Merge ~cjwatson/lazr.restful:remove-six into lazr.restful:main

[Colin Watson]

Remove remaining uses of six

[Jürgen Gmach (jugmac00)]

It is a bit unfortunate that we do not run coverage for this project (and all projects).

Some occurrences of `six.ensure_str` were just removed, some were replaced by xxx.decode().

I cannot say whether this is correct or not.

I quickly tried to setup coverage for the review, the tests ran, but got a "no data collected" error :-/

```
[testenv]
deps =
    .[test,xml]
    zope.testrunner
    coverage
commands =
    coverage run -m zope.testrunner --test-path src --tests-pattern ^tests {posargs}
    coverage report -m
```

I have no clue what is going wrong here.

[Colin Watson (cjwatson)]

All but one of the `six.ensure_*` calls that I removed are themselves in test code, so it's fairly easy to see that they're covered. The one exception is in `lazr.restful.declarations._versioned_class_name`, which is called by `lazr.restful.declarations.generate_*`. For removing `six.ensure_str` to be a problem there, somebody would have to have explicitly included a bytes item in their `IWebServiceConfiguration.active_versions`, which is declared as a list of `TextLine`; so I don't think this can be a problem.

Coverage seems to work fine for me, but declaring `coverage:run` would help so that it doesn't try to consider coverage of all dependencies as well. I'll propose a separate branch to set up coverage.

[Jürgen Gmach (jugmac00)]

Would you please rebase this MP on current main so includes the coverage env?

[Colin Watson (cjwatson)]

Done.

[Jürgen Gmach (jugmac00)]

review: Approve

diff --git a/setup.py b/setup.py
index 1017963..c21f37a 100755
--- a/setup.py
+++ b/setup.py
@@ -62,7 +62,6 @@ setup(
         "pytz",
         "setuptools",
         "simplejson>=2.1.0",
-        "six>=1.13.0",
         "testtools",
         "van.testing",
         "zope.component [zcml]",
diff --git a/src/lazr/restful/debug.py b/src/lazr/restful/debug.py
index ebcf526..3dfb865 100644
--- a/src/lazr/restful/debug.py
+++ b/src/lazr/restful/debug.py
@@ -4,10 +4,9 @@
 
 __all__ = ["debug_proxy", "typename"]
 
+from io import StringIO
 
-from six import StringIO
 import zope.proxy
-
 from zope.security.checker import getChecker, Checker, CheckerPublic, Proxy
 
 
diff --git a/src/lazr/restful/declarations.py b/src/lazr/restful/declarations.py
index 0fca6c1..ecfcc00 100644
--- a/src/lazr/restful/declarations.py
+++ b/src/lazr/restful/declarations.py
@@ -44,7 +44,6 @@ import copy
 import itertools
 import sys
 
-import six
 from zope.component import getUtility, getGlobalSiteManager
 from zope.interface import classImplements
 from zope.interface.interface import fromFunction, InterfaceClass, TAGGED_DATA
@@ -1943,5 +1942,5 @@ def _versioned_class_name(base_name, version):
         # runtime. Use a generic string that won't conflict with a
         # real version string.
         version = "__Earliest"
-    name = "%s_%s" % (base_name, six.ensure_str(version))
+    name = "%s_%s" % (base_name, version)
     return make_identifier_safe(name)
diff --git a/src/lazr/restful/docs/webservice.rst b/src/lazr/restful/docs/webservice.rst
index 411d9e8..d10d4a3 100644
--- a/src/lazr/restful/docs/webservice.rst
+++ b/src/lazr/restful/docs/webservice.rst
@@ -1088,9 +1088,8 @@ top-level collections of authors, cookbooks, and dishes. It's the
 'home page' for the web service.
 
     >>> import simplejson
-    >>> import six
     >>> response = app(request)
-    >>> representation = simplejson.loads(six.ensure_text(response))
+    >>> representation = simplejson.loads(response)
 
     >>> print(representation["authors_collection_link"])
     http://api.cookbooks.dev/beta/authors
@@ -1165,7 +1164,7 @@ parsed with standard tools.
 
