package pendingattach

import "testing"

func TestDedupe_CollapsesByFileID(t *testing.T) {
	rows := []Attachment{
		{ID: "1", FileID: "a", Ord: 0},
		{ID: "2", FileID: "b", Ord: 1},
		{ID: "3", FileID: "a", Ord: 2}, // dup of file a
	}
	out := Dedupe(rows)
	if len(out) != 2 {
		t.Fatalf("want 2 rows, got %d: %+v", len(out), out)
	}
	if out[0].ID != "1" || out[1].ID != "2" {
		t.Fatalf("first-wins order not preserved: %+v", out)
	}
}

func TestDedupe_EmptyFileIDNeverCollapsed(t *testing.T) {
	rows := []Attachment{
		{ID: "1", FileID: ""},
		{ID: "2", FileID: ""},
	}
	if got := Dedupe(rows); len(got) != 2 {
		t.Fatalf("empty FileID rows must not collapse, got %d", len(got))
	}
}

func TestDedupe_ShortInputPassthrough(t *testing.T) {
	rows := []Attachment{{ID: "1", FileID: "a"}}
	if got := Dedupe(rows); len(got) != 1 {
		t.Fatalf("single row should pass through, got %d", len(got))
	}
}