Add transformer for request.xreadlines()

django_codemod/visitors/__init__.py

@@ -8,6 +8,7 @@
 )
 from .html import UnescapeEntitiesTransformer
 from .http import (
+    HttpRequestXReadLinesTransformer,
     HttpUrlQuotePlusTransformer,
     HttpUrlQuoteTransformer,
     HttpUrlUnQuotePlusTransformer,
@@ -41,6 +42,7 @@
     "FloatRangeFormFieldTransformer",
     "FloatRangeModelFieldTransformer",
     "ForceTextTransformer",
+    "HttpRequestXReadLinesTransformer",
     "HttpUrlQuotePlusTransformer",
     "HttpUrlQuoteTransformer",
     "HttpUrlUnQuotePlusTransformer",

django_codemod/visitors/http.py

@@ -1,5 +1,11 @@
-from django_codemod.constants import DJANGO_3_0, DJANGO_4_0
-from django_codemod.visitors.base import BaseFuncRenameTransformer
+from libcst import BaseExpression, Call
+from libcst import matchers as m
+
+from django_codemod.constants import DJANGO_2_0, DJANGO_3_0, DJANGO_4_0
+from django_codemod.visitors.base import (
+    BaseDjCodemodTransformer,
+    BaseFuncRenameTransformer,
+)
 
 
 class HttpUrlQuoteTransformer(BaseFuncRenameTransformer):
@@ -45,3 +51,30 @@ class IsSafeUrlTransformer(BaseFuncRenameTransformer):
     removed_in = DJANGO_4_0
     rename_from = "django.utils.http.is_safe_url"
     rename_to = "django.utils.http.url_has_allowed_host_and_scheme"
+
+
+class HttpRequestXReadLinesTransformer(BaseDjCodemodTransformer):
+    """Replace `HttpRequest.xreadlines()` by iterating over the request."""
+
+    deprecated_in = DJANGO_2_0
+    removed_in = DJANGO_3_0
+
+    # This should be conservative and only apply changes to:
+    # - variables called `request`/`req`
+    # - `request`/`req` attributes (e.g `self.request`/`view.req`...)
+    matcher = m.Call(
+        func=m.Attribute(
+            value=m.OneOf(
+                m.Name(value="request"),
+                m.Name(value="req"),
+                m.Attribute(attr=m.Name(value="request")),
+                m.Attribute(attr=m.Name(value="req")),
+            ),
+            attr=m.Name(value="xreadlines"),
+        )
+    )
+
+    def leave_Call(self, original_node: Call, updated_node: Call) -> BaseExpression:
+        if m.matches(updated_node, self.matcher):
+            return updated_node.func.value
+        return super().leave_Call(original_node, updated_node)

docs/codemods.md

@@ -33,17 +33,24 @@ Applied by passing the `--removed-in 3.0` or `--deprecated-in 2.0` option:
 
 -   Replaces `render_to_response()` by `render()` and add `request=None`
     as the first argument of `render()`.
--   Replaces `django.utils.lru_cache.lru_cache()` by the function it\'s
+-   Replaces `django.utils.lru_cache.lru_cache()` by the function it's
     an alias of: `functools.lru_cache()`.
--   Replaces `django.utils._os.abspathu()` by the function it\'s an
+-   Replaces `django.utils._os.abspathu()` by the function it's an
     alias of: `os.path.abspath()`.
 -   Replaces `django.utils.encoding.python_2_unicode_compatible()` by
-    the function it\'s an alias of: `six.python_2_unicode_compatible()`.
+    the function it's an alias of: `six.python_2_unicode_compatible()`.
 -   Replaces `django.utils.decorators.ContextDecorator` by the class
-    from the standard library it\'s an alias to
+    from the standard library it's an alias to
     `contextlib.ContextDecorator`.
 -   Replace `django.utils.decorators.available_attrs()` by its return
     value `functools.WRAPPER_ASSIGNMENTS`.
+-   Replace `HttpRequest.xreadlines()` by iterating over the request.
+
+    This codemodder is quite conservative and will only replace function 
+    calls on variables or attributes called `request` or `req`.
+
+    For example, it will fix `request.xreadlines()` or `self.request.xreadlines()` 
+    but not `r.xreadlines()`.
 
 Applied by passing the `--removed-in 3.0` or `--deprecated-in 2.1` option:
 

tests/test_cli.py

@@ -209,6 +209,7 @@ def test_deprecated_in_mapping():
             "AbsPathTransformer",
             "AvailableAttrsTransformer",
             "ContextDecoratorTransformer",
+            "HttpRequestXReadLinesTransformer",
             "LRUCacheTransformer",
             "RenderToResponseTransformer",
             "UnicodeCompatibleTransformer",
@@ -254,6 +255,7 @@ def test_removed_in_mapping():
             "AbsPathTransformer",
             "AvailableAttrsTransformer",
             "ContextDecoratorTransformer",
+            "HttpRequestXReadLinesTransformer",
             "InlineHasAddPermissionsTransformer",
             "LRUCacheTransformer",
             "RenderToResponseTransformer",

tests/visitors/test_http.py

@@ -1,4 +1,7 @@
+from parameterized import parameterized
+
 from django_codemod.visitors import (
+    HttpRequestXReadLinesTransformer,
     HttpUrlQuotePlusTransformer,
     HttpUrlQuoteTransformer,
     HttpUrlUnQuotePlusTransformer,
@@ -96,3 +99,64 @@ def test_simple_substitution(self) -> None:
             result = url_has_allowed_host_and_scheme('http://test.com/some-path', None)
         """
         self.assertCodemod(before, after)
+
+
+class TestHttpRequestXReadLinesTransformer(BaseVisitorTest):
+
+    transformer = HttpRequestXReadLinesTransformer
+
+    def test_noop_wrong_name(self) -> None:
+        """Don't replace calls for name other than `request` or `req`."""
+        before = after = """
+            for line in r.xreadlines():
+                print(line)
+        """
+        self.assertCodemod(before, after)
+
+    @parameterized.expand(["req", "request"])
+    def test_simple_substitution(self, variable_name) -> None:
+        before = f"""
+            for line in {variable_name}.xreadlines():
+                print(line)
+        """
+        after = f"""
+            for line in {variable_name}:
+                print(line)
+        """
+        self.assertCodemod(before, after)
+
+    @parameterized.expand(["req", "request"])
+    def test_substitution_class_attribute(self, attribute_name) -> None:
+        before = f"""
+            for line in self.{attribute_name}.xreadlines():
+                print(line)
+        """
+        after = f"""
+            for line in self.{attribute_name}:
+                print(line)
+        """
+        self.assertCodemod(before, after)
+
+    @parameterized.expand(["req", "request"])
+    def test_substitution_view_attribute(self, attribute_name) -> None:
+        before = f"""
+            for line in view.{attribute_name}.xreadlines():
+                print(line)
+        """
+        after = f"""
+            for line in view.{attribute_name}:
+                print(line)
+        """
+        self.assertCodemod(before, after)
+
+    @parameterized.expand(["req", "request"])
+    def test_substitution_nested_attribute(self, attribute_name) -> None:
+        before = f"""
+            for line in self.view.{attribute_name}.xreadlines():
+                print(line)
+        """
+        after = f"""
+            for line in self.view.{attribute_name}:
+                print(line)
+        """
+        self.assertCodemod(before, after)