internal/app/sppulse: check buf error injection

The loadFile behaviour does not guarantee the buffer to be zeroed or not clobbered if an error is returned, but for the current implementation it is good to check.

Signed-off-by: Ophestra <cat@gensokyo.uk>

1 files changed, 41 insertions, 58 deletions

diff --git a/internal/app/sppulse_test.go b/internal/app/sppulse_test.go
index 7c050bf5..6940f227 100644
--- a/internal/app/sppulse_test.go
+++ b/internal/app/sppulse_test.go
@@ -244,6 +244,40 @@ func TestSpPulseOp(t *testing.T) {
 func TestLoadFile(t *testing.T) {
 	t.Parallel()
 
+	fAfterWriteExact := func(k *kstub) error {
+		buf := make([]byte, 1<<8)
+		n, err := loadFile(k, k,
+			"simulated PulseAudio cookie",
+			"/home/ophestra/xdg/config/pulse/cookie",
+			buf)
+		k.Verbose(buf[:n])
+		return err
+	}
+
+	fAfterWrite := func(k *kstub) error {
+		buf := make([]byte, 1<<8+0xfd)
+		n, err := loadFile(k, k,
+			"simulated PulseAudio cookie",
+			"/home/ophestra/xdg/config/pulse/cookie",
+			buf)
+		k.Verbose(buf[:n])
+		return err
+	}
+
+	fBeforeWrite := func(k *kstub) error {
+		buf := make([]byte, 1<<8+0xfd)
+		n, err := loadFile(k, k,
+			"simulated PulseAudio cookie",
+			"/home/ophestra/xdg/config/pulse/cookie",
+			buf)
+		k.Verbose(n)
+
+		if !bytes.Equal(buf, make([]byte, len(buf))) {
+			t.Errorf("loadFile: buf = %#v", buf)
+		}
+		return err
+	}
+
 	sampleCookie := bytes.Repeat([]byte{0xfc}, pulseCookieSizeMax)
 	checkSimple(t, "loadFile", []simpleTestCase{
 		{"buf", func(k *kstub) error {
@@ -257,14 +291,7 @@ func TestLoadFile(t *testing.T) {
 			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
 		}}, errors.New("invalid buffer")},
 
-		{"stat", func(k *kstub) error {
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				make([]byte, 1<<8+0xfd))
-			k.Verbose(n)
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"stat", fBeforeWrite, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, (*stubFi)(nil), stub.UniqueError(3)),
 			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
 		}}, &hst.AppError{
@@ -272,14 +299,7 @@ func TestLoadFile(t *testing.T) {
 			Err:  stub.UniqueError(3),
 		}},
 
-		{"dir", func(k *kstub) error {
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				make([]byte, 1<<8+0xfd))
-			k.Verbose(n)
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"dir", fBeforeWrite, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{isDir: true}, nil),
 			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
 		}}, &hst.AppError{
@@ -287,14 +307,7 @@ func TestLoadFile(t *testing.T) {
 			Err:  &os.PathError{Op: "stat", Path: "/home/ophestra/xdg/config/pulse/cookie", Err: syscall.EISDIR},
 		}},
 
-		{"oob", func(k *kstub) error {
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				make([]byte, 1<<8+0xfd))
-			k.Verbose(n)
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"oob", fBeforeWrite, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1<<8 + 0xff}, nil),
 			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
 		}}, &hst.AppError{
@@ -303,58 +316,28 @@ func TestLoadFile(t *testing.T) {
 			Msg:  `simulated PulseAudio cookie at "/home/ophestra/xdg/config/pulse/cookie" exceeds expected size`,
 		}},
 
-		{"open", func(k *kstub) error {
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				make([]byte, 1<<8+0xfd))
-			k.Verbose(n)
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"open", fBeforeWrite, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
 			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
 			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, (*stubOsFile)(nil), stub.UniqueError(2)),
 			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
 		}}, &hst.AppError{Step: "open simulated PulseAudio cookie", Err: stub.UniqueError(2)}},
 
-		{"read", func(k *kstub) error {
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				make([]byte, 1<<8+0xfd))
-			k.Verbose(n)
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"read", fBeforeWrite, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
 			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
 			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{Reader: errorReader{stub.UniqueError(1)}}, nil),
 			call("verbose", stub.ExpectArgs{[]any{-1}}, nil, nil),
 		}}, &hst.AppError{Step: "read simulated PulseAudio cookie", Err: stub.UniqueError(1)}},
 
-		{"short close", func(k *kstub) error {
-			buf := make([]byte, 1<<8+0xfd)
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				buf)
-			k.Verbose(buf[:n])
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"short close", fAfterWrite, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
 			call("verbosef", stub.ExpectArgs{"%s at %q is %d bytes shorter than expected", []any{"simulated PulseAudio cookie", "/home/ophestra/xdg/config/pulse/cookie", int64(0xfd)}}, nil, nil),
 			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{closeErr: stub.UniqueError(0), Reader: bytes.NewReader(sampleCookie)}, nil),
 			call("verbose", stub.ExpectArgs{[]any{sampleCookie}}, nil, nil),
 		}}, &hst.AppError{Step: "close simulated PulseAudio cookie", Err: stub.UniqueError(0)}},
 
-		{"success", func(k *kstub) error {
-			buf := make([]byte, 1<<8)
-			n, err := loadFile(k, k,
-				"simulated PulseAudio cookie",
-				"/home/ophestra/xdg/config/pulse/cookie",
-				buf)
-			k.Verbose(buf[:n])
-			return err
-		}, stub.Expect{Calls: []stub.Call{
+		{"success", fAfterWriteExact, stub.Expect{Calls: []stub.Call{
 			call("stat", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubFi{size: 1 << 8}, nil),
 			call("verbosef", stub.ExpectArgs{"loading %d bytes from %q", []any{1 << 8, "/home/ophestra/xdg/config/pulse/cookie"}}, nil, nil),
 			call("open", stub.ExpectArgs{"/home/ophestra/xdg/config/pulse/cookie"}, &stubOsFile{Reader: bytes.NewReader(sampleCookie)}, nil),