staging lines and hunks

2 files changed, 113 insertions, 0 deletions

diff --git a/pkg/utils/utils.go b/pkg/utils/utils.go
index 8e481b3a4..e2a5337e3 100644
--- a/pkg/utils/utils.go
+++ b/pkg/utils/utils.go
@@ -214,3 +214,24 @@ func IncludesString(list []string, a string) bool {
 	}
 	return false
 }
+
+// NextIndex returns the index of the element that comes after the given number
+func NextIndex(numbers []int, currentNumber int) int {
+	for index, number := range numbers {
+		if number > currentNumber {
+			return index
+		}
+	}
+	return 0
+}
+
+// PrevIndex returns the index that comes before the given number, cycling if we reach the end
+func PrevIndex(numbers []int, currentNumber int) int {
+	end := len(numbers) - 1
+	for i := end; i >= 0; i -= 1 {
+		if numbers[i] < currentNumber {
+			return i
+		}
+	}
+	return end
+}
diff --git a/pkg/utils/utils_test.go b/pkg/utils/utils_test.go
index 41774051b..f03bc087a 100644
--- a/pkg/utils/utils_test.go
+++ b/pkg/utils/utils_test.go
@@ -425,3 +425,95 @@ func TestIncludesString(t *testing.T) {
 		assert.EqualValues(t, s.expected, IncludesString(s.list, s.element))
 	}
 }
+
+func TestNextIndex(t *testing.T) {
+	type scenario struct {
+		testName string
+		list     []int
+		element  int
+		expected int
+	}
+
+	scenarios := []scenario{
+		{
+			// I'm not really fussed about how it behaves here
+			"no elements",
+			[]int{},
+			1,
+			0,
+		},
+		{
+			"one element",
+			[]int{1},
+			1,
+			0,
+		},
+		{
+			"two elements",
+			[]int{1, 2},
+			1,
+			1,
+		},
+		{
+			"two elements, giving second one",
+			[]int{1, 2},
+			2,
+			0,
+		},
+		{
+			"three elements, giving second one",
+			[]int{1, 2, 3},
+			2,
+			2,
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			assert.EqualValues(t, s.expected, NextIndex(s.list, s.element))
+		})
+	}
+}
+
+func TestPrevIndex(t *testing.T) {
+	type scenario struct {
+		testName string
+		list     []int
+		element  int
+		expected int
+	}
+
+	scenarios := []scenario{
+		{
+			// I'm not really fussed about how it behaves here
+			"no elements",
+			[]int{},
+			1,
+			-1,
+		},
+		{
+			"one element",
+			[]int{1},
+			1,
+			0,
+		},
+		{
+			"two elements",
+			[]int{1, 2},
+			1,
+			1,
+		},
+		{
+			"three elements, giving second one",
+			[]int{1, 2, 3},
+			2,
+			0,
+		},
+	}
+
+	for _, s := range scenarios {
+		t.Run(s.testName, func(t *testing.T) {
+			assert.EqualValues(t, s.expected, PrevIndex(s.list, s.element))
+		})
+	}
+}