message.content -> .raw_content, implement .text

This PR improves our handling of HTTP message body encodings:

- The unaltered message body is now accessible as `.raw_content`
- The "content-encoding"-decoded content (i.e. gzip removed) content
  is not `.content`, as this is what we want in 99% of the cases.
- `.text` now provides the "content-encoding"-decoded and then
  "content-type charset"-decoded message body.
- The decoded values for `.content` and `.text` are cached,
  so that repeated access and `x.text = x.text` is cheap.
- The `decoded()` decorator is now deprecated, as we can now just use
  `.content`. Similarly `HTTPMessage.get_decoded_content()` is
  deprecated.

1 files changed, 21 insertions, 19 deletions

diff --git a/test/netlib/test_encoding.py b/test/netlib/test_encoding.py
index 0ff1aad1..de10fc48 100644
--- a/test/netlib/test_encoding.py
+++ b/test/netlib/test_encoding.py
@@ -1,37 +1,39 @@
-from netlib import encoding
+from netlib import encoding, tutils
 
 
 def test_identity():
-    assert b"string" == encoding.decode("identity", b"string")
-    assert b"string" == encoding.encode("identity", b"string")
-    assert not encoding.encode("nonexistent", b"string")
-    assert not encoding.decode("nonexistent encoding", b"string")
+    assert b"string" == encoding.decode(b"string", "identity")
+    assert b"string" == encoding.encode(b"string", "identity")
+    with tutils.raises(ValueError):
+        encoding.encode(b"string", "nonexistent encoding")
 
 
 def test_gzip():
     assert b"string" == encoding.decode(
-        "gzip",
         encoding.encode(
-            "gzip",
-            b"string"
-        )
+            b"string",
+            "gzip"
+        ),
+        "gzip"
     )
-    assert encoding.decode("gzip", b"bogus") is None
+    with tutils.raises(ValueError):
+        encoding.decode(b"bogus", "gzip")
 
 
 def test_deflate():
     assert b"string" == encoding.decode(
-        "deflate",
         encoding.encode(
-            "deflate",
-            b"string"
-        )
+            b"string",
+            "deflate"
+        ),
+        "deflate"
     )
     assert b"string" == encoding.decode(
-        "deflate",
         encoding.encode(
-            "deflate",
-            b"string"
-        )[2:-4]
+            b"string",
+            "deflate"
+        )[2:-4],
+        "deflate"
     )
-    assert encoding.decode("deflate", b"bogus") is None
+    with tutils.raises(ValueError):
+        encoding.decode(b"bogus", "deflate")