add: run video in pipe

internal/pipespy/pipespy_test.go

@@ -0,0 +1,115 @@
+package pipespy_test
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"sync"
+	"testing"
+
+	"github.com/chathaway-codes/home-sensors/v2/internal/pipespy"
+	"github.com/google/go-cmp/cmp"
+)
+
+func TestPipeSpy(t *testing.T) {
+	pipe := pipespy.New()
+
+	readPipe, writerPipe := io.Pipe()
+	stage1 := &simpleWriter{t: t, stdIn: readPipe}
+	stage2 := &simpleWriter{t: t}
+
+	stdOut1 := pipe.Add(stage1).Snoop()
+	stdOut2 := pipe.Add(stage2).Snoop()
+	pipe.Add(&simpleWriter{t: t})
+
+	// Spawn threads to keep reading the snoop
+	var buff1, buff2 []byte
+	var err1, err2 error
+	var wg sync.WaitGroup
+	wg.Add(2)
+	go func() {
+		defer wg.Done()
+		buff1, err1 = io.ReadAll(stdOut1)
+		if errors.Is(err1, io.EOF) {
+			err1 = nil
+		}
+	}()
+	go func() {
+		defer wg.Done()
+		buff2, err2 = io.ReadAll(stdOut2)
+		if errors.Is(err2, io.EOF) {
+			err2 = nil
+		}
+	}()
+
+	wait := pipe.Start()
+
+	msg := "This is a message!"
+	fmt.Fprint(writerPipe, msg)
+	if err := writerPipe.Close(); err != nil {
+		t.Fatalf("failed to close pipe: %v", err)
+	}
+
+	wait()
+	wg.Wait()
+
+	if err1 != nil || err2 != nil {
+		t.Errorf("Got errs %v and %v; want nil or EOF", err1, err2)
+	}
+
+	if diff := cmp.Diff(string(buff1), msg); diff != "" {
+		t.Errorf("got diff:\n%s", diff)
+	}
+	if diff := cmp.Diff(string(buff2), msg); diff != "" {
+		t.Errorf("got diff:\n%s", diff)
+	}
+}
+
+func TestPipeSpyError(t *testing.T) {
+	readPipe, writerPipe := io.Pipe()
+	pipe := pipespy.New()
+	pipe.Add(&simpleWriter{t: t, stdIn: readPipe})
+	pipe.Add(&simpleWriter{t: t, err: fmt.Errorf("this is an error")})
+	pipe.Add(&simpleWriter{t: t})
+
+	wait := pipe.Start()
+	if _, err := fmt.Fprintf(writerPipe, "Hello"); err != nil {
+		t.Fatalf("error: %v", err)
+	}
+	writerPipe.Close()
+
+	errs := wait()
+
+	if len(errs) != 1 {
+		t.Errorf("Expected 1 err; got %d", len(errs))
+	}
+}
+
+type simpleWriter struct {
+	stdIn   io.Reader
+	stdOut  io.Writer
+	gotData []byte
+	err     error
+	t       *testing.T
+}
+
+func (s *simpleWriter) SetStdin(r io.Reader) {
+	s.stdIn = r
+}
+
+func (s *simpleWriter) SetStdout(w io.Writer) {
+	s.stdOut = w
+}
+
+func (s *simpleWriter) Run() error {
+	if s.err != nil {
+		return s.err
+	}
+	bytes, err := io.ReadAll(s.stdIn)
+	if err != nil && !errors.Is(err, io.EOF) {
+		s.t.Errorf("Unexpected err: %v", err)
+	}
+	s.gotData = bytes
+	s.stdOut.Write(bytes)
+	return nil
+}