Be a little clearer about when we expect one thing, and when we expect a list

4 files changed, 74 insertions, 46 deletions

diff --git a/coverage/codeunit.py b/coverage/codeunit.py
index 8265a786..dc9a7ee6 100644
--- a/coverage/codeunit.py
+++ b/coverage/codeunit.py
@@ -10,10 +10,10 @@ from coverage.parser import PythonParser
 from coverage.phystokens import source_token_lines, source_encoding
 
 
-def code_unit_factory(morfs, file_locator, get_plugin=None):
-    """Construct a list of CodeUnits from polymorphic inputs.
+def code_units_factory(morfs, file_locator, get_plugin=None):
+    """Construct a list of CodeUnits from modules or filenames.
 
-    `morfs` is a module or a filename, or a list of same.
+    `morfs` is a module or filename, or a list of the same.
 
     `file_locator` is a FileLocator that can help resolve filenames.
 
@@ -30,24 +30,45 @@ def code_unit_factory(morfs, file_locator, get_plugin=None):
 
     code_units = []
     for morf in morfs:
-        plugin = None
-        if isinstance(morf, string_class) and get_plugin:
-            plugin = get_plugin(morf)
-        if plugin:
-            file_reporter = plugin.file_reporter(morf)
-            if file_reporter is None:
-                raise CoverageException(
-                    "Plugin %r did not provide a file reporter for %r." % (
-                        plugin.plugin_name, morf
-                    )
-                )
-        else:
-            file_reporter = PythonCodeUnit(morf, file_locator)
+        file_reporter = code_unit_factory(morf, file_locator, get_plugin)
         code_units.append(file_reporter)
 
     return code_units
 
 
+def code_unit_factory(morf, file_locator, get_plugin=None):
+    """Construct a CodeUnit from a module or filename.
+
+    `morfs` is a module or a filename.
+
+    `file_locator` is a FileLocator that can help resolve filenames.
+
+    `get_plugin` is a function taking a filename, and returning a plugin
+    responsible for the file.  It can also return None if there is no plugin
+    claiming the file.
+
+    Returns a CodeUnit object.
+
+    """
+    plugin = None
+
+    if isinstance(morf, string_class) and get_plugin:
+        plugin = get_plugin(morf)
+
+    if plugin:
+        file_reporter = plugin.file_reporter(morf)
+        if file_reporter is None:
+            raise CoverageException(
+                "Plugin %r did not provide a file reporter for %r." % (
+                    plugin.plugin_name, morf
+                )
+            )
+    else:
+        file_reporter = PythonCodeUnit(morf, file_locator)
+
+    return file_reporter
+
+
 class CodeUnit(object):
     """Code unit: a filename or module.
 
@@ -96,14 +117,19 @@ class CodeUnit(object):
 
     def __lt__(self, other):
         return self.name < other.name
+
     def __le__(self, other):
         return self.name <= other.name
+
     def __eq__(self, other):
         return self.name == other.name
+
     def __ne__(self, other):
         return self.name != other.name
+
     def __gt__(self, other):
         return self.name > other.name
+
     def __ge__(self, other):
         return self.name >= other.name
 
@@ -157,7 +183,7 @@ class PythonCodeUnit(CodeUnit):
         # .pyc files should always refer to a .py instead.
         if fname.endswith(('.pyc', '.pyo')):
             fname = fname[:-1]
-        elif fname.endswith('$py.class'): # Jython
+        elif fname.endswith('$py.class'):   # Jython
             fname = fname[:-9] + ".py"
         return fname
 
diff --git a/coverage/control.py b/coverage/control.py
index ef430150..95592508 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -760,7 +760,7 @@ class Coverage(object):
 
         self._harvest_data()
         if not isinstance(it, CodeUnit):
-            it = code_unit_factory(it, self.file_locator, get_plugin)[0]
+            it = code_unit_factory(it, self.file_locator, get_plugin)
 
         return Analysis(self, it)
 
diff --git a/coverage/report.py b/coverage/report.py
index b93749c8..85d552e1 100644
--- a/coverage/report.py
+++ b/coverage/report.py
@@ -1,10 +1,12 @@
 """Reporter foundation for Coverage."""
 
 import os
-from coverage.codeunit import code_unit_factory
+
+from coverage.codeunit import code_units_factory
 from coverage.files import prep_patterns, FnmatchMatcher
 from coverage.misc import CoverageException, NoSource, NotPython
 
+
 class Reporter(object):
     """A base class for all reporters."""
 
@@ -34,7 +36,7 @@ class Reporter(object):
         morfs = morfs or self.coverage.data.measured_files()
         file_locator = self.coverage.file_locator
         get_plugin = self.coverage.data.plugin_data().get
-        self.code_units = code_unit_factory(morfs, file_locator, get_plugin)
+        self.code_units = code_units_factory(morfs, file_locator, get_plugin)
 
         if self.config.include:
             patterns = prep_patterns(self.config.include)
diff --git a/tests/test_codeunit.py b/tests/test_codeunit.py
index b90ac2e8..b3b188b4 100644
--- a/tests/test_codeunit.py
+++ b/tests/test_codeunit.py
@@ -3,7 +3,7 @@
 import os
 import sys
 
