Fix line-by-line file iteration in ioutils modules

- iterator on self was yielding only the first newline
- added __next__ to match next() for py3 compat
- updated tests

boltons/ioutils.py

@@ -116,7 +116,15 @@ class SpooledIOBase(object):
         return self.buffer.isatty()
 
     def next(self):
-        return self.readline()
+        line = self.readline()
+        if not line:
+            pos = self.buffer.tell()
+            self.buffer.seek(0, os.SEEK_END)
+            if pos == self.buffer.tell():
+                raise StopIteration
+            else:
+                self.buffer.seek(pos)
+        return line
 
     @property
     def closed(self):
@@ -161,11 +169,13 @@ class SpooledIOBase(object):
         self.seek(pos)
         return val
 
+    __next__ = next
+
     def __len__(self):
         return self.len
 
     def __iter__(self):
-        yield self.readline()
+        return self
 
     def __enter__(self):
         return self

tests/test_ioutils.py

@@ -142,13 +142,6 @@ class BaseTestMixin(object):
         self.spooled_flo.softspace = True
         self.assertTrue(self.spooled_flo.softspace)
 
-    def test_iter(self):
-        """Make sure iter works as expected"""
-        self.spooled_flo.write(self.test_str)
-        self.spooled_flo.seek(0)
-        self.assertEqual([x for x in self.spooled_flo][0], self.test_str)
-        self.assertEqual([x for x in self.spooled_flo][0], self.data_type())
-
     def test_buf_property(self):
         """'buf' property returns the same value as getvalue()"""
         self.assertEqual(self.spooled_flo.buf, self.spooled_flo.getvalue())
@@ -273,6 +266,12 @@ class TestSpooledBytesIO(TestCase, BaseTestMixin, AssertionsMixin):
         self.assertTrue('content.txt' in doc.namelist())
         doc.close()
 
+    def test_iter(self):
+        """Make sure iter works as expected"""
+        self.spooled_flo.write(b"a\nb")
+        self.spooled_flo.seek(0)
+        self.assertEqual([x for x in self.spooled_flo], [b"a\n", b"b"])
+
 
 class TestSpooledStringIO(TestCase, BaseTestMixin, AssertionsMixin):
     linesep = os.linesep
@@ -405,6 +404,12 @@ class TestSpooledStringIO(TestCase, BaseTestMixin, AssertionsMixin):
         self.spooled_flo.seek(0)
         self.assertEqual(self.spooled_flo.read(3), test_str)
 
+    def test_iter(self):
+        """Make sure iter works as expected"""
+        self.spooled_flo.write(u"a\nb")
+        self.spooled_flo.seek(0)
+        self.assertEqual([x for x in self.spooled_flo], [u"a\n", u"b"])
+
 
 class TestMultiFileReader(TestCase):
     def test_read_seek_bytes(self):