feat(graph): add graph tab for whole-run data

Provides a static line chart plotting multi-sensor temperature values
over time when a session file is loaded.

tests/test_frame_player.py

@@ -1,5 +1,5 @@
 from pygui.backend.models.frame import Frame
-from pygui.backend.models.frame_player import FramePlayer
+from pygui.backend.models.frame_player import FramePlayer, all_sensor_series
 
 
 def frames(n):
@@ -29,3 +29,24 @@ def test_at_end():
     assert not p.at_end
     p.seek(1)
     assert p.at_end
+
+def test_frames_property_exposes_loaded_frames():
+    p = FramePlayer(); p.load(frames(3))
+    assert p.frames == tuple(frames(3))
+
+
+# ---- all_sensor_series (Graph tab whole-run assembly) ----
+
+def test_all_sensor_series_empty_frames():
+    assert all_sensor_series([]) == ([], [])
+
+
+def test_all_sensor_series_names_and_columns():
+    fs = [
+        Frame(seq=0, time=0.0, values=[150.0, 148.0]),
+        Frame(seq=1, time=1.0, values=[151.0, 147.5]),
+        Frame(seq=2, time=2.0, values=[152.0, 147.0]),
+    ]
+    names, series = all_sensor_series(fs)
+    assert names == ["Sensor 1", "Sensor 2"]
+    assert series == [[150.0, 151.0, 152.0], [148.0, 147.5, 147.0]]

tests/test_graph_quick_item.py

@@ -0,0 +1,61 @@
+"""Tests for src/pygui/backend/visualization/graph_quick_item.py."""
+import pytest
+
+pytestmark = pytest.mark.usefixtures("qapp")
+
+
+def test_no_data_initially():
+    from pygui.backend.visualization.graph_quick_item import GraphQuickItem
+
+    item = GraphQuickItem()
+    assert item.seriesData == []
+    assert item.sensorNames == []
+
+
+def test_series_data_setter_stores_series():
+    from pygui.backend.visualization.graph_quick_item import GraphQuickItem
+
+    item = GraphQuickItem()
+    item.seriesData = [[150.0, 151.0], [148.0, 147.5]]
+
+    assert item.seriesData == [[150.0, 151.0], [148.0, 147.5]]
+
+
+def test_series_data_auto_ranges_y_with_padding():
+    from pygui.backend.visualization.graph_quick_item import GraphQuickItem
+
+    item = GraphQuickItem()
+    item.seriesData = [[150.0, 100.0], [200.0, 120.0]]
+
+    # min=100, max=200, range=100, 10% pad => [90, 210]
+    assert item._min_y == pytest.approx(90.0)
+    assert item._max_y == pytest.approx(210.0)
+
+
+def test_series_data_empty_keeps_default_range():
+    from pygui.backend.visualization.graph_quick_item import GraphQuickItem
+
+    item = GraphQuickItem()
+    item.seriesData = []
+
+    assert item._min_y == 0.0
+    assert item._max_y == 150.0
+
+
+def test_sensor_names_setter_stores_names():
+    from pygui.backend.visualization.graph_quick_item import GraphQuickItem
+
+    item = GraphQuickItem()
+    item.sensorNames = ["Sensor 1", "Sensor 2"]
+
+    assert item.sensorNames == ["Sensor 1", "Sensor 2"]
+
+
+def test_non_numeric_values_are_skipped_not_crashing():
+    from pygui.backend.visualization.graph_quick_item import GraphQuickItem
+
+    item = GraphQuickItem()
+    item.seriesData = [[150.0, "bad", 151.0]]
+
+    assert item._min_y == pytest.approx(149.9)
+    assert item._max_y == pytest.approx(151.1)

tests/test_graph_view.py

@@ -66,6 +66,51 @@ class TestUpdateTrend:
         gv.updateTrend("[1, 2, 3]")
 
 
+class TestUpdateChart:
+    def test_plots_one_series_per_sensor(self):
+        from pygui.backend.visualization.graph_view import GraphView
+
+        gv = GraphView()
+        gv._plot_widget = _make_plot_widget()
+
+        series = [[150.0, 151.0, 152.0], [148.5, 148.4, 148.6]]
+        gv.updateChart("Sensor 1,Sensor 2", json.dumps(series))
+
+        assert gv._plot_widget.clear.called
+        assert gv._plot_widget.plot.call_count == 2
+        assert gv._sensor_names == ["Sensor 1", "Sensor 2"]
+
+    def test_rejects_invalid_json(self):
+        from pygui.backend.visualization.graph_view import GraphView
+
+        gv = GraphView()
+        gv._plot_widget = _make_plot_widget()
+
+        gv.updateChart("Sensor 1", "not json")
+
+        assert not gv._plot_widget.plot.called
+
+    def test_empty_series_clears_without_plotting(self):
+        from pygui.backend.visualization.graph_view import GraphView
+
+        gv = GraphView()
+        gv._plot_widget = _make_plot_widget()
+
+        gv.updateChart("", "[]")
+
+        assert gv._plot_widget.clear.called
+        assert not gv._plot_widget.plot.called
+
+    def test_no_plot_widget(self):
+        from pygui.backend.visualization.graph_view import GraphView
+
+        gv = GraphView()
+        assert gv._plot_widget is None
+
+        # Should not crash
+        gv.updateChart("Sensor 1", json.dumps([[1.0, 2.0]]))
+
+
 class TestUpdateComparison:
     def test_parses_valid_json(self):
         from pygui.backend.visualization.graph_view import GraphView

tests/test_session_controller.py

@@ -53,6 +53,26 @@ def test_pause_stop_timer(controller):
     controller.stop()
     assert controller.frameIndex == 0
 
+def test_graph_data_empty_before_load(controller):
+    assert controller.graphSensorNames == ""
+    assert controller.graphSeriesJson == "[]"
+
+def test_graph_data_after_load(controller):
+    controller.loadFile("tests/fixtures/sample_stream.csv")
+    assert controller.graphSensorNames == "Sensor 1,Sensor 2,Sensor 3"
+    series = json.loads(controller.graphSeriesJson)
+    assert series == [
+        [149.0, 149.2, 149.1],
+        [148.5, 148.4, 148.6],
+        [150.6, 150.7, 150.5],
+    ]
+
+def test_graph_data_cleared_after_unload(controller):
+    controller.loadFile("tests/fixtures/sample_stream.csv")
+    controller.unloadFile()
+    assert controller.graphSensorNames == ""
+    assert controller.graphSeriesJson == "[]"
+
 def test_leaving_live_mode_blanks_wafer_map(controller):
     """Stopping a live session (tab switch → setMode) must not leave stale
     sensor values on the wafer map — it should read as blank."""