diff --git a/cmdext/cmdrunner_test.go b/cmdext/cmdrunner_test.go
index e4f2327..2deac37 100644
--- a/cmdext/cmdrunner_test.go
+++ b/cmdext/cmdrunner_test.go
@@ -84,3 +84,115 @@ func TestPartialRead(t *testing.T) {
 	}
 
 }
+
+func TestPartialReadStderr(t *testing.T) {
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", file=sys.stderr, flush=True); time.sleep(5); print(\"cant see me\", file=sys.stderr, flush=True);").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "first message\n" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestReadUnflushedStdout(t *testing.T) {
+
+	res1, err := Runner("python").Arg("-c").Arg("import sys; print(\"message101\", file=sys.stdout, end='')").Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "message101" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "message101\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestReadUnflushedStderr(t *testing.T) {
+
+	res1, err := Runner("python").Arg("-c").Arg("import sys; print(\"message101\", file=sys.stderr, end='')").Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if res1.StdErr != "message101" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "message101\n" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestPartialReadUnflushed(t *testing.T) {
+	t.SkipNow()
+
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", end=''); time.sleep(5); print(\"cant see me\", end='');").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "first message" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}
+
+func TestPartialReadUnflushedStderr(t *testing.T) {
+	t.SkipNow()
+
+	res1, err := Runner("python").
+		Arg("-c").
+		Arg("import sys; import time; print(\"first message\", file=sys.stderr, end=''); time.sleep(5); print(\"cant see me\", file=sys.stderr, end='');").
+		Timeout(100 * time.Millisecond).
+		Run()
+	if err != nil {
+		t.Errorf("%v", err)
+	}
+	if !res1.CommandTimedOut {
+		t.Errorf("!CommandTimedOut")
+	}
+	if res1.StdErr != "first message" {
+		t.Errorf("res1.StdErr == '%v'", res1.StdErr)
+	}
+	if res1.StdOut != "" {
+		t.Errorf("res1.StdOut == '%v'", res1.StdOut)
+	}
+	if res1.StdCombined != "first message" {
+		t.Errorf("res1.StdCombined == '%v'", res1.StdCombined)
+	}
+
+}