Preserve supplied XML attributes during lazy statistics reads

src/junitparser/junitparser.py

@@ -11,7 +11,7 @@
 
 import io
 import itertools
-from copy import deepcopy
+from copy import copy, deepcopy
 from pathlib import Path
 from typing import List, Iterator, IO
 
@@ -97,6 +97,16 @@ def __set__(self, instance, value: str):
             instance._elem.attrib[self.name] = str(value)
 
 
+def _update_missing_statistics(instance):
+    """Fill absent summary attributes without rewriting supplied XML values."""
+    calculated = copy(instance)
+    calculated._elem = deepcopy(instance._elem)
+    calculated.update_statistics()
+    for name, value in calculated._elem.attrib.items():
+        if name not in instance._elem.attrib:
+            instance._elem.attrib[name] = value
+
+
 class IntAttr(Attr):
     """An integer attribute for an XML element.
 
@@ -107,7 +117,7 @@ class IntAttr(Attr):
     def __get__(self, instance, cls):
         result = super().__get__(instance, cls)
         if result is None and isinstance(instance, (JUnitXml, TestSuite)):
-            instance.update_statistics()
+            _update_missing_statistics(instance)
             result = super().__get__(instance, cls)
         return int(result) if result else None
 
@@ -127,7 +137,7 @@ class FloatAttr(Attr):
     def __get__(self, instance, cls):
         result = super().__get__(instance, cls)
         if result is None and isinstance(instance, (JUnitXml, TestSuite)):
-            instance.update_statistics()
+            _update_missing_statistics(instance)
             result = super().__get__(instance, cls)
         return float(result.replace(",", "")) if result else None
 

tests/test_lazy_statistics.py

@@ -0,0 +1,153 @@
+import io
+import threading
+
+import pytest
+
+from src.junitparser import JUnitXml, TestCase, TestSuite
+from src.junitparser import xunit2
+
+
+PARALLEL = (
+    '<testsuites><testsuite name="parallel" time="10">'
+    '<testcase name="a" time="8"/><testcase name="b" time="9"/>'
+    "</testsuite></testsuites>"
+)
+
+
+@pytest.mark.parametrize(
+    "attribute,value",
+    [("tests", 2), ("errors", 0), ("failures", 0), ("skipped", 0), ("time", 17)],
+)
+def test_missing_root_statistics_preserve_reported_time(attribute, value):
+    report = JUnitXml.fromstring(PARALLEL)
+    suite = next(iter(report))
+    assert getattr(report, attribute) == value
+    assert suite.time == 10
+    output = io.BytesIO()
+    report.write(output)
+    assert next(iter(JUnitXml.fromfile(io.BytesIO(output.getvalue())))).time == 10
+    report.update_statistics()
+    assert suite.time == 17
+
+
+@pytest.mark.parametrize(
+    "attribute,value", [("tests", 2), ("errors", 0), ("failures", 0), ("skipped", 0)]
+)
+def test_missing_suite_statistics_preserve_reported_time(attribute, value):
+    suite = next(iter(JUnitXml.fromstring(PARALLEL)))
+    assert getattr(suite, attribute) == value
+    assert suite.time == 10
+
+
+def test_missing_time_preserves_explicit_counts():
+    suite = TestSuite.fromstring(
+        '<testsuite tests="42"><testcase time="8"/></testsuite>'
+    )
+    assert suite.time == 8
+    assert suite.tests == 42
+    suite.update_statistics()
+    assert suite.tests == 1
+
+
+def test_zero_is_not_missing_and_mutations_still_recompute():
+    suite = TestSuite.fromstring(
+        '<testsuite tests="0" time="0"><testcase time="8"/></testsuite>'
+    )
+    assert suite.failures == 0
+    assert suite.tests == 0
+    assert suite.time == 0
+    suite.add_testcase(TestCase("extra", time=3))
+    assert suite.time == 11
+    assert suite.tests == 2
+
+
+def test_lazy_statistics_do_not_copy_non_xml_subclass_state():
+    class LockedSuite(TestSuite):
+        def __init__(self):
+            super().__init__()
+            self.lock = threading.Lock()
+
+    suite = LockedSuite.fromstring(
+        '<testsuite time="10"><testcase time="8"/></testsuite>'
+    )
+    assert suite.tests == 1
+    assert suite.time == 10
+
+
+def test_missing_standard_statistics_are_cached_together():
+    class CountingSuite(TestSuite):
+        calls = 0
+
+        def update_statistics(self):
+            type(self).calls += 1
+            super().update_statistics()
+
+    suite = CountingSuite.fromstring(
+        '<testsuite time="10"><testcase time="8"/></testsuite>'
+    )
+    assert (suite.tests, suite.errors, suite.failures, suite.skipped) == (1, 0, 0, 0)
+    assert CountingSuite.calls == 1
+    assert suite.time == 10
+
+
+def test_nested_xunit2_preserves_annotations():
+    report = xunit2.JUnitXml.fromstring(
+        '<testsuites><testsuite time="10"><testsuite time="6"><testcase time="8"/><testcase time="9"/></testsuite></testsuite></testsuites>'
+    )
+    outer = next(iter(report))
+    inner = next(outer.testsuites())
+    assert report.tests == 2
+    assert report.time == 17
+    assert report.skipped is None
+    assert "skipped" not in report._elem.attrib
+    assert outer.time == 10
+    assert inner.time == 6
+
+
+@pytest.mark.parametrize("descriptor,value", [("IntAttr", 7), ("FloatAttr", 7.5)])
+def test_custom_computed_numeric_attribute(descriptor, value):
+    from src.junitparser import FloatAttr, IntAttr
+
+    descriptor_type = {"IntAttr": IntAttr, "FloatAttr": FloatAttr}[descriptor]
+
+    class CustomSuite(TestSuite):
+        custom = descriptor_type()
+        absent = descriptor_type()
+
+        def update_statistics(self):
+            super().update_statistics()
+            self.custom = value
+
+    suite = CustomSuite.fromstring(
+        '<testsuite time="10"><testcase time="8"/></testsuite>'
+    )
+    assert suite.custom == value
+    assert suite.absent is None
+    assert suite.time == 10
+
+
+def test_computed_custom_metadata_is_cached_with_statistics():
+    from src.junitparser import Attr
+
+    class CustomSuite(TestSuite):
+        label = Attr()
+        calls = 0
+
+        def update_statistics(self):
+            type(self).calls += 1
+            super().update_statistics()
+            self.label = "calculated"
+
+    suite = CustomSuite.fromstring(
+        '<testsuite time="10"><testcase time="8"/></testsuite>'
+    )
+    assert suite.tests == 1
+    assert suite.label == "calculated"
+    assert suite.errors == 0
+    assert CustomSuite.calls == 1
+    assert suite.time == 10
+    explicit = CustomSuite.fromstring(
+        '<testsuite label="supplied" time="10"><testcase time="8"/></testsuite>'
+    )
+    assert explicit.tests == 1
+    assert explicit.label == "supplied"