read_test.go

     1  // Copyright 2009 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  	"bytes"
     9  	. "os"
    10  	"path/filepath"
    11  	"runtime"
    12  	"testing"
    13  )
    14  
    15  func checkNamedSize(t *testing.T, path string, size int64) {
    16  	dir, err := Stat(path)
    17  	if err != nil {
    18  		t.Fatalf("Stat %q (looking for size %d): %s", path, size, err)
    19  	}
    20  	if dir.Size() != size {
    21  		t.Errorf("Stat %q: size %d want %d", path, dir.Size(), size)
    22  	}
    23  }
    24  
    25  func TestReadFile(t *testing.T) {
    26  	t.Parallel()
    27  
    28  	filename := "rumpelstilzchen"
    29  	contents, err := ReadFile(filename)
    30  	if err == nil {
    31  		t.Fatalf("ReadFile %s: error expected, none found", filename)
    32  	}
    33  
    34  	filename = "read_test.go"
    35  	contents, err = ReadFile(filename)
    36  	if err != nil {
    37  		t.Fatalf("ReadFile %s: %v", filename, err)
    38  	}
    39  
    40  	checkNamedSize(t, filename, int64(len(contents)))
    41  }
    42  
    43  func TestWriteFile(t *testing.T) {
    44  	t.Parallel()
    45  
    46  	f, err := CreateTemp("", "os-test")
    47  	if err != nil {
    48  		t.Fatal(err)
    49  	}
    50  	defer f.Close()
    51  	defer Remove(f.Name())
    52  
    53  	msg := "Programming today is a race between software engineers striving to " +
    54  		"build bigger and better idiot-proof programs, and the Universe trying " +
    55  		"to produce bigger and better idiots. So far, the Universe is winning."
    56  
    57  	if err := WriteFile(f.Name(), []byte(msg), 0644); err != nil {
    58  		t.Fatalf("WriteFile %s: %v", f.Name(), err)
    59  	}
    60  
    61  	data, err := ReadFile(f.Name())
    62  	if err != nil {
    63  		t.Fatalf("ReadFile %s: %v", f.Name(), err)
    64  	}
    65  
    66  	if string(data) != msg {
    67  		t.Fatalf("ReadFile: wrong data:\nhave %q\nwant %q", string(data), msg)
    68  	}
    69  }
    70  
    71  func TestReadOnlyWriteFile(t *testing.T) {
    72  	if Getuid() == 0 {
    73  		t.Skipf("Root can write to read-only files anyway, so skip the read-only test.")
    74  	}
    75  	if runtime.GOOS == "wasip1" {
    76  		t.Skip("no support for file permissions on " + runtime.GOOS)
    77  	}
    78  	t.Parallel()
    79  
    80  	// We don't want to use CreateTemp directly, since that opens a file for us as 0600.
    81  	filename := filepath.Join(t.TempDir(), "blurp.txt")
    82  
    83  	shmorp := []byte("shmorp")
    84  	florp := []byte("florp")
    85  	err := WriteFile(filename, shmorp, 0444)
    86  	if err != nil {
    87  		t.Fatalf("WriteFile %s: %v", filename, err)
    88  	}
    89  	err = WriteFile(filename, florp, 0444)
    90  	if err == nil {
    91  		t.Fatalf("Expected an error when writing to read-only file %s", filename)
    92  	}
    93  	got, err := ReadFile(filename)
    94  	if err != nil {
    95  		t.Fatalf("ReadFile %s: %v", filename, err)
    96  	}
    97  	if !bytes.Equal(got, shmorp) {
    98  		t.Fatalf("want %s, got %s", shmorp, got)
    99  	}
   100  }
   101  
   102  func TestReadDir(t *testing.T) {
   103  	t.Parallel()
   104  
   105  	dirname := "rumpelstilzchen"
   106  	_, err := ReadDir(dirname)
   107  	if err == nil {
   108  		t.Fatalf("ReadDir %s: error expected, none found", dirname)
   109  	}
   110  
   111  	dirname = "."
   112  	list, err := ReadDir(dirname)
   113  	if err != nil {
   114  		t.Fatalf("ReadDir %s: %v", dirname, err)
   115  	}
   116  
   117  	foundFile := false
   118  	foundSubDir := false
   119  	for _, dir := range list {
   120  		switch {
   121  		case !dir.IsDir() && dir.Name() == "read_test.go":
   122  			foundFile = true
   123  		case dir.IsDir() && dir.Name() == "exec":
   124  			foundSubDir = true
   125  		}
   126  	}
   127  	if !foundFile {
   128  		t.Fatalf("ReadDir %s: read_test.go file not found", dirname)
   129  	}
   130  	if !foundSubDir {
   131  		t.Fatalf("ReadDir %s: exec directory not found", dirname)
   132  	}
   133  }
   134
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