Fix branch coverage rate comparison when used with --branch without actual branches

src/genbadge/utils_coverage.py

@@ -24,13 +24,14 @@ class CoverageStats(object):
     Contains the results from parsing the coverage.xml.
     """
     def __init__(self,
-                 branches_covered=None, branches_valid=None,
-                 complexity=None, lines_covered=None, lines_valid=None
+                 branches_covered=None, branches_valid=None, branch_option=None,
+                 complexity=None, lines_covered=None, lines_valid=None,
                  ):
         self.complexity = complexity
 
         self.branches_covered = branches_covered
         self.branches_valid = branches_valid
+        self.branch_option = branch_option
 
         self.lines_covered = lines_covered
         self.lines_valid = lines_valid
@@ -40,10 +41,14 @@ def branch_rate(self):
         """
         Note: in --no-branch situations, the number of branches is 0.
         In that case, the branch rate is 0 in the coverage.xml.
-        We mimic the behaviour in this field to be consistent.
+        But in --branch situations without actual branches,
+        the number of branches is also 0 but the branch rate is 1.
+        We mimic both behaviours in this field to be consistent.
         """
         if self.branches_valid > 0:
             return self.branches_covered / self.branches_valid
+        elif self.branch_option:
+            return 1
         else:
             return 0
 
@@ -162,12 +167,13 @@ def parse_root(self, root):
         branch_rate = float(root.attrib.get('branch-rate'))
         line_rate = float(root.attrib.get('line-rate'))
 
+        # detect whether the --branch option were set or not
+        # so CoverageStats knows how to distinguish between them
+        cov.branch_option = cov.branches_valid > 0 or branch_rate == 1.0
+
         if not is_close(cov.branch_rate, branch_rate):
-            # if branch=true but there are no actual branches coverage will report
-            # branches-valid="0" and branch-rate="1"
-            if cov.branches_valid != 0 or branch_rate != 1.0:
-                raise ValueError("Computed branch rate (%s) is different from the one in the file (%s)"
-                                 % (cov.branch_rate, branch_rate))
+            raise ValueError("Computed branch rate (%s) is different from the one in the file (%s)"
+                             % (cov.branch_rate, branch_rate))
         if not is_close(cov.line_rate, line_rate):
             raise ValueError("Computed line rate (%s) is different from the one in the file (%s)"
                              % (cov.line_rate, line_rate))

tests/reports/coverage/coverage_branch_without_branches.xml

@@ -0,0 +1,23 @@
+<?xml version="1.0" ?>
+<coverage version="7.6.1" timestamp="1725577267091" lines-valid="4" lines-covered="3" line-rate="0.75" branches-valid="0" branches-covered="0" branch-rate="1" complexity="0">
+	<!-- Generated by coverage.py: https://coverage.readthedocs.io/en/7.6.1 -->
+	<!-- Based on https://raw.githubusercontent.com/cobertura/web/master/htdocs/xml/coverage-04.dtd -->
+	<sources>
+		<source>/home/marce_geek/UTN/4/Agiles/python-actions-test</source>
+	</sources>
+	<packages>
+		<package name="." line-rate="0.75" branch-rate="1" complexity="0">
+			<classes>
+				<class name="mymodule.py" filename="mymodule.py" complexity="0" line-rate="0.75" branch-rate="1">
+					<methods/>
+					<lines>
+						<line number="1" hits="1"/>
+						<line number="2" hits="1"/>
+						<line number="5" hits="1"/>
+						<line number="6" hits="0"/>
+					</lines>
+				</class>
+			</classes>
+		</package>
+	</packages>
+</coverage>

tests/test_core.py

@@ -182,6 +182,25 @@ def test_parse_cov_nobranch_issue_15():
     assert res.total_coverage == 100 * res.total_rate
 
 
+def test_parse_cov_branch_without_branches():
+    """Check that we can parse a coverage.xml file successfully with the branch option without actual branches"""
+    res = parse_cov(str(TESTS_FOLDER / "reports/coverage/coverage_branch_without_branches.xml"))
+
+    assert res.branches_valid == 0
+    assert res.branches_covered == 0
+    assert res.branch_rate == 1
+
+    assert res.lines_valid == 4
+    assert res.lines_covered == 3
+    assert res.line_rate == res.lines_covered / res.lines_valid
+
+    assert res.branch_coverage == res.branch_rate * 100
+    assert res.line_coverage == res.line_rate * 100
+
+    assert res.total_rate == ((res.lines_covered + res.branches_covered) / (res.branches_valid + res.lines_valid))
+    assert res.total_coverage == 100 * res.total_rate
+
+
 def test_parse_flake8():
     """Check that we can parse a coverage.xml file successfully"""
     res = get_flake8_stats(str(TESTS_FOLDER / "reports/flake8/flake8stats.txt"))