fix(hashline-edit): add same-line operation precedence ordering

src/tools/hashline-edit/edit-operations.test.ts

@@ -92,6 +92,22 @@ describe("hashline edit operations", () => {
     expect(result).toEqual("line 1\ninserted\nline 2\nmodified")
   })
 
+  it("applies replace before prepend when both target same line", () => {
+    //#given
+    const content = "line 1\nline 2\nline 3"
+    const lines = content.split("\n")
+    const edits: HashlineEdit[] = [
+      { op: "prepend", pos: anchorFor(lines, 2), lines: "before line 2" },
+      { op: "replace", pos: anchorFor(lines, 2), lines: "modified line 2" },
+    ]
+
+    //#when
+    const result = applyHashlineEdits(content, edits)
+
+    //#then
+    expect(result).toEqual("line 1\nbefore line 2\nmodified line 2\nline 3")
+  })
+
   it("deduplicates identical insert edits in one pass", () => {
     //#given
     const content = "line 1\nline 2"

src/tools/hashline-edit/edit-operations.ts

@@ -27,7 +27,13 @@ export function applyHashlineEditsWithReport(content: string, edits: HashlineEdi
   }
 
   const dedupeResult = dedupeEdits(edits)
-  const sortedEdits = [...dedupeResult.edits].sort((a, b) => getEditLineNumber(b) - getEditLineNumber(a))
+  const EDIT_PRECEDENCE: Record<string, number> = { replace: 0, append: 1, prepend: 2 }
+  const sortedEdits = [...dedupeResult.edits].sort((a, b) => {
+    const lineA = getEditLineNumber(a)
+    const lineB = getEditLineNumber(b)
+    if (lineB !== lineA) return lineB - lineA
+    return (EDIT_PRECEDENCE[a.op] ?? 3) - (EDIT_PRECEDENCE[b.op] ?? 3)
+  })
 
   let noopEdits = 0
 
@@ -87,4 +93,3 @@ export function applyHashlineEditsWithReport(content: string, edits: HashlineEdi
 export function applyHashlineEdits(content: string, edits: HashlineEdit[]): string {
   return applyHashlineEditsWithReport(content, edits).content
 }
-