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