mmap_test.go

     1  // Copyright 2025 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 mmap
     6  
     7  import (
     8  	"bytes"
     9  	"testing"
    10  )
    11  
    12  // TestMmap does a round trip to make sure the slice returned by
    13  // mmap contains the same data as was written to the file. It's
    14  // a test on one of the issues in #71059: on Windows we were
    15  // returning a slice containing all the data in the mmapped pages,
    16  // which could be longer than the file.
    17  func TestMmap(t *testing.T) {
    18  	// Use an already existing file as our test data. Avoid creating
    19  	// a temporary file so that we don't have to close the mapping on
    20  	// Windows before deleting the file during test cleanup.
    21  	f := "testdata/small_file.txt"
    22  
    23  	want := []byte("This file is shorter than 4096 bytes.\n")
    24  
    25  	data, _, err := Mmap(f)
    26  	if err != nil {
    27  		t.Fatalf("calling Mmap: %v", err)
    28  	}
    29  	if !bytes.Equal(data.Data, want) {
    30  		t.Fatalf("mmapped data slice: got %q; want %q", data.Data, want)
    31  	}
    32  }
    33
View as plain text