diff --git a/key_test.go b/key_test.go
new file mode 100644
index 0000000..ecb551c
--- /dev/null
+++ b/key_test.go
@@ -0,0 +1,73 @@
+package tea
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestKeyString(t *testing.T) {
+	t.Run("alt+space", func(t *testing.T) {
+		if got := KeyMsg(Key{
+			Type: keySP,
+			Alt:  true,
+		}).String(); got != "alt+space" {
+			t.Fatalf(`expected a "alt+space", got %q`, got)
+		}
+	})
+
+	t.Run("runes", func(t *testing.T) {
+		if got := KeyMsg(Key{
+			Type:  KeyRunes,
+			Runes: []rune{'a'},
+		}).String(); got != "a" {
+			t.Fatalf(`expected an "a", got %q`, got)
+		}
+	})
+
+	t.Run("invalid", func(t *testing.T) {
+		if got := KeyMsg(Key{
+			Type: KeyType(99999),
+		}).String(); got != "" {
+			t.Fatalf(`expected a "", got %q`, got)
+		}
+	})
+}
+
+func TestKeyTypeString(t *testing.T) {
+	t.Run("space", func(t *testing.T) {
+		if got := keySP.String(); got != "space" {
+			t.Fatalf(`expected a "space", got %q`, got)
+		}
+	})
+
+	t.Run("invalid", func(t *testing.T) {
+		if got := KeyType(99999).String(); got != "" {
+			t.Fatalf(`expected a "", got %q`, got)
+		}
+	})
+}
+
+func TestReadInput(t *testing.T) {
+	for out, in := range map[string][]byte{
+		"a":         {'a'},
+		"ctrl+a":    {byte(keySOH)},
+		"alt+a":     {0x1b, 'a'},
+		"abcd":      {'a', 'b', 'c', 'd'},
+		"up":        []byte("\x1b[A"),
+		"wheel up":  {'\x1b', '[', 'M', byte(32) + 0b0100_0000, byte(65), byte(49)},
+		"shift+tab": {'\x1b', '[', 'Z'},
+	} {
+		t.Run(out, func(t *testing.T) {
+			msg, err := readInput(bytes.NewReader(in))
+			if err != nil {
+				t.Fatalf("unexpected error: %v", err)
+			}
+			if m, ok := msg.(KeyMsg); ok && m.String() != out {
+				t.Fatalf(`expected a keymsg %q, got %q`, out, m)
+			}
+			if m, ok := msg.(MouseMsg); ok && mouseEventTypes[m.Type] != out {
+				t.Fatalf(`expected a mousemsg %q, got %q`, out, mouseEventTypes[m.Type])
+			}
+		})
+	}
+}