-from coverage.codeunit import code_unit_factory
+from coverage.codeunit import code_unit_factory, code_units_factory
 from coverage.files import FileLocator
 
 from tests.coveragetest import CoverageTest
@@ -27,36 +27,36 @@ class CodeUnitTest(CoverageTest):
         acu = code_unit_factory("aa/afile.py", FileLocator())
         bcu = code_unit_factory("aa/bb/bfile.py", FileLocator())
         ccu = code_unit_factory("aa/bb/cc/cfile.py", FileLocator())
-        self.assertEqual(acu[0].name, "aa/afile")
-        self.assertEqual(bcu[0].name, "aa/bb/bfile")
-        self.assertEqual(ccu[0].name, "aa/bb/cc/cfile")
-        self.assertEqual(acu[0].flat_rootname(), "aa_afile")
-        self.assertEqual(bcu[0].flat_rootname(), "aa_bb_bfile")
-        self.assertEqual(ccu[0].flat_rootname(), "aa_bb_cc_cfile")
-        self.assertEqual(acu[0].source(), "# afile.py\n")
-        self.assertEqual(bcu[0].source(), "# bfile.py\n")
-        self.assertEqual(ccu[0].source(), "# cfile.py\n")
+        self.assertEqual(acu.name, "aa/afile")
+        self.assertEqual(bcu.name, "aa/bb/bfile")
+        self.assertEqual(ccu.name, "aa/bb/cc/cfile")
+        self.assertEqual(acu.flat_rootname(), "aa_afile")
+        self.assertEqual(bcu.flat_rootname(), "aa_bb_bfile")
+        self.assertEqual(ccu.flat_rootname(), "aa_bb_cc_cfile")
+        self.assertEqual(acu.source(), "# afile.py\n")
+        self.assertEqual(bcu.source(), "# bfile.py\n")
+        self.assertEqual(ccu.source(), "# cfile.py\n")
 
     def test_odd_filenames(self):
         acu = code_unit_factory("aa/afile.odd.py", FileLocator())
         bcu = code_unit_factory("aa/bb/bfile.odd.py", FileLocator())
         b2cu = code_unit_factory("aa/bb.odd/bfile.py", FileLocator())
-        self.assertEqual(acu[0].name, "aa/afile.odd")
-        self.assertEqual(bcu[0].name, "aa/bb/bfile.odd")
-        self.assertEqual(b2cu[0].name, "aa/bb.odd/bfile")
-        self.assertEqual(acu[0].flat_rootname(), "aa_afile_odd")
-        self.assertEqual(bcu[0].flat_rootname(), "aa_bb_bfile_odd")
-        self.assertEqual(b2cu[0].flat_rootname(), "aa_bb_odd_bfile")
-        self.assertEqual(acu[0].source(), "# afile.odd.py\n")
-        self.assertEqual(bcu[0].source(), "# bfile.odd.py\n")
-        self.assertEqual(b2cu[0].source(), "# bfile.py\n")
+        self.assertEqual(acu.name, "aa/afile.odd")
+        self.assertEqual(bcu.name, "aa/bb/bfile.odd")
+        self.assertEqual(b2cu.name, "aa/bb.odd/bfile")
+        self.assertEqual(acu.flat_rootname(), "aa_afile_odd")
+        self.assertEqual(bcu.flat_rootname(), "aa_bb_bfile_odd")
+        self.assertEqual(b2cu.flat_rootname(), "aa_bb_odd_bfile")
+        self.assertEqual(acu.source(), "# afile.odd.py\n")
+        self.assertEqual(bcu.source(), "# bfile.odd.py\n")
+        self.assertEqual(b2cu.source(), "# bfile.py\n")
 
     def test_modules(self):
         import aa
         import aa.bb
         import aa.bb.cc
 
-        cu = code_unit_factory([aa, aa.bb, aa.bb.cc], FileLocator())
+        cu = code_units_factory([aa, aa.bb, aa.bb.cc], FileLocator())
         self.assertEqual(cu[0].name, "aa")
         self.assertEqual(cu[1].name, "aa.bb")
         self.assertEqual(cu[2].name, "aa.bb.cc")
@@ -72,7 +72,7 @@ class CodeUnitTest(CoverageTest):
         import aa.bb.bfile
         import aa.bb.cc.cfile
 
-        cu = code_unit_factory(
+        cu = code_units_factory(
             [aa.afile, aa.bb.bfile, aa.bb.cc.cfile],
             FileLocator()
         )
@@ -87,10 +87,10 @@ class CodeUnitTest(CoverageTest):
         self.assertEqual(cu[2].source(), "# cfile.py\n")
 
     def test_comparison(self):
-        acu = code_unit_factory("aa/afile.py", FileLocator())[0]
-        acu2 = code_unit_factory("aa/afile.py", FileLocator())[0]
-        zcu = code_unit_factory("aa/zfile.py", FileLocator())[0]
-        bcu = code_unit_factory("aa/bb/bfile.py", FileLocator())[0]
+        acu = code_unit_factory("aa/afile.py", FileLocator())
+        acu2 = code_unit_factory("aa/afile.py", FileLocator())
+        zcu = code_unit_factory("aa/zfile.py", FileLocator())
+        bcu = code_unit_factory("aa/bb/bfile.py", FileLocator())
         assert acu == acu2 and acu <= acu2 and acu >= acu2
         assert acu < zcu and acu <= zcu and acu != zcu
         assert zcu > acu and zcu >= acu and zcu != acu
@@ -108,6 +108,6 @@ class CodeUnitTest(CoverageTest):
         # in the path is actually the .egg zip file.
         self.assert_doesnt_exist(egg1.__file__)
 
-        cu = code_unit_factory([egg1, egg1.egg1], FileLocator())
+        cu = code_units_factory([egg1, egg1.egg1], FileLocator())
         self.assertEqual(cu[0].source(), u"")
         self.assertEqual(cu[1].source().split("\n")[0], u"# My egg file!")