equal(hardlinkMtime) {
    85  			t.Errorf("realMtime %v != hardlinkMtime %v", realMtime, hardlinkMtime)
    86  		}
    87  	}
    88  }