tests/io: Improve test coverage of io.BufferedWriter.

tests/io/buffered_writer.py

@@ -20,3 +20,9 @@ buf.flush()
 print(bts.getvalue())
 buf.flush()
 print(bts.getvalue())
+
+# special case when alloc is a factor of total buffer length
+bts = io.BytesIO()
+buf = io.BufferedWriter(bts, 1)
+buf.write(b"foo")
+print(bts.getvalue())

tests/io/buffered_writer.py.exp

@@ -2,3 +2,4 @@ b''
 b'foobarfo'
 b'foobarfoobar'
 b'foobarfoobar'
+b'foo'

tests/unix/extra_coverage.py

@@ -6,6 +6,7 @@ except NameError:
     sys.exit()
 
 import uerrno
+import uio
 
 data = extra_coverage()
 
@@ -45,6 +46,11 @@ except OSError:
     print('OSError')
 print(stream2.read(1)) # read 1 byte encounters non-blocking error with textio stream
 
+# test BufferedWriter with stream errors
+stream.set_error(uerrno.EAGAIN)
+buf = uio.BufferedWriter(stream, 8)
+print(buf.write(bytearray(16)))
+
 # test basic import of frozen scripts
 import frzstr1
 import frzmpy1

tests/unix/extra_coverage.py.exp

@@ -61,6 +61,7 @@ OSError
 0
 OSError
 None
+None
 frzstr1
 frzmpy1
 frzstr_pkg1.__init__