# FrontierLab checked API examples

This file is executed by `moon check` and `moon test`. The human-facing guide remains in `README.md`.

```mbt check
///|
test "build encode and decode a trace" {
  let scene = @frontierlab.Scene::new(objects=[
    @frontierlab.Sequence(
      @frontierlab.SequenceState::new(id="values", label="Values", items=[
        @frontierlab.SequenceItem::new(id="a", value="2"),
        @frontierlab.SequenceItem::new(id="b", value="1"),
      ]),
    ),
  ])
  let builder = @frontierlab.TraceBuilder::new(
    title="Checked example",
    algorithm="example",
    initial_scene=scene,
  )
  builder.record(
    event=@frontierlab.Compare([
      @frontierlab.TargetRef::entity("values", "a"),
      @frontierlab.TargetRef::entity("values", "b"),
    ]),
    scene~,
  )
  let trace = builder.finish()
  let decoded = @frontierlab.AlgorithmTrace::decode_json(trace.encode_json())
  assert_true(decoded == trace)
}
```

```mbt check
///|
test "generate an offline trace playground" {
  let html = @frontierlab.render_trace_playground()
  assert_true(html.contains("AI Trace Clinic"))
  assert_true(!html.contains("<script src="))
  let player = @frontierlab.render_trace_html(
    @frontierlab.insertion_sort_trace([3, 1, 2]),
  )
  assert_true(player.contains("id=\"guide\""))
  assert_true(player.contains("FrontierLabPlayerCore"))
}
```

```mbt check
///|
test "diagnose a trace through the unified facade" {
  let expected = @frontierlab.insertion_sort_trace([3, 1, 2])
  let diagnosis = @frontierlab.diagnose_trace(
    expected,
    contract=@frontierlab.sorted_int_sequence_contract(object_id="values"),
    expected~,
  )
  assert_true(diagnosis.passed())
  assert_eq(diagnosis.focus_step, -1)
  assert_true(diagnosis.transition_diff is None)
  assert_true(diagnosis.reference_diff is None)
  assert_true(diagnosis.focused_slice is None)
}
```

```mbt check
///|
test "debug and verify an algorithm trace" {
  let trace = @frontierlab.insertion_sort_trace([3, 1, 2])
  let diff = trace.diff(from_step=0, to_step=1)
  assert_true(!diff.is_empty())
  let hits = trace.breakpoint_hits(
    @frontierlab.TraceBreakpoint::new(event_kind="swap", changed_only=true),
  )
  assert_true(!hits.is_empty())
  let report = @frontierlab.insertion_sort_int_contract(object_id="values").check(
    trace,
  )
  assert_true(report.passed)
}
```

```mbt check
///|
test "build one and two dimensional dynamic programming traces" {
  let fibonacci = @frontierlab.fibonacci_dp_trace(10)
  assert_eq(fibonacci.summary[3].value, "55")
  let coins = @frontierlab.coin_change_dp_trace([1, 3, 4], 6)
  assert_eq(coins.summary[3].value, "2")
  let knapsack = @frontierlab.zero_one_knapsack_dp_trace(
    [2, 3, 4],
    [4, 5, 6],
    5,
  )
  assert_eq(knapsack.summary[4].value, "9")
  let lcs = @frontierlab.lcs_dp_trace("ABCBDAB", "BDCABA")
  assert_eq(lcs.summary[3].value, "4")
  assert_eq(lcs.summary[4].value, "BCBA")
}
```

```mbt check
///|
test "trace red black tree balancing and lookup" {
  let trace = @frontierlab.red_black_tree_trace([
    @frontierlab.Insert(30),
    @frontierlab.Insert(10),
    @frontierlab.Insert(20),
    @frontierlab.Find(20),
    @frontierlab.Find(99),
  ])
  let stats = trace.analyze()
  assert_true(stats.event_count("rb-rotate-left") > 0)
  assert_true(stats.event_count("rb-rotate-right") > 0)
  assert_eq(stats.event_count("rb-find-hit"), 1)
  assert_eq(stats.event_count("rb-find-miss"), 1)
}
```