# frozen_string_literal: true

require "test_helper"

class TestMerge < Minitest::Test
  BASE = "one\ntwo\nthree\n"

  def test_a_backend_is_available
    assert Picopackage::Merge.available?, "expected git or diff3 on PATH"
  end

  def test_non_overlapping_changes_merge_cleanly
    result = Picopackage::Merge.three_way(
      base: BASE,
      ours: "ONE\ntwo\nthree\n",
      theirs: "one\ntwo\nTHREE\n"
    )

    assert_predicate result, :clean?
    assert_equal "ONE\ntwo\nTHREE\n", result.content
  end

  def test_identical_changes_on_both_sides_merge_cleanly
    changed = "one\nTWO\nthree\n"
    result = Picopackage::Merge.three_way(base: BASE, ours: changed, theirs: changed)

    assert_predicate result, :clean?
    assert_equal changed, result.content
  end

  def test_overlapping_changes_conflict
    result = Picopackage::Merge.three_way(
      base: BASE,
      ours: "one\nMINE\nthree\n",
      theirs: "one\nTHEIRS\nthree\n"
    )

    assert_predicate result, :conflict?
    assert_operator result.conflicts, :>, 0
    assert_includes result.content, "MINE"
    assert_includes result.content, "THEIRS"
    assert_includes result.content, "<<<<<<<"
  end

  def test_labels_appear_in_conflict_markers
    result = Picopackage::Merge.three_way(
      base: BASE,
      ours: "one\nMINE\nthree\n",
      theirs: "one\nTHEIRS\nthree\n"
    )

    assert_includes result.content, "local"
    assert_includes result.content, "upstream"
  end
end