tests: Ignore Textual snapshot mismatches on 3.7

The snapshots we've generated using current versions of Textual aren't
expected to match anymore on Python 3.7, as Textual dropped support for
Python 3.7 in the 0.44 release. However, we'd still like to run our
snapshot tests on Python 3.7, to confirm that no unexpected exceptions
occur and that the app doesn't crash. So, force `--snapshot-update` to
always be used on old versions of Python, ensuring that the tests run
but mismatching snapshots are not errors (and instead generate new
snapshot files which we'll ignore).

Signed-off-by: Matt Wozniski <mwozniski@bloomberg.net>

Author: godlygeek

tests/conftest.py

@@ -14,9 +14,13 @@ def free_port():
 
 
 def pytest_configure(config):
-    # Several of the tree reporter tests require Textual 0.48, which does not
-    # support Python 3.7, but skipping those tests causes the test suite to
-    # fail due to unused snapshots. Override the configuration for Python 3.7
-    # so that unused snapshots are a warning, not an error.
+    # The snapshots we've generated using current versions of Textual aren't
+    # expected to match anymore on Python 3.7, as Textual dropped support for
+    # Python 3.7 in the 0.44 release. However, we'd still like to run our
+    # snapshot tests on Python 3.7, to confirm that no unexpected exceptions
+    # occur and that the app doesn't crash. So, force `--snapshot-update`
+    # to always be used on old versions of Python, ensuring that the tests run
+    # but mismatching snapshots are not errors (and instead generate new
+    # snapshot files which we'll ignore).
     if sys.version_info < (3, 8):
-        config.option.warn_unused_snapshots = True
+        config.option.update_snapshots = True

tests/unit/test_tree_reporter.py

@@ -1,4 +1,3 @@
-import sys
 from dataclasses import dataclass
 from textwrap import dedent
 from typing import Any
@@ -1561,10 +1560,6 @@ def compare_impl(
 
 
 class TestTUILooks:
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_basic(self, compare):
         # GIVEN
         code = dedent(
@@ -1599,10 +1594,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.48 or higher, which doesn't support 3.7",
-    )
     def test_basic_node_selected_not_leaf(self, compare):
         # GIVEN
         code = dedent(
@@ -1637,10 +1628,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 2])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_basic_node_selected_leaf(self, compare):
         # GIVEN
         code = dedent(
@@ -1675,10 +1662,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 3])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_two_chains(self, compare):
         # GIVEN
         code = dedent(
@@ -1726,10 +1709,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.48 or higher, which doesn't support 3.7",
-    )
     def test_two_chains_after_expanding_second(self, compare):
         # GIVEN
         code = dedent(
@@ -1779,10 +1758,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 4, "e"])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_hide_import_system(self, compare):
         # GIVEN
         code = dedent(
@@ -1833,10 +1808,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=["i"])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_show_uninteresting(self, compare):
         # GIVEN
         code = dedent(
@@ -1887,10 +1858,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=["u"])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_show_uninteresting_and_hide_import_system(self, compare):
         # GIVEN
         code = dedent(
@@ -1942,10 +1909,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=["u", "i"])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.48 or higher, which doesn't support 3.7",
-    )
     def test_select_screen(self, tmp_path, compare):
         # GIVEN
         code = dedent(
@@ -1979,10 +1942,6 @@ def generate_primes():
             getlines.return_value = code.splitlines()
             assert compare(peak_allocations, press=[*["down"] * 3])
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_allocations_of_different_sizes(self, compare):
         # GIVEN
         peak_allocations = [
@@ -2003,10 +1962,6 @@ def test_allocations_of_different_sizes(self, compare):
             getlines.return_value = []
             assert compare(peak_allocations, press=[], terminal_size=(350, 100))
 
-    @pytest.mark.skipif(
-        sys.version_info < (3, 8),
-        reason="This test requires Textual 0.49 or higher, which doesn't support 3.7",
-    )
     def test_biggest_allocations(self, compare):
         # GIVEN
         peak_allocations = [