| 1 | package persistentshell |
| 2 | |
| 3 | import ( |
| 4 | "context" |
| 5 | "errors" |
| 6 | "fmt" |
| 7 | "io" |
| 8 | "strings" |
| 9 | "testing" |
| 10 | ) |
| 11 | |
| 12 | type stagingConn struct{ write func([]byte) (int, error) } |
| 13 | |
| 14 | func (c stagingConn) Read([]byte) (int, error) { return 0, io.EOF } |
| 15 | func (c stagingConn) Write(p []byte) (int, error) { return c.write(p) } |
| 16 | func (c stagingConn) Close() error { return nil } |
| 17 | |
| 18 | func TestCommandStagingConsumesSplitAcknowledgementBeforeNextWrite(t *testing.T) { |
| 19 | s := &session{pendingRead: make(chan readChunkResult, 4)} |
| 20 | writes, executed := 0, false |
| 21 | s.conn = stagingConn{write: func(p []byte) (int, error) { |
| 22 | if len(s.pendingRead) != 0 { |
| 23 | t.Fatal("advanced on echoed source or an earlier acknowledgement") |
| 24 | } |
| 25 | if strings.Contains(string(p), "; eval -- ") { |
| 26 | executed = true |
| 27 | return len(p), nil |
| 28 | } |
| 29 | ack := fmt.Sprintf("S_INPUT_%d", writes*commandWordLimit/4) |
| 30 | writes++ |
| 31 | s.pendingRead <- readChunkResult{data: p} |
| 32 | s.pendingRead <- readChunkResult{data: []byte("S_INPUT_OLD\n")} |
| 33 | s.pendingRead <- readChunkResult{data: []byte(ack[:3])} |
| 34 | s.pendingRead <- readChunkResult{data: []byte(ack[3:] + "\n")} |
| 35 | return len(p), nil |
| 36 | }} |
| 37 | if err := s.writeCommand(t.Context(), strings.Repeat("x", 4096), "S", "E:"); err != nil { |
| 38 | t.Fatal(err) |
| 39 | } |
| 40 | if writes != 32 || !executed { |
| 41 | t.Fatalf("stages=%d executed=%v", writes, executed) |
| 42 | } |
| 43 | } |
| 44 | |
| 45 | func TestCommandStagingCancellationDoesNotExecutePartialCommand(t *testing.T) { |
| 46 | ctx, cancel := context.WithCancel(t.Context()) |
| 47 | defer cancel() |
| 48 | s := &session{pendingRead: make(chan readChunkResult, 1)} |
| 49 | writes := 0 |
| 50 | s.conn = stagingConn{write: func(p []byte) (int, error) { |
| 51 | writes++ |
| 52 | if strings.Contains(string(p), "; eval -- ") { |
| 53 | t.Fatal("executed an unacknowledged command") |
| 54 | } |
| 55 | s.pendingRead <- readChunkResult{data: p} |
| 56 | cancel() |
| 57 | return len(p), nil |
| 58 | }} |
| 59 | if err := s.writeCommand(ctx, strings.Repeat("x", 4096), "S", "E:"); !errors.Is(err, context.Canceled) { |
| 60 | t.Fatalf("cancellation=%v", err) |
| 61 | } |
| 62 | if writes != 1 { |
| 63 | t.Fatalf("wrote %d stages after cancellation", writes) |
| 64 | } |
| 65 | } |
| 66 |