feat(test): add test for JoinHorizontal (#346)

* refactor: use position constants

* test: add test for JoinHorizontal

join_test.go

@@ -9,8 +9,8 @@ func TestJoinVertical(t *testing.T) {
 		expected string
 	}
 	tests := []test{
-		{"pos0", JoinVertical(0, "A", "BBBB"), "A   \nBBBB"},
-		{"pos1", JoinVertical(1, "A", "BBBB"), "   A\nBBBB"},
+		{"pos0", JoinVertical(Left, "A", "BBBB"), "A   \nBBBB"},
+		{"pos1", JoinVertical(Right, "A", "BBBB"), "   A\nBBBB"},
 		{"pos0.25", JoinVertical(0.25, "A", "BBBB"), " A  \nBBBB"},
 	}
 
@@ -22,3 +22,24 @@ func TestJoinVertical(t *testing.T) {
 		})
 	}
 }
+
+func TestJoinHorizontal(t *testing.T) {
+	type test struct {
+		name     string
+		result   string
+		expected string
+	}
+	tests := []test{
+		{"pos0", JoinHorizontal(Top, "A", "B\nB\nB\nB"), "AB\n B\n B\n B"},
+		{"pos1", JoinHorizontal(Bottom, "A", "B\nB\nB\nB"), " B\n B\n B\nAB"},
+		{"pos0.25", JoinHorizontal(0.25, "A", "B\nB\nB\nB"), " B\nAB\n B\n B"},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			if test.result != test.expected {
+				t.Errorf("Got \n%s\n, expected \n%s\n", test.result, test.expected)
+			}
+		})
+	}
+}