Merge pull request RustPython#1026 from rmliddle/BytesIO

String/BytesIO

Author: windelbouwman

README.md

@@ -197,7 +197,7 @@ crate and webpack.
 
 # Code style
 
-The code style used is the default rustfmt codestyle. Please format your code accordingly.
+The code style used is the default [rustfmt](https://github.com/rust-lang/rustfmt) codestyle. Please format your code accordingly.
 
 # Community
 

tests/snippets/bytes_io.py

@@ -0,0 +1,50 @@
+
+from io import BytesIO
+
+def test_01():
+    bytes_string =  b'Test String 1'
+
+    f = BytesIO()
+    f.write(bytes_string)
+
+    assert f.getvalue() == bytes_string
+
+def test_02():
+    bytes_string =  b'Test String 2'
+    f = BytesIO(bytes_string)
+
+    assert f.read() == bytes_string
+    assert f.read() == b''
+
+def test_03():
+    """
+        Tests that the read method (integer arg)
+        returns the expected value
+    """
+    string =  b'Test String 3'
+    f = BytesIO(string)
+
+    assert f.read(1) == b'T'
+    assert f.read(1) == b'e'
+    assert f.read(1) == b's'
+    assert f.read(1) == b't'
+
+def test_04():
+    """
+        Tests that the read method increments the 
+        cursor position and the seek method moves 
+        the cursor to the appropriate position
+    """
+    string =  b'Test String 4'
+    f = BytesIO(string)
+
+    assert f.read(4) == b'Test'
+    assert f.seek(0) == 0
+    assert f.read(4) == b'Test'
+
+if __name__ == "__main__":
+    test_01()
+    test_02()
+    test_03()
+    test_04()
+

tests/snippets/string_io.py

@@ -0,0 +1,56 @@
+
+from io import StringIO
+
+def test_01():
+    """
+        Test that the constructor and getvalue
+        method return expected values
+    """
+    string =  'Test String 1'
+    f = StringIO()
+    f.write(string)
+
+    assert f.getvalue() == string
+
+def test_02():
+    """
+        Test that the read method (no arg)
+        results the expected value
+    """
+    string =  'Test String 2'
+    f = StringIO(string)
+
+    assert f.read() == string
+    assert f.read() == ''
+
+def test_03():
+    """
+        Tests that the read method (integer arg)
+        returns the expected value
+    """
+    string =  'Test String 3'
+    f = StringIO(string)
+
+    assert f.read(1) == 'T'
+    assert f.read(1) == 'e'
+    assert f.read(1) == 's'
+    assert f.read(1) == 't'
+
+def test_04():
+    """
+        Tests that the read method increments the 
+        cursor position and the seek method moves 
+        the cursor to the appropriate position
+    """
+    string =  'Test String 4'
+    f = StringIO(string)
+
+    assert f.read(4) == 'Test'
+    assert f.seek(0) == 0
+    assert f.read(4) == 'Test'
+
+if __name__ == "__main__":
+    test_01()
+    test_02()
+    test_03()
+    test_04()