1 files changed, 54 insertions, 0 deletions
diff --git a/viewport/viewport_test.go b/viewport/viewport_test.go
new file mode 100644
index 0000000..9da4c3c
--- /dev/null
+++ b/viewport/viewport_test.go
@@ -0,0 +1,54 @@
+//go:build test
+
+package viewport
+
+import (
+	"github.com/stretchr/testify/assert"
+	"strings"
+	"testing"
+)
+
+func TestCrop(t *testing.T) {
+	input := `0000
+AAAA
+` + Caret + `BBB
+CCC`
+	expected := `AAAA
+` + Caret + `BBB`
+	result, _, _ := Crop(input, strings.Split(input, "\n"), 2)
+	assert.Equal(t, expected, result)
+}
+
+func TestCrop_Under(t *testing.T) {
+	input := `0000
+AAAA
+` + Caret + `BBB`
+	expected := `AAAA
+` + Caret + `BBB`
+	result, _, _ := Crop(input, strings.Split(input, "\n"), 2)
+	assert.Equal(t, expected, result)
+}
+
+func TestCrop_Unnecessary(t *testing.T) {
+	input := `AAAA
+` + Caret + `BBB
+CCC
+DDDD`
+	expected := input
+	result, _, _ := Crop(input, strings.Split(input, "\n"), 8)
+	assert.Equal(t, expected, result)
+}
+
+func TestNeedsViewport(t *testing.T) {
+	amount := 3
+	input := strings.Repeat("\n", amount)
+	output := NeedsViewport(input, 4)
+	assert.Equal(t, false, output)
+}
+
+func TestNeedsViewport_Negative(t *testing.T) {
+	amount := 8
+	input := strings.Repeat("\n", amount)
+	output := NeedsViewport(input, 4)
+	assert.Equal(t, true, output)
+}