package linthost

import "testing"

// TestFixSelectTextEditsDropsDuplicateEdits verifies repeated edits collapse beside a disjoint edit.
//
// selectTextEdits keeps the source single-pass deterministic by deduping
// byte-identical edits before the overlap filter runs. This result assertion
// checks one surviving copy and the disjoint payload; it does not distinguish
// deduplication from overlap rejection or a position-only seen set.
//
//  1. Build three edits where the first two are byte-identical and the third
//     targets a disjoint range.
//  2. Run `selectTextEdits` against a synthetic source length.
//  3. Assert exactly two edits survive and both ranges are accounted for.
//
// @evidence contracts/testing.md#behavioral-verification selectTextEdits collapses a repeated let replacement and preserves the disjoint var replacement.
// @evidence contracts/testing.md#independent-expectations Exact supplied TextEdit identities independently require one repeated-range payload and the separate var range, rather than accepting any two survivors.
// @evidence contracts/testing.md#distinguishing-cases Duplicate identical edits collapse while a separate range survives; overlap rejection is owned by the companion case.
// @evidence contracts/testing.md#execution-ownership TestFixSelectTextEditsDropsDuplicateEdits calls selectTextEdits directly on its three-edit literal list.
func TestFixSelectTextEditsDropsDuplicateEdits(t *testing.T) {
  duplicate := TextEdit{Pos: 0, End: 3, Text: "let"}
  edits := []TextEdit{
    duplicate,
    duplicate,
    {Pos: 5, End: 8, Text: "var"},
  }
  selected := selectTextEdits(10, edits)
  if len(selected) != 2 {
    t.Fatalf("expected 2 surviving edits, got %d (%+v)", len(selected), selected)
  }
  if selected[0] != duplicate {
    t.Fatalf("expected first surviving edit to be the dedup'd entry, got %+v", selected[0])
  }
  if selected[1].Pos != 5 || selected[1].End != 8 || selected[1].Text != "var" {
    t.Fatalf("expected second surviving edit to be the disjoint entry, got %+v", selected[1])
  }
}