diff --git a/day-3/one_test.go b/day-3/one_test.go
index 97265cc..9405c37 100644
--- a/day-3/one_test.go
+++ b/day-3/one_test.go
@@ -34,4 +34,71 @@ func TestSymbolToBool(t *testing.T) {
 
 func TestCheckDigit(t *testing.T) {
 	//t.Skip("skipping test")
+	symbols := [][]bool{
+		{false, false, false, false, false, false, false, false, false, false},
+		{false, false, false, true, false, false, false, false, false, false},
+		{false, false, false, false, false, false, false, false, false, false},
+		{false, false, false, false, false, false, true, false, false, false},
+	}
+
+	d1 := func() digit {
+		var d digit = digit{row: 0, col: 2, raw: 0, pass: false}
+		i := d.col - 1
+		for ; i < len(symbols[d.row]) && i <= d.col+1; i += 1 {
+			if i < 0 {
+				continue
+			}
+			if d.row != 0 {
+				if symbols[d.row-1][i] {
+					d.pass = true
+					break
+				}
+			}
+			if symbols[d.row][i] {
+				d.pass = true
+				break
+			}
+			if d.row != len(symbols)-1 {
+				if symbols[d.row+1][i] {
+					d.pass = true
+					break
+				}
+			}
+		}
+		return d
+	}()
+	d2 := func() digit {
+		var d digit = digit{row: 2, col: 9, raw: 0, pass: false}
+		i := d.col - 1
+		for ; i < len(symbols[d.row]) && i <= d.col+1; i += 1 {
+			if i < 0 {
+				continue
+			}
+			if d.row != 0 {
+				if symbols[d.row-1][i] {
+					d.pass = true
+					break
+				}
+			}
+			if symbols[d.row][i] {
+				d.pass = true
+				break
+			}
+			if d.row != len(symbols)-1 {
+				if symbols[d.row+1][i] {
+					d.pass = true
+					break
+				}
+			}
+		}
+		return d
+	}()
+
+	t.Run("Should pass the check", func(t *testing.T) {
+		assert.Equal(t, true, d1.pass)
+	})
+
+	t.Run("Should fail the check", func(t *testing.T) {
+		assert.Equal(t, false, d2.pass)
+	})
 }