diff --git a/api/runner/func_logger_test.go b/api/runner/func_logger_test.go
new file mode 100644
index 000000000..ed9c8858b
--- /dev/null
+++ b/api/runner/func_logger_test.go
@@ -0,0 +1,76 @@
+package runner
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+type nopCloser struct {
+	io.Writer
+}
+
+func (n nopCloser) Close() error { return nil }
+
+func TestLimitWriter(t *testing.T) {
+	var b bytes.Buffer
+	const max = 5
+	lw := newLimitWriter(max, nopCloser{&b})
+
+	lw.Write([]byte("yo"))
+
+	if b.Len() != 2 {
+		t.Fatal("expected 2 bytes in buffer, got:", b.Len())
+	}
+
+	n, _ := lw.Write([]byte("dawg"))
+
+	// can't check b.Len() really since the overage message is written in
+	if n != 3 {
+		t.Fatalf("limit writer allowed writing over the limit or n was wrong. n: %d", n)
+	}
+
+	n, err := lw.Write([]byte("yodawg"))
+
+	if n != 0 || err == nil {
+		t.Fatalf("limit writer wrote after limit exceeded, n > 0 or err is nil. n: %d err: %v", n, err)
+	}
+
+	// yes should const this. yes i'm wrong. yes you're wrong. no it doesn't matter.
+	if !bytes.HasPrefix(b.Bytes(), []byte("yodaw\n-----max")) {
+		t.Fatal("expected buffer to be 'yodawg', got:", b.String())
+	}
+}
+
+func TestLineWriter(t *testing.T) {
+	var b bytes.Buffer
+	lw := newLineWriter(&b)
+
+	lw.Write([]byte("yo"))
+
+	if b.Len() != 0 {
+		t.Fatal("expected no bytes to be written, got bytes")
+	}
+
+	lw.Write([]byte("\ndawg"))
+
+	if b.Len() != 3 {
+		t.Fatal("expected 3 bytes to be written in, got:", b.Len())
+	}
+
+	lw.Write([]byte("\ndawgy\ndawg"))
+
+	if b.Len() != 14 {
+		t.Fatal("expected 14 bytes to be written in, got:", b.Len())
+	}
+
+	lw.Close()
+
+	if b.Len() != 19 {
+		t.Fatal("expected 19 bytes to be written in, got:", b.Len())
+	}
+
+	if !bytes.HasSuffix(b.Bytes(), []byte("\n")) {
+		t.Fatal("line writer close is broked, expected new line")
+	}
+}