Add repr of ScanSpec to Scan Plan metadata and add tests to prove #50 …

…is resolved

Resolves #50

src/blueapi/plans/plans.py

@@ -38,7 +38,7 @@ def scan(
 
     metadata = {
         "detectors": [detector.name for detector in detectors],
-        # "scanspec": serialize(spec, default_conversion=_convert_devices),
+        "scanspec": repr(spec),
         "shape": spec.shape(),
         **(metadata or {}),
     }

tests/plans/test_scanspec_metadata.py

@@ -0,0 +1,91 @@
+from asyncio import Future
+
+import pytest
+from bluesky import RunEngine
+from ophyd.sim import Syn2DGauss, SynAxis, SynGauss
+from scanspec.specs import Line, Spiral
+
+from blueapi.plans import scan
+
+
+@pytest.fixture
+def run_engine() -> RunEngine:
+    return RunEngine({})
+
+
+@pytest.fixture
+def x() -> SynAxis:
+    return SynAxis(name="x")
+
+
+@pytest.fixture
+def y() -> SynAxis:
+    return SynAxis(name="y")
+
+
+def capture_document_return_token(future: Future, run_engine: RunEngine, name) -> int:
+    def set_result(_, doc):
+        future.set_result(doc)
+
+    return run_engine.subscribe(name=name, func=set_result)
+
+
+def test_metadata_of_simple_spec(run_engine, x):
+    det = SynGauss(
+        name="det",
+        motor=x,
+        motor_field=x.name,
+        center=0.0,
+        Imax=1,
+        labels={"detectors"},
+    )
+    spec = Line(axis=x.name, start=1, stop=2, num=3)
+    x_points = [1.0, 1.5, 2.0]
+    spec_repr = "Line(axis='x', start=1.0, stop=2.0, num=3)"
+
+    start_future = Future()
+    tok = capture_document_return_token(start_future, run_engine, "start")
+    run_engine(scan([det], {x.name: x}, spec))
+    run_engine.unsubscribe(tok)
+
+    start_document = start_future.result()
+    plan_args = start_document["plan_args"]
+    assert plan_args["detectors"] == [repr(det)]
+    assert plan_args["cycler"] == f"cycler({repr(x)}, {x_points})"
+    assert start_document["motors"] == [x.name]
+    assert start_document["detectors"] == [det.name]
+    assert start_document["scanspec"] == spec_repr
+
+
+def test_metadata_of_spiral_spec(run_engine, x, y):
+    det = Syn2DGauss(
+        name="det",
+        motor0=x,
+        motor_field0=x.name,
+        motor1=y,
+        motor_field1=y.name,
+        center=(0.0, 0.0),
+        Imax=1,
+        labels={"detectors"},
+    )
+    spec = Spiral.spaced(x.name, y.name, 0, 0, 5, 1)
+
+    start_future = Future()
+    tok = capture_document_return_token(start_future, run_engine, "start")
+    run_engine(scan([det], {x.name: x, y.name: y}, spec))
+    run_engine.unsubscribe(tok)
+
+    start_document = start_future.result()
+    plan_args = start_document["plan_args"]
+
+    assert plan_args["detectors"] == [repr(det)]
+    midpoints = spec.midpoints()
+    x_cycler = f"cycler({repr(x)}, {[a[x.name] for a in midpoints]})"
+    y_cycler = f"cycler({repr(y)}, {[a[y.name] for a in midpoints]})"
+    assert plan_args["cycler"] == f"({y_cycler} + {x_cycler})"
+    assert set(start_document["motors"]) == {
+        x.name,
+        y.name,
+    }  # Order of motors in scan_nd not guaranteed
+    assert start_document["detectors"] == [det.name]
+    assert start_document["scanspec"] == repr(spec)