     >>> def load_json(s):
     ...     """Convert a JSON string to Unicode and then load it."""
-    ...     return simplejson.loads(six.ensure_text(s))
+    ...     return simplejson.loads(s)
 
     >>> representation = load_json(collection())
     >>> print(representation['resource_type_link'])
@@ -1678,7 +1677,9 @@ easily accessible data structure.
     ...         headers['HTTP_IF_NONE_MATCH'] = etag
     ...     get_request = create_web_service_request(
     ...         julia_url, environ=headers)
-    ...     entity_body = six.ensure_text(get_request.traverse(app)())
+    ...     entity_body = get_request.traverse(app)()
+    ...     if isinstance(entity_body, bytes):
+    ...         entity_body = entity_body.decode()
     ...     return dict(entity_body=entity_body,
     ...                 response=get_request.response)
 
@@ -1820,7 +1821,7 @@ set the field value to 'tag:launchpad.net:2008:redacted'.
     >>> body = simplejson.dumps(author).encode()
     >>> put_request = create_web_service_request(
     ...     beard_url, body=body, environ=headers, method='PUT')
-    >>> print(six.ensure_text(put_request.traverse(app)()))
+    >>> print(put_request.traverse(app)().decode())
     {...}
 
 And since no special permission is necessary to _change_ a person's
@@ -1833,7 +1834,7 @@ PUT, even when its current value is redacted.
     >>> body = simplejson.dumps(author).encode()
     >>> put_request = create_web_service_request(
     ...     beard_url, body=body, environ=headers, method='PUT')
-    >>> print(six.ensure_text(put_request.traverse(app)()))
+    >>> print(put_request.traverse(app)().decode())
     {...}
 
 After that PUT, James Beard's 'favorite_recipe' attribute is no longer
@@ -1897,7 +1898,7 @@ A cookbook can be given a cover with PUT.
     >>> file_resource = put_request.traverse(app)
     >>> file_resource()
 
-    >>> print(six.ensure_str(C2.cover.representation))
+    >>> print(C2.cover.representation.decode())
     Pretend...
 
 At this point it exists:
@@ -1934,7 +1935,7 @@ An entry's primitive data fields are exposed as subordinate resources.
 
     >>> field_resource = create_web_service_request(
     ...     '/beta/cookbooks/The%20Joy%20of%20Cooking/name').traverse(app)
-    >>> print(six.ensure_text(field_resource()))
+    >>> print(field_resource().decode())
     "The Joy of Cooking"
 
 Requesting non available resources
@@ -2059,7 +2060,10 @@ their URLs, we make the change by modifying the cookbook's
     ...         '/beta/cookbooks/The%20Joy%20of%20Cooking',
     ...         body=simplejson.dumps(representation).encode(),
     ...         environ=headers, method='PATCH', hostname=host).traverse(app)
-    ...     return six.ensure_text(resource())
+    ...     result = resource()
+    ...     if isinstance(result, bytes):
+    ...         result = result.decode()
+    ...     return result
     >>> path = '/beta/authors/Julia%20Child'
 
     >>> print(change_joy_author('http://api.cookbooks.dev' + path))
@@ -2122,7 +2126,7 @@ Now you see it...
 
     >>> resource = create_web_service_request(
     ...     recipe_url, method='GET').traverse(app)
-    >>> print(six.ensure_text(resource()))
+    >>> print(resource().decode())
     {...}
 
     >>> resource = create_web_service_request(
diff --git a/src/lazr/restful/example/base/tests/collection.txt b/src/lazr/restful/example/base/tests/collection.txt
index e156a43..44065aa 100644
--- a/src/lazr/restful/example/base/tests/collection.txt
+++ b/src/lazr/restful/example/base/tests/collection.txt
@@ -325,8 +325,6 @@ POST operations may involve text fields.  These are marshalled via a
 multipart/form-data request, which requires line breaks to be represented as
 CRLF.  The server turns these into Unix-style LF.
 
