os: improve Readdir test coverage, fix Readdir(0) on EOF

Adds tests for Readdir and Readdirnames with different n
values.  No good way to inject faults during full reads,
though.

Also fixes bug report from fshahriar:
Readdir(0) wasn't behaving like Readdir(-1).

R=rsc, fshahriar
CC=golang-dev
https://golang.org/cl/4529092

diff --git a/src/pkg/os/dir_unix.go b/src/pkg/os/dir_unix.go
index 9c543838e7115fb13f9baf109a2103ff8d1b7cf6..80ffda71df6ea1b440229ef769da6c65642b1975 100644 (file)
--- a/src/pkg/os/dir_unix.go
+++ b/src/pkg/os/dir_unix.go
@@ -32,7 +32,7 @@ func (f *File) Readdirnames(n int) (names []string, err Error) {
                f.dirinfo.buf = make([]byte, blockSize)
        }
        d := f.dirinfo
-       wantAll := n < 0
+       wantAll := n <= 0
 
        size := n
        if size < 0 {

diff --git a/src/pkg/os/os_test.go b/src/pkg/os/os_test.go
index 9a993cd6eda8bd3f3ca5eb2a6226067e6e3b4c17..d9535be6db068db69130ffe3684a5b2e27b99f51 100644 (file)
--- a/src/pkg/os/os_test.go
+++ b/src/pkg/os/os_test.go
@@ -286,6 +286,71 @@ func TestReaddirnamesOneAtATime(t *testing.T) {
        }
 }
 
+func TestReaddirNValues(t *testing.T) {
+       if testing.Short() {
+               t.Logf("test.short; skipping")
+               return
+       }
+       dir, err := ioutil.TempDir("", "")
+       if err != nil {
+               t.Fatalf("TempDir: %v", err)
+       }
+       defer RemoveAll(dir)
+       for i := 1; i <= 20; i++ {
+               f, err := Create(filepath.Join(dir, fmt.Sprintf("%d", i)))
+               if err != nil {
+                       t.Fatalf("Create: %v", err)
+               }
+               f.Write([]byte(strings.Repeat("X", i)))
+               f.Close()
+       }
+
+       var d *File
+       openDir := func() {
+               var err Error
+               d, err = Open(dir)
+               if err != nil {
+                       t.Fatalf("Open directory: %v", err)
+               }
+       }
+
+       readDirExpect := func(n, want int, wantErr Error) {
+               fi, err := d.Readdir(n)
+               if err != wantErr {
+                       t.Fatalf("Readdir of %d got error %v, want %v", n, err, wantErr)
+               }
+               if g, e := len(fi), want; g != e {
+                       t.Errorf("Readdir of %d got %d files, want %d", n, g, e)
+               }
+       }
+
+       readDirNamesExpect := func(n, want int, wantErr Error) {
+               fi, err := d.Readdirnames(n)
+               if err != wantErr {
+                       t.Fatalf("Readdirnames of %d got error %v, want %v", n, err, wantErr)
+               }
+               if g, e := len(fi), want; g != e {
+                       t.Errorf("Readdirnames of %d got %d files, want %d", n, g, e)
+               }
+       }
+
+       for _, fn := range []func(int, int, Error){readDirExpect, readDirNamesExpect} {
+               // Test the -1 case
+               openDir()
+               fn(-1, 20, nil)
+               fn(-2, 0, nil)
+               fn(0, 0, nil)
+               d.Close()
+
+               // Test the bounded case
+               openDir()
+               fn(19, 19, nil)
+               fn(18, 1, nil)
+               fn(17, 0, EOF)
+               d.Close()
+       }
+}
+
 func TestHardLink(t *testing.T) {
        // Hardlinks are not supported under windows.
        if syscall.OS == "windows" {