github.com/reds/docker@v1.11.2-rc1/pkg/tailfile/tailfile_test.go (about)

     1  package tailfile
     2  
     3  import (
     4  	"io/ioutil"
     5  	"os"
     6  	"testing"
     7  )
     8  
     9  func TestTailFile(t *testing.T) {
    10  	f, err := ioutil.TempFile("", "tail-test")
    11  	if err != nil {
    12  		t.Fatal(err)
    13  	}
    14  	defer f.Close()
    15  	defer os.RemoveAll(f.Name())
    16  	testFile := []byte(`first line
    17  second line
    18  third line
    19  fourth line
    20  fifth line
    21  next first line
    22  next second line
    23  next third line
    24  next fourth line
    25  next fifth line
    26  last first line
    27  next first line
    28  next second line
    29  next third line
    30  next fourth line
    31  next fifth line
    32  next first line
    33  next second line
    34  next third line
    35  next fourth line
    36  next fifth line
    37  last second line
    38  last third line
    39  last fourth line
    40  last fifth line
    41  truncated line`)
    42  	if _, err := f.Write(testFile); err != nil {
    43  		t.Fatal(err)
    44  	}
    45  	if _, err := f.Seek(0, os.SEEK_SET); err != nil {
    46  		t.Fatal(err)
    47  	}
    48  	expected := []string{"last fourth line", "last fifth line"}
    49  	res, err := TailFile(f, 2)
    50  	if err != nil {
    51  		t.Fatal(err)
    52  	}
    53  	for i, l := range res {
    54  		t.Logf("%s", l)
    55  		if expected[i] != string(l) {
    56  			t.Fatalf("Expected line %s, got %s", expected[i], l)
    57  		}
    58  	}
    59  }
    60  
    61  func TestTailFileManyLines(t *testing.T) {
    62  	f, err := ioutil.TempFile("", "tail-test")
    63  	if err != nil {
    64  		t.Fatal(err)
    65  	}
    66  	defer f.Close()
    67  	defer os.RemoveAll(f.Name())
    68  	testFile := []byte(`first line
    69  second line
    70  truncated line`)
    71  	if _, err := f.Write(testFile); err != nil {
    72  		t.Fatal(err)
    73  	}
    74  	if _, err := f.Seek(0, os.SEEK_SET); err != nil {
    75  		t.Fatal(err)
    76  	}
    77  	expected := []string{"first line", "second line"}
    78  	res, err := TailFile(f, 10000)
    79  	if err != nil {
    80  		t.Fatal(err)
    81  	}
    82  	for i, l := range res {
    83  		t.Logf("%s", l)
    84  		if expected[i] != string(l) {
    85  			t.Fatalf("Expected line %s, got %s", expected[i], l)
    86  		}
    87  	}
    88  }
    89  
    90  func TestTailEmptyFile(t *testing.T) {
    91  	f, err := ioutil.TempFile("", "tail-test")
    92  	if err != nil {
    93  		t.Fatal(err)
    94  	}
    95  	defer f.Close()
    96  	defer os.RemoveAll(f.Name())
    97  	res, err := TailFile(f, 10000)
    98  	if err != nil {
    99  		t.Fatal(err)
   100  	}
   101  	if len(res) != 0 {
   102  		t.Fatal("Must be empty slice from empty file")
   103  	}
   104  }
   105  
   106  func TestTailNegativeN(t *testing.T) {
   107  	f, err := ioutil.TempFile("", "tail-test")
   108  	if err != nil {
   109  		t.Fatal(err)
   110  	}
   111  	defer f.Close()
   112  	defer os.RemoveAll(f.Name())
   113  	testFile := []byte(`first line
   114  second line
   115  truncated line`)
   116  	if _, err := f.Write(testFile); err != nil {
   117  		t.Fatal(err)
   118  	}
   119  	if _, err := f.Seek(0, os.SEEK_SET); err != nil {
   120  		t.Fatal(err)
   121  	}
   122  	if _, err := TailFile(f, -1); err != ErrNonPositiveLinesNumber {
   123  		t.Fatalf("Expected ErrNonPositiveLinesNumber, got %s", err)
   124  	}
   125  	if _, err := TailFile(f, 0); err != ErrNonPositiveLinesNumber {
   126  		t.Fatalf("Expected ErrNonPositiveLinesNumber, got %s", err)
   127  	}
   128  }
   129  
   130  func BenchmarkTail(b *testing.B) {
   131  	f, err := ioutil.TempFile("", "tail-test")
   132  	if err != nil {
   133  		b.Fatal(err)
   134  	}
   135  	defer f.Close()
   136  	defer os.RemoveAll(f.Name())
   137  	for i := 0; i < 10000; i++ {
   138  		if _, err := f.Write([]byte("tailfile pretty interesting line\n")); err != nil {
   139  			b.Fatal(err)
   140  		}
   141  	}
   142  	b.ResetTimer()
   143  	for i := 0; i < b.N; i++ {
   144  		if _, err := TailFile(f, 1000); err != nil {
   145  			b.Fatal(err)
   146  		}
   147  	}
   148  }