-    >>> import six
-
     >>> def create_recipe(id, cookbook_link, dish_link, instructions,
     ...                   private=False):
     ...     return webservice.named_post(
@@ -344,6 +342,6 @@ CRLF.  The server turns these into Unix-style LF.
     >>> response.status
     201
     >>> recipe = webservice.get(response.getHeader("Location")).jsonBody()
-    >>> six.ensure_str(recipe["instructions"])
+    >>> recipe["instructions"]
     'Recipe\ncontaining\nsome\nline\n\nbreaks'
     >>> _ = webservice.delete(recipe["self_link"])
diff --git a/src/lazr/restful/example/base/tests/entry.txt b/src/lazr/restful/example/base/tests/entry.txt
index f24c7a3..decab39 100644
--- a/src/lazr/restful/example/base/tests/entry.txt
+++ b/src/lazr/restful/example/base/tests/entry.txt
@@ -118,9 +118,7 @@ a simple definition list.
 Getting the XHTML representation works correctly even when some of the fields
 have non-ascii values.
 
-    >>> import six
-    >>> print(six.text_type(
-    ...     webservice.get(construsions_url, 'application/xhtml+xml')))
+    >>> print(str(webservice.get(construsions_url, 'application/xhtml+xml')))
     HTTP/1.1 200 Ok
     ...
     <dl ...>
diff --git a/src/lazr/restful/testing/helpers.py b/src/lazr/restful/testing/helpers.py
index c0dd63c..bfd8685 100644
--- a/src/lazr/restful/testing/helpers.py
+++ b/src/lazr/restful/testing/helpers.py
@@ -1,7 +1,6 @@
 import sys
 from types import ModuleType
 
-import six
 from zope.configuration import xmlconfig
 from zope.interface import implementer
 
@@ -63,7 +62,7 @@ def encode_unicode(unicode_string):
 
     :param unicode_string: A Unicode string.
     """
-    return six.ensure_str(unicode_string.encode("ascii", "backslashreplace"))
+    return unicode_string.encode("ascii", "backslashreplace").decode()
 
 
 @implementer(IWebServiceConfiguration)
diff --git a/src/lazr/restful/testing/webservice.py b/src/lazr/restful/testing/webservice.py
index 97bbc11..af7496b 100644
--- a/src/lazr/restful/testing/webservice.py
+++ b/src/lazr/restful/testing/webservice.py
@@ -34,7 +34,6 @@ from urllib.parse import (
 
 import wsgi_intercept
 
-import six
 from zope.component import adapter, getGlobalSiteManager, getUtility
 from zope.configuration import xmlconfig
 from zope.interface import alsoProvides, implementer, Interface
@@ -316,8 +315,8 @@ class WebServiceCaller:
         headers=None,
         api_version=None,
     ):
-        if isinstance(path_or_url, (bytes, str)):
-            path_or_url = six.ensure_str(path_or_url)
+        if isinstance(path_or_url, bytes):
+            path_or_url = path_or_url.decode()
         else:
             path_or_url = str(path_or_url)
         if path_or_url.startswith("/"):
@@ -459,9 +458,9 @@ class WebServiceCaller:
                     value = simplejson.dumps(value)
                 lines = re.split(r"\r\n|\r|\n", value)
                 for line in lines[:-1]:
-                    buf.write(six.ensure_binary(line))
+                    buf.write(line.encode())
                     buf.write(b"\r\n")
-                buf.write(six.ensure_binary(lines[-1]))
+                buf.write(lines[-1].encode())
             encoded_parts.append(buf.getvalue())
 
         # Create a suitable boundary.
@@ -580,7 +579,9 @@ class WebServiceResponseWrapper(ProxyBase):
 
     def jsonBody(self):
         """Return the body of the web service request as a JSON document."""
-        body = six.ensure_text(self.body)
+        body = self.body
+        if isinstance(body, bytes):
+            body = body.decode()
         try:
             return simplejson.loads(body, object_pairs_hook=OrderedDict)
         except ValueError: