feat(reporting): use coveralls' new branch reporting format (#145)

* Use coveralls' new branch reporting format

* Improve comments for branch coverage and remove redundant tests

* Add --branch to coverage run in tox.ini

coveralls/reporter.py

@@ -58,12 +58,31 @@ def get_hits(self, line_num, analysis):
             return 0
         if line_num not in analysis.statements:
             return None
-        if not analysis.has_arcs():
-            return 1
-        if line_num in analysis.missing_branch_arcs():
-            return 0
         return 1
 
+    def get_arcs(self, analysis):
+        """ Hit stats for each branch.
+
+            Returns a flat list where every four values represent a branch:
+            1. line-number
+            2. block-number (not used)
+            3. branch-number
+            4. hits (we only get 1/0 from coverage.py)
+        """
+        if not analysis.has_arcs():
+            return None
+        branch_lines = analysis.branch_lines()
+        executed = analysis.arcs_executed()
+        missing = analysis.arcs_missing()
+        branches = []
+        for l1, l2 in executed:
+            if l1 in branch_lines:
+                branches.extend((l1, 0, abs(l2), 1))
+        for l1, l2 in missing:
+            if l1 in branch_lines:
+                branches.extend((l1, 0, abs(l2), 0))
+        return branches
+
     def parse_file(self, cu, analysis):
         """ Generate data for single file """
         if hasattr(analysis, 'parser'):
@@ -88,8 +107,14 @@ def parse_file(self, cu, analysis):
             source_lines = list(enumerate(analysis.file_reporter.source_token_lines()))
             source = analysis.file_reporter.source()
         coverage_lines = [self.get_hits(i, analysis) for i in range(1, len(source_lines) + 1)]
-        self.source_files.append({
+
+        results = {
             'name': filename,
             'source': source,
-            'coverage': coverage_lines
-        })
+            'coverage': coverage_lines,
+        }
+        branches = self.get_arcs(analysis)
+        if branches:
+            results['branches'] = branches
+
+        self.source_files.append(results)

tests/test_api.py

@@ -168,6 +168,7 @@ def assert_coverage(actual, expected):
     assert actual['source'].strip() == expected['source'].strip()
     assert actual['name'] == expected['name']
     assert actual['coverage'] == expected['coverage']
+    assert actual.get('branches') == expected.get('branches')
 
 
 class ReporterTest(unittest.TestCase):
@@ -194,13 +195,21 @@ def test_reporter_with_branches(self):
         sh.coverage('run', '--branch', 'runtests.py')
         results = self.cover.get_coverage()
         assert len(results) == 2
+
+        # Branches are expressed as four values each in a flat list
+        assert not len(results[0]['branches']) % 4
+        assert not len(results[1]['branches']) % 4
+
         assert_coverage({
             'source': '# coding: utf-8\n\n\ndef hello():\n    print(\'world\')\n\n\nclass Foo(object):\n    """ Bar """\n\n\ndef baz():\n    print(\'this is not tested\')\n\ndef branch(cond1, cond2):\n    if cond1:\n        print(\'condition tested both ways\')\n    if cond2:\n        print(\'condition not tested both ways\')',
             'name': 'project.py',
-            'coverage': [None, None, None, 1, 1, None, None, 1, None, None, None, 1, 0, None, 1, 1, 1, 0, 1]}, results[0])
+            'branches': [16, 0, 17, 1, 16, 0, 18, 1, 18, 0, 19, 1, 18, 0, 15, 0],
+            'coverage': [None, None, None, 1, 1, None, None, 1, None, None, None, 1, 0, None, 1, 1, 1, 1, 1]}, results[0])
         assert_coverage({
             'source': "# coding: utf-8\nfrom project import hello, branch\n\nif __name__ == '__main__':\n    hello()\n    branch(False, True)\n    branch(True, True)",
-            'name': 'runtests.py', 'coverage': [None, 1, None, 0, 1, 1, 1]}, results[1])
+            'name': 'runtests.py',
+            'branches': [4, 0, 5, 1, 4, 0, 2, 0],
+            'coverage': [None, 1, None, 1, 1, 1, 1]}, results[1])
 
     def test_missing_file(self):
         sh.echo('print("Python rocks!")', _out="extra.py")

tox.ini

@@ -14,7 +14,7 @@ deps =
     cov4: coverage>=4.0,<4.1
     cov41: coverage>=4.1
 commands =
-    coverage run --source=coveralls setup.py test
+    coverage run --branch --source=coveralls setup.py test
     coverage report -m
 
 [testenv:coveralls3]