github.com/bazelbuild/remote-apis-sdks@v0.0.0-20240425170053-8a36686a6350/go/pkg/outerr/outerr_test.go (about)

     1  package outerr
     2  
     3  import (
     4  	"bytes"
     5  	"fmt"
     6  	"io"
     7  	"os"
     8  	"testing"
     9  )
    10  
    11  func TestRecordingOutErr(t *testing.T) {
    12  	t.Parallel()
    13  	o := NewRecordingOutErr()
    14  	o.WriteOut([]byte("hello"))
    15  	o.WriteErr([]byte("world"))
    16  	gotOut := o.Stdout()
    17  	if !bytes.Equal(gotOut, []byte("hello")) {
    18  		t.Errorf("expected o.Stdout() to return hello, got %v", gotOut)
    19  	}
    20  	gotErr := o.Stderr()
    21  	if !bytes.Equal(gotErr, []byte("world")) {
    22  		t.Errorf("expected o.Stderr() to return hello, got %v", gotErr)
    23  	}
    24  }
    25  
    26  func TestSystemOutErr(t *testing.T) {
    27  	// Capture the actual system stdout/stderr.
    28  	r, w, err := os.Pipe()
    29  	if err != nil {
    30  		t.Fatalf("error calling os.Pipe() = %v", err)
    31  	}
    32  
    33  	stdout := os.Stdout
    34  	fmt.Printf("capturing stdout to %v\n", w)
    35  	os.Stdout = w
    36  	defer func() {
    37  		fmt.Printf("resetting stdout to %v", stdout)
    38  		os.Stdout = stdout
    39  	}()
    40  
    41  	stderr := os.Stderr
    42  	os.Stderr = w
    43  	defer func() {
    44  		os.Stderr = stderr
    45  	}()
    46  
    47  	// We have to replicate the construction in the test instead of using SystemOutErr directly.
    48  	systemOutErr := NewStreamOutErr(os.Stdout, os.Stderr)
    49  	systemOutErr.WriteOut([]byte("hello "))
    50  	systemOutErr.WriteErr([]byte("world"))
    51  
    52  	w.Close()
    53  
    54  	var buf bytes.Buffer
    55  	io.Copy(&buf, r)
    56  
    57  	if buf.String() != "hello world" {
    58  		t.Errorf("expected stdout+stderr to equal \"hello world\", got %v", buf.String())
    59  	}
    60  }
    61  
    62  func TestWriters(t *testing.T) {
    63  	t.Parallel()
    64  	oe := NewRecordingOutErr()
    65  	o, e := NewOutWriter(oe), NewErrWriter(oe)
    66  	if n, err := o.Write([]byte("hello")); n != 5 || err != nil {
    67  		t.Errorf("expected o.Write(\"hello\") to return 5, nil; got %d, %v", n, err)
    68  	}
    69  	if n, err := e.Write([]byte("world")); n != 5 || err != nil {
    70  		t.Errorf("expected e.Write(\"world\") to return 5, nil; got %d, %v", n, err)
    71  	}
    72  	if got := oe.Stdout(); !bytes.Equal(got, []byte("hello")) {
    73  		t.Errorf("expected oe.Stdout() to return hello, got %v", got)
    74  	}
    75  	if got := oe.Stderr(); !bytes.Equal(got, []byte("world")) {
    76  		t.Errorf("expected oe.Stderr() to return world, got %v", got)
    77  	}
    78  }