github.com/rigado/snapd@v2.42.5-go-mod+incompatible/osutil/cmp_test.go (about)

     1  // -*- Mode: Go; indent-tabs-mode: t -*-
     2  
     3  /*
     4   * Copyright (C) 2014-2015 Canonical Ltd
     5   *
     6   * This program is free software: you can redistribute it and/or modify
     7   * it under the terms of the GNU General Public License version 3 as
     8   * published by the Free Software Foundation.
     9   *
    10   * This program is distributed in the hope that it will be useful,
    11   * but WITHOUT ANY WARRANTY; without even the implied warranty of
    12   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    13   * GNU General Public License for more details.
    14   *
    15   * You should have received a copy of the GNU General Public License
    16   * along with this program.  If not, see <http://www.gnu.org/licenses/>.
    17   *
    18   */
    19  
    20  package osutil
    21  
    22  import (
    23  	"io/ioutil"
    24  	"os"
    25  	"path/filepath"
    26  	"strings"
    27  
    28  	. "gopkg.in/check.v1"
    29  )
    30  
    31  type CmpTestSuite struct{}
    32  
    33  var _ = Suite(&CmpTestSuite{})
    34  
    35  func (ts *CmpTestSuite) TestCmp(c *C) {
    36  	tmpdir := c.MkDir()
    37  
    38  	foo := filepath.Join(tmpdir, "foo")
    39  	f, err := os.Create(foo)
    40  	c.Assert(err, IsNil)
    41  	defer f.Close()
    42  
    43  	// pick a smaller bufsize so that the test can complete quicker
    44  	defer func() {
    45  		bufsz = defaultBufsz
    46  	}()
    47  	bufsz = 128
    48  
    49  	// test FilesAreEqual for various sizes:
    50  	// - bufsz not exceeded
    51  	// - bufsz matches file size
    52  	// - bufsz exceeds file size
    53  	canary := "1234567890123456"
    54  	for _, n := range []int{1, bufsz / len(canary), (bufsz / len(canary)) + 1} {
    55  		for i := 0; i < n; i++ {
    56  			c.Assert(FilesAreEqual(foo, foo), Equals, true)
    57  			_, err := f.WriteString(canary)
    58  			c.Assert(err, IsNil)
    59  			f.Sync()
    60  		}
    61  	}
    62  }
    63  
    64  func (ts *CmpTestSuite) TestCmpEmptyNeqMissing(c *C) {
    65  	tmpdir := c.MkDir()
    66  
    67  	foo := filepath.Join(tmpdir, "foo")
    68  	bar := filepath.Join(tmpdir, "bar")
    69  	f, err := os.Create(foo)
    70  	c.Assert(err, IsNil)
    71  	defer f.Close()
    72  	c.Assert(FilesAreEqual(foo, bar), Equals, false)
    73  	c.Assert(FilesAreEqual(bar, foo), Equals, false)
    74  }
    75  
    76  func (ts *CmpTestSuite) TestCmpEmptyNeqNonEmpty(c *C) {
    77  	tmpdir := c.MkDir()
    78  
    79  	foo := filepath.Join(tmpdir, "foo")
    80  	bar := filepath.Join(tmpdir, "bar")
    81  	f, err := os.Create(foo)
    82  	c.Assert(err, IsNil)
    83  	defer f.Close()
    84  	c.Assert(ioutil.WriteFile(bar, []byte("x"), 0644), IsNil)
    85  	c.Assert(FilesAreEqual(foo, bar), Equals, false)
    86  	c.Assert(FilesAreEqual(bar, foo), Equals, false)
    87  }
    88  
    89  func (ts *CmpTestSuite) TestCmpStreams(c *C) {
    90  	for _, x := range []struct {
    91  		a string
    92  		b string
    93  		r bool
    94  	}{
    95  		{"hello", "hello", true},
    96  		{"hello", "world", false},
    97  		{"hello", "hell", false},
    98  	} {
    99  		c.Assert(StreamsEqual(strings.NewReader(x.a), strings.NewReader(x.b)), Equals, x.r)
   100  	}
   101  }