fix(typing): Resolve test_magics

- Uses standardised import checking/skipping
- Imports `InteractiveShell` from the module
- Replaces global scope with fixtures

pyproject.toml

@@ -468,6 +468,5 @@ ignore=[
     "./sphinxext/",
     "./tests/test_jupyter_chart.py",
     "./tests/utils/",
-    "./tests/test_magics.py",
     "../../../**/Lib", # stdlib
 ]

tests/__init__.py

@@ -59,6 +59,17 @@ def windows_has_tzdata() -> bool:
     >>> hatch run test-slow --durations=25  # doctest: +SKIP
 """
 
+skip_requires_ipython: pytest.MarkDecorator = pytest.mark.skipif(
+    find_spec("IPython") is None, reason="`IPython` not installed."
+)
+"""
+``pytest.mark.skipif`` decorator.
+
+Applies when `IPython`_ import would fail.
+
+.. _IPython:
+   /~https://github.com/ipython/ipython
+"""
 
 skip_requires_vl_convert: pytest.MarkDecorator = pytest.mark.skipif(
     find_spec("vl_convert") is None, reason="`vl_convert` not installed."

tests/test_magics.py

@@ -1,68 +1,76 @@
+from __future__ import annotations
+
 import json
+from typing import TYPE_CHECKING, Any
 
 import pytest
 
-try:
-    from IPython import InteractiveShell
-
-    IPYTHON_AVAILABLE = True
-except ImportError:
-    IPYTHON_AVAILABLE = False
-
-from altair.vegalite.v5 import VegaLite
-
-DATA_RECORDS = [
-    {"amount": 28, "category": "A"},
-    {"amount": 55, "category": "B"},
-    {"amount": 43, "category": "C"},
-    {"amount": 91, "category": "D"},
-    {"amount": 81, "category": "E"},
-    {"amount": 53, "category": "F"},
-    {"amount": 19, "category": "G"},
-    {"amount": 87, "category": "H"},
-]
-
-if IPYTHON_AVAILABLE:
-    _ipshell = InteractiveShell.instance()
-    _ipshell.run_cell("%load_ext altair")
-    _ipshell.run_cell(
-        f"""
-import pandas as pd
-table = pd.DataFrame.from_records({DATA_RECORDS})
-the_data = table
-"""
-    )
+from altair.vegalite.v5.display import VegaLite
+from tests import skip_requires_ipython
+
+if TYPE_CHECKING:
+    from IPython.core.interactiveshell import InteractiveShell
+
+
+@pytest.fixture
+def records() -> list[dict[str, Any]]:
+    return [
+        {"amount": 28, "category": "A"},
+        {"amount": 55, "category": "B"},
+        {"amount": 43, "category": "C"},
+        {"amount": 91, "category": "D"},
+        {"amount": 81, "category": "E"},
+        {"amount": 53, "category": "F"},
+        {"amount": 19, "category": "G"},
+        {"amount": 87, "category": "H"},
+    ]
 
 
-VEGALITE_SPEC = {
-    "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
-    "data": {"values": DATA_RECORDS},
-    "description": "A simple bar chart with embedded data.",
-    "encoding": {
-        "x": {"field": "category", "type": "ordinal"},
-        "y": {"field": "amount", "type": "quantitative"},
-    },
-    "mark": {"type": "bar"},
-}
+@pytest.fixture
+def vl_spec(records) -> dict[str, Any]:
+    return {
+        "$schema": "https://vega.github.io/schema/vega-lite/v5.json",
+        "data": {"values": records},
+        "description": "A simple bar chart with embedded data.",
+        "encoding": {
+            "x": {"field": "category", "type": "ordinal"},
+            "y": {"field": "amount", "type": "quantitative"},
+        },
+        "mark": {"type": "bar"},
+    }
+
+
+@pytest.fixture
+def ipshell(records) -> InteractiveShell:
+    from IPython.core.interactiveshell import InteractiveShell
+
+    shell = InteractiveShell.instance()
+    shell.run_cell("%load_ext altair")
+    shell.run_cell(
+        f"import pandas as pd\n"
+        f"table = pd.DataFrame.from_records({records})\n"
+        f"the_data = table"
+    )
+    return shell
 
 
-@pytest.mark.skipif(not IPYTHON_AVAILABLE, reason="requires ipython")
-def test_vegalite_magic_data_included():
-    result = _ipshell.run_cell("%%vegalite\n" + json.dumps(VEGALITE_SPEC))
+@skip_requires_ipython
+def test_vegalite_magic_data_included(ipshell, vl_spec) -> None:
+    result = ipshell.run_cell("%%vegalite\n" + json.dumps(vl_spec))
     assert isinstance(result.result, VegaLite)
-    assert result.result.spec == VEGALITE_SPEC
+    assert result.result.spec == vl_spec
 
 
-@pytest.mark.skipif(not IPYTHON_AVAILABLE, reason="requires ipython")
-def test_vegalite_magic_json_flag():
-    result = _ipshell.run_cell("%%vegalite --json\n" + json.dumps(VEGALITE_SPEC))
+@skip_requires_ipython
+def test_vegalite_magic_json_flag(ipshell, vl_spec) -> None:
+    result = ipshell.run_cell("%%vegalite --json\n" + json.dumps(vl_spec))
     assert isinstance(result.result, VegaLite)
-    assert result.result.spec == VEGALITE_SPEC
+    assert result.result.spec == vl_spec
 
 
-@pytest.mark.skipif(not IPYTHON_AVAILABLE, reason="requires ipython")
-def test_vegalite_magic_pandas_data():
-    spec = {key: val for key, val in VEGALITE_SPEC.items() if key != "data"}
-    result = _ipshell.run_cell("%%vegalite table\n" + json.dumps(spec))
+@skip_requires_ipython
+def test_vegalite_magic_pandas_data(ipshell, vl_spec) -> None:
+    spec = {key: val for key, val in vl_spec.items() if key != "data"}
+    result = ipshell.run_cell("%%vegalite table\n" + json.dumps(spec))
     assert isinstance(result.result, VegaLite)
-    assert result.result.spec == VEGALITE_SPEC
+    assert result.result.spec == vl_spec