Backport changes from branch py3-StringIO-perf

1 files changed, 54 insertions, 0 deletions

diff --git a/extra_tests/test_stringio.py b/extra_tests/test_stringio.py
new file mode 100644
index 0000000000..040e91a4a2
--- /dev/null
+++ b/extra_tests/test_stringio.py
@@ -0,0 +1,54 @@
+from hypothesis import given, strategies as st
+
+from io import StringIO
+from os import linesep
+
+LINE_ENDINGS = [u'\n', u'\r', u'\r\n']
+
+@given(txt=st.text(), newline=st.sampled_from(['', '\n']))
+def test_simple(txt, newline):
+    sio = StringIO(txt, newline=newline)
+    assert sio.getvalue() == txt
+
+@given(values=st.lists(
+    st.tuples(
+        st.text(st.characters(blacklist_characters='\r\n'), min_size=1),
+        st.sampled_from(LINE_ENDINGS))))
+def test_universal(values):
+    output_lines = [line + linesep for line, ending in values]
+    output = u''.join(output_lines)
+
+    input = u''.join(line + ending for line, ending in values)
+    sio = StringIO(input, newline=None)
+    sio.seek(0)
+    assert list(sio) == output_lines
+    assert sio.getvalue() == output
+
+    sio2 = StringIO(newline=None)
+    for line, ending in values:
+        sio2.write(line)
+        sio2.write(ending)
+    sio2.seek(0)
+    assert list(sio2) == output_lines
+    assert sio2.getvalue() == output
+
+@given(
+    lines=st.lists(st.text(st.characters(blacklist_characters='\r\n'))),
+    newline=st.sampled_from(['\r', '\r\n']))
+def test_crlf(lines, newline):
+    output_lines = [line + newline for line in lines]
+    output = u''.join(output_lines)
+
+    input = u''.join(line + '\n' for line in lines)
+    sio = StringIO(input, newline=newline)
+    sio.seek(0)
+    assert list(sio) == output_lines
+    assert sio.getvalue() == output
+
+    sio2 = StringIO(newline=newline)
+    for line in lines:
+        sio2.write(line)
+        sio2.write(u'\n')
+    sio2.seek(0)
+    assert list(sio2) == output_lines
+    assert sio2.getvalue() == ''.join(output_lines)