init

.env/lib/python3.10/site-packages/flask/debughelpers.py

@@ -0,0 +1,158 @@
+import typing as t
+
+from .app import Flask
+from .blueprints import Blueprint
+from .globals import request_ctx
+
+
+class UnexpectedUnicodeError(AssertionError, UnicodeError):
+    """Raised in places where we want some better error reporting for
+    unexpected unicode or binary data.
+    """
+
+
+class DebugFilesKeyError(KeyError, AssertionError):
+    """Raised from request.files during debugging.  The idea is that it can
+    provide a better error message than just a generic KeyError/BadRequest.
+    """
+
+    def __init__(self, request, key):
+        form_matches = request.form.getlist(key)
+        buf = [
+            f"You tried to access the file {key!r} in the request.files"
+            " dictionary but it does not exist. The mimetype for the"
+            f" request is {request.mimetype!r} instead of"
+            " 'multipart/form-data' which means that no file contents"
+            " were transmitted. To fix this error you should provide"
+            ' enctype="multipart/form-data" in your form.'
+        ]
+        if form_matches:
+            names = ", ".join(repr(x) for x in form_matches)
+            buf.append(
+                "\n\nThe browser instead transmitted some file names. "
+                f"This was submitted: {names}"
+            )
+        self.msg = "".join(buf)
+
+    def __str__(self):
+        return self.msg
+
+
+class FormDataRoutingRedirect(AssertionError):
+    """This exception is raised in debug mode if a routing redirect
+    would cause the browser to drop the method or body. This happens
+    when method is not GET, HEAD or OPTIONS and the status code is not
+    307 or 308.
+    """
+
+    def __init__(self, request):
+        exc = request.routing_exception
+        buf = [
+            f"A request was sent to '{request.url}', but routing issued"
+            f" a redirect to the canonical URL '{exc.new_url}'."
+        ]
+
+        if f"{request.base_url}/" == exc.new_url.partition("?")[0]:
+            buf.append(
+                " The URL was defined with a trailing slash. Flask"
+                " will redirect to the URL with a trailing slash if it"
+                " was accessed without one."
+            )
+
+        buf.append(
+            " Send requests to the canonical URL, or use 307 or 308 for"
+            " routing redirects. Otherwise, browsers will drop form"
+            " data.\n\n"
+            "This exception is only raised in debug mode."
+        )
+        super().__init__("".join(buf))
+
+
+def attach_enctype_error_multidict(request):
+    """Patch ``request.files.__getitem__`` to raise a descriptive error
+    about ``enctype=multipart/form-data``.
+
+    :param request: The request to patch.
+    :meta private:
+    """
+    oldcls = request.files.__class__
+
+    class newcls(oldcls):
+        def __getitem__(self, key):
+            try:
+                return super().__getitem__(key)
+            except KeyError as e:
+                if key not in request.form:
+                    raise
+
+                raise DebugFilesKeyError(request, key).with_traceback(
+                    e.__traceback__
+                ) from None
+
+    newcls.__name__ = oldcls.__name__
+    newcls.__module__ = oldcls.__module__
+    request.files.__class__ = newcls
+
+
+def _dump_loader_info(loader) -> t.Generator:
+    yield f"class: {type(loader).__module__}.{type(loader).__name__}"
+    for key, value in sorted(loader.__dict__.items()):
+        if key.startswith("_"):
+            continue
+        if isinstance(value, (tuple, list)):
+            if not all(isinstance(x, str) for x in value):
+                continue
+            yield f"{key}:"
+            for item in value:
+                yield f"  - {item}"
+            continue
+        elif not isinstance(value, (str, int, float, bool)):
+            continue
+        yield f"{key}: {value!r}"
+
+
+def explain_template_loading_attempts(app: Flask, template, attempts) -> None:
+    """This should help developers understand what failed"""
+    info = [f"Locating template {template!r}:"]
+    total_found = 0
+    blueprint = None
+    if request_ctx and request_ctx.request.blueprint is not None:
+        blueprint = request_ctx.request.blueprint
+
+    for idx, (loader, srcobj, triple) in enumerate(attempts):
+        if isinstance(srcobj, Flask):
+            src_info = f"application {srcobj.import_name!r}"
+        elif isinstance(srcobj, Blueprint):
+            src_info = f"blueprint {srcobj.name!r} ({srcobj.import_name})"
+        else:
+            src_info = repr(srcobj)
+
+        info.append(f"{idx + 1:5}: trying loader of {src_info}")
+
+        for line in _dump_loader_info(loader):
+            info.append(f"       {line}")
+
+        if triple is None:
+            detail = "no match"
+        else:
+            detail = f"found ({triple[1] or '<string>'!r})"
+            total_found += 1
+        info.append(f"       -> {detail}")
+
+    seems_fishy = False
+    if total_found == 0:
+        info.append("Error: the template could not be found.")
+        seems_fishy = True
+    elif total_found > 1:
+        info.append("Warning: multiple loaders returned a match for the template.")
+        seems_fishy = True
+
+    if blueprint is not None and seems_fishy:
+        info.append(
+            "  The template was looked up from an endpoint that belongs"
+            f" to the blueprint {blueprint!r}."
+        )
+        info.append("  Maybe you did not place a template in the right folder?")
+        info.append("  See https://flask.palletsprojects.com/blueprints/#templates")
+
+    app.logger.info("\n".join(info))