1 files changed, 112 insertions, 0 deletions
diff --git a/integrationtests/commandutils.go b/integrationtests/commandutils.go
new file mode 100644
index 0000000..d2f567f
--- /dev/null
+++ b/integrationtests/commandutils.go
@@ -0,0 +1,112 @@
+package integrationtests
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"os"
+	"os/exec"
+	"sync"
+	"syscall"
+	"time"
+)
+
+// The exit code and the Go error of the command terminated.
+type exitPromise func() (int, error)
+
+func runCommand(ctx context.Context, stdoutFile, cmdStr string,
+	args ...string) (int, error) {
+
+	stdinCh, _, exit, err := startCommand(ctx, cmdStr, args...)
+	if err != nil {
+		return -1, err
+	}
+
+	fd, err := os.Create(stdoutFile)
+	if err != nil {
+		return -2, err
+	}
+
+	var wg sync.WaitGroup
+	wg.Add(1)
+	defer wg.Wait()
+
+	go func() {
+		defer fd.Close()
+		defer wg.Done()
+		for line := range stdinCh {
+			fd.WriteString(line)
+			fd.WriteString("\n")
+		}
+	}()
+
+	return exit()
+}
+
+func runCommandRetry(ctx context.Context, retries int, stdoutFile, cmd string,
+	args ...string) (exitCode int, err error) {
+
+	for i := 0; i < retries; i++ {
+		time.Sleep(time.Second)
+		if exitCode, err = runCommand(ctx, stdoutFile, cmd, args...); exitCode == 0 {
+			return
+		}
+	}
+	return
+}
+
+func startCommand(ctx context.Context, cmdStr string,
+	args ...string) (<-chan string, <-chan string, exitPromise, error) {
+
+	stdoutCh := make(chan string)
+	stderrCh := make(chan string)
+
+	if _, err := os.Stat(cmdStr); err != nil {
+		return stdoutCh, stderrCh, nil,
+			fmt.Errorf("no such executable '%s', please compile first: %v", cmdStr, err)
+	}
+
+	cmd := exec.CommandContext(ctx, cmdStr, args...)
+
+	cmdStdout, err := cmd.StdoutPipe()
+	if err != nil {
+		return stdoutCh, stderrCh, nil, err
+	}
+	cmdStderr, err := cmd.StderrPipe()
+	err = cmd.Start()
+	if err != nil {
+		return stdoutCh, stderrCh, nil, err
+	}
+
+	go func() {
+		defer close(stdoutCh)
+		scanner := bufio.NewScanner(cmdStdout)
+		scanner.Split(bufio.ScanLines)
+		for scanner.Scan() {
+			stdoutCh <- scanner.Text()
+		}
+	}()
+	go func() {
+		close(stderrCh)
+		scanner := bufio.NewScanner(cmdStderr)
+		scanner.Split(bufio.ScanLines)
+		for scanner.Scan() {
+			stderrCh <- scanner.Text()
+		}
+	}()
+
+	return stdoutCh, stderrCh, func() (int, error) {
+		err := cmd.Wait()
+		return exitCodeFromError(err), err
+	}, nil
+}
+
+func exitCodeFromError(err error) int {
+	if err != nil {
+		if exitError, ok := err.(*exec.ExitError); ok {
+			ws := exitError.Sys().(syscall.WaitStatus)
+			return ws.ExitStatus()
+		}
+	}
+	return 0
+}