Checkpoint on insert and search/replace tools

src/core/diff/insert-groups.ts

@@ -0,0 +1,31 @@
+/**
+ * Inserts multiple groups of elements at specified indices in an array
+ * @param original Array to insert into, split by lines
+ * @param insertGroups Array of groups to insert, each with an index and elements to insert
+ * @returns New array with all insertions applied
+ */
+export interface InsertGroup {
+	index: number
+	elements: string[]
+}
+
+export function insertGroups(original: string[], insertGroups: InsertGroup[]): string[] {
+	// Sort groups by index to maintain order
+	insertGroups.sort((a, b) => a.index - b.index)
+
+	let result: string[] = []
+	let lastIndex = 0
+
+	insertGroups.forEach(({ index, elements }) => {
+		// Add elements from original array up to insertion point
+		result.push(...original.slice(lastIndex, index))
+		// Add the group of elements
+		result.push(...elements)
+		lastIndex = index
+	})
+
+	// Add remaining elements from original array
+	result.push(...original.slice(lastIndex))
+
+	return result
+}