diff --git a/nil_renderer_test.go b/nil_renderer_test.go
new file mode 100644
index 0000000..7364484
--- /dev/null
+++ b/nil_renderer_test.go
@@ -0,0 +1,16 @@
+package tea
+
+import "testing"
+
+func TestNilRenderer(t *testing.T) {
+	r := nilRenderer{}
+	r.start()
+	r.stop()
+	r.kill()
+	r.write("a")
+	r.repaint()
+	r.setAltScreen(true)
+	if r.altScreen() {
+		t.Errorf("altScreen should always return false")
+	}
+}
diff --git a/options_test.go b/options_test.go
new file mode 100644
index 0000000..4b75994
--- /dev/null
+++ b/options_test.go
@@ -0,0 +1,94 @@
+package tea
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestOptions(t *testing.T) {
+	t.Run("output", func(t *testing.T) {
+		var b bytes.Buffer
+		p := NewProgram(nil, WithOutput(&b))
+		if p.output != &b {
+			t.Errorf("expected output to custom, got %v", p.output)
+		}
+	})
+
+	t.Run("input", func(t *testing.T) {
+		var b bytes.Buffer
+		p := NewProgram(nil, WithInput(&b))
+		if p.input != &b {
+			t.Errorf("expected input to custom, got %v", p.output)
+		}
+		if p.startupOptions&withCustomInput == 0 {
+			t.Errorf("expected startup options to have custom input set, got %v", p.output)
+		}
+	})
+
+	t.Run("catch panics", func(t *testing.T) {
+		p := NewProgram(nil, WithoutCatchPanics())
+		if p.CatchPanics {
+			t.Errorf("catch panics should not have been set")
+		}
+	})
+
+	t.Run("renderer", func(t *testing.T) {
+		p := NewProgram(nil, WithoutRenderer())
+		switch p.renderer.(type) {
+		case *nilRenderer:
+			return
+		default:
+			t.Errorf("expected renderer to be a nilRenderer, got %v", p.renderer)
+		}
+	})
+
+	t.Run("startup options", func(t *testing.T) {
+		exercise := func(t *testing.T, opt ProgramOption, expect startupOptions) {
+			p := NewProgram(nil, opt)
+			if !p.startupOptions.has(expect) {
+				t.Errorf("expected startup options have %v, got %v", expect, p.startupOptions)
+			}
+		}
+
+		t.Run("input tty", func(t *testing.T) {
+			exercise(t, WithInputTTY(), withInputTTY)
+		})
+
+		t.Run("alt screen", func(t *testing.T) {
+			exercise(t, WithAltScreen(), withAltScreen)
+		})
+
+		t.Run("ansi compression", func(t *testing.T) {
+			exercise(t, WithANSICompressor(), withANSICompressor)
+		})
+
+		t.Run("mouse cell motion", func(t *testing.T) {
+			p := NewProgram(nil, WithMouseAllMotion(), WithMouseCellMotion())
+			if !p.startupOptions.has(withMouseCellMotion) {
+				t.Errorf("expected startup options have %v, got %v", withMouseCellMotion, p.startupOptions)
+			}
+			if p.startupOptions.has(withMouseAllMotion) {
+				t.Errorf("expected startup options not have %v, got %v", withMouseAllMotion, p.startupOptions)
+			}
+		})
+
+		t.Run("mouse all motion", func(t *testing.T) {
+			p := NewProgram(nil, WithMouseCellMotion(), WithMouseAllMotion())
+			if !p.startupOptions.has(withMouseAllMotion) {
+				t.Errorf("expected startup options have %v, got %v", withMouseAllMotion, p.startupOptions)
+			}
+			if p.startupOptions.has(withMouseCellMotion) {
+				t.Errorf("expected startup options not have %v, got %v", withMouseCellMotion, p.startupOptions)
+			}
+		})
+	})
+
+	t.Run("multiple", func(t *testing.T) {
+		p := NewProgram(nil, WithMouseAllMotion(), WithAltScreen(), WithInputTTY())
+		for _, opt := range []startupOptions{withMouseAllMotion, withAltScreen, withInputTTY} {
+			if !p.startupOptions.has(opt) {
+				t.Errorf("expected startup options have %v, got %v", opt, p.startupOptions)
+			}
+		}
+	})
+}
diff --git a/screen_test.go b/screen_test.go
new file mode 100644
index 0000000..7bfdf2e
--- /dev/null
+++ b/screen_test.go
@@ -0,0 +1,66 @@
+package tea
+
+import (
+	"bytes"
+	"io"
+	"testing"
+)
+
+func TestScreen(t *testing.T) {
+	exercise := func(t *testing.T, fn func(io.Writer), expect []byte) {
+		var w bytes.Buffer
+		fn(&w)
+		if !bytes.Equal(w.Bytes(), expect) {
+			t.Errorf("expected %q, got %q", expect, w.Bytes())
+		}
+	}
+
+	t.Run("change scrolling region", func(t *testing.T) {
+		exercise(t, func(w io.Writer) {
+			changeScrollingRegion(w, 16, 22)
+		}, []byte("\x1b[16;22r"))
+	})
+
+	t.Run("line", func(t *testing.T) {
+		t.Run("clear", func(t *testing.T) {
+			exercise(t, clearLine, []byte("\x1b[2K"))
+		})
+
+		t.Run("insert", func(t *testing.T) {
+			exercise(t, func(w io.Writer) {
+				insertLine(w, 12)
+			}, []byte("\x1b[12L"))
+		})
+	})
+
+	t.Run("cursor", func(t *testing.T) {
+		t.Run("hide", func(t *testing.T) {
+			exercise(t, hideCursor, []byte("\x1b[?25l"))
+		})
+
+		t.Run("show", func(t *testing.T) {
+			exercise(t, showCursor, []byte("\x1b[?25h"))
+		})
+
+		t.Run("up", func(t *testing.T) {
+			exercise(t, cursorUp, []byte("\x1b[1A"))
+		})
+
+		t.Run("down", func(t *testing.T) {
+			exercise(t, cursorDown, []byte("\x1b[1B"))
+		})
+
+		t.Run("move", func(t *testing.T) {
+			exercise(t, func(w io.Writer) {
+				moveCursor(w, 10, 20)
+			}, []byte("\x1b[10;20H"))
+		})
+
+		t.Run("back", func(t *testing.T) {
+			exercise(t, func(w io.Writer) {
+				cursorBack(w, 15)
+			}, []byte("\x1b[15D"))
+		})
+	})
+
+}