make combinedOutput actually output both stdout and stderr

Signed-off-by: Miguel Molina <miguel@erizocosmi.co>

Author: erizocosmico

internal/gps/_testdata/cmd/echosleep.go renamed to internal/gps/_testdata/cmd/echosleep/echosleep.go

@@ -0,0 +1,14 @@
+// Copyright 2017 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import (
+	"os"
+)
+
+func main() {
+	os.Stdout.WriteString("stdout")
+	os.Stderr.WriteString("stderr")
+}

internal/gps/_testdata/cmd/stdout_stderr/stdout_stderr.go

@@ -126,11 +126,11 @@ func (c *monitoredCmd) hasTimedOut() bool {
 }
 
 func (c *monitoredCmd) combinedOutput(ctx context.Context) ([]byte, error) {
+	c.cmd.Stderr = c.stdout
 	if err := c.run(ctx); err != nil {
-		return c.stderr.Bytes(), err
+		return c.stdout.Bytes(), err
 	}
 
-	// FIXME(sdboyer) this is not actually combined output
 	return c.stdout.Bytes(), nil
 }
 

internal/gps/cmd.go

@@ -9,6 +9,7 @@ import (
 	"fmt"
 	"os"
 	"os/exec"
+	"strings"
 	"testing"
 	"time"
 )
@@ -26,7 +27,7 @@ func TestMonitoredCmd(t *testing.T) {
 		t.Skip("skipping test with sleeps on short")
 	}
 
-	err := exec.Command("go", "build", "./_testdata/cmd/echosleep.go").Run()
+	err := exec.Command("go", "build", "./_testdata/cmd/echosleep/echosleep.go").Run()
 	if err != nil {
 		t.Errorf("Unable to build echosleep binary: %s", err)
 	}
@@ -89,3 +90,35 @@ func TestMonitoredCmd(t *testing.T) {
 		}
 	})
 }
+
+func TestCombinedOutput(t *testing.T) {
+	// Compile makes this a bit slow
+	if testing.Short() {
+		t.Skip("skipping test with compilation on short")
+	}
+
+	err := exec.Command("go", "build", "./_testdata/cmd/stdout_stderr/stdout_stderr.go").Run()
+	if err != nil {
+		t.Errorf("Unable to build stdout_stderr binary: %s", err)
+	}
+	defer os.Remove("./stdout_stderr")
+
+	cmd := newMonitoredCmd(
+		exec.Command("./stdout_stderr"),
+		490*time.Millisecond,
+	)
+
+	out, err := cmd.combinedOutput(context.Background())
+	if err != nil {
+		t.Errorf("Unexpected error: %s", err)
+	}
+
+	output := string(out)
+	if !strings.Contains(output, "stdout") {
+		t.Errorf("Expecting to receive output from stdout")
+	}
+
+	if !strings.Contains(output, "stderr") {
+		t.Errorf("Expecting to receive output from stderr")
+	}
+}