Allow hand-polishing individual exceptions by overriding templates. Fix #37.

.gitignore

@@ -5,9 +5,6 @@ __pycache__
 
 # Generated code
 /stubs/
-/fastly_compute/exceptions/*
-!/fastly_compute/exceptions/__init__.py
-/fastly_compute/runtime_patching/patches.py
 
 # Build artifacts
 /build/

Makefile

@@ -60,7 +60,7 @@ $(BUILD_DIR)/%.composed.wasm: wit/viceroy.wit wit/deps/fastly/compute.wit fastly
 # The script that writes the exceptions and the patches always rewrites
 # everything, so we can depend on the mod date of only 1 file. We choose
 # patches.py, because its name doesn't depend on the WIT contents.
-fastly_compute/runtime_patching/patches.py: scripts/generate_patches/*.py $(COMPUTE_WIT)
+fastly_compute/runtime_patching/patches.py: scripts/generate_patches/*.py $(shell find scripts/generate_patches/templates -name "*.jinja") $(COMPUTE_WIT)
 	uv run python -m scripts.generate_patches
 
 # Create build directory

fastly_compute/exceptions/acl/__init__.py

@@ -0,0 +1,4 @@
+"""Blocklists using [Access Control Lists] (ACLs)
+
+[Access Control Lists]: https://www.fastly.com/documentation/reference/api/acls/
+"""

fastly_compute/exceptions/acl/acl_error.py

@@ -0,0 +1,23 @@
+# This file is automatically generated by generate_patches.
+# It is not intended for manual editing.
+"""Errors returned on ACL lookup failure."""
+
+from fastly_compute.exceptions import FastlyError
+
+
+class AclError(FastlyError):
+    """Errors returned on ACL lookup failure."""
+
+
+class TooManyRequests(AclError):
+    """Too many requests have been made.
+
+    This corresponds to an HTTP error code of 429, “Too Many Requests”.
+    """
+
+
+class GenericError(AclError):
+    """Generic error value.
+
+    This means that some unexpected error occurred.
+    """

fastly_compute/exceptions/http_body/__init__.py

@@ -0,0 +1 @@
+"""HTTP bodies."""

fastly_compute/exceptions/http_body/trailer_error.py

@@ -0,0 +1,21 @@
+# This file is automatically generated by generate_patches.
+# It is not intended for manual editing.
+"""Trailers aren't available until the body has been completely transmitted, so this error
+type can either indicate that the errors aren't available yet, or that an error occurred.
+"""
+
+from fastly_compute.exceptions import FastlyError
+
+
+class TrailerError(FastlyError):
+    """Trailers aren't available until the body has been completely transmitted, so this error
+    type can either indicate that the errors aren't available yet, or that an error occurred.
+    """
+
+
+class NotAvailableYet(TrailerError):
+    """The trailers aren't available yet."""
+
+
+class Error(TrailerError):
+    """An error occurred."""

fastly_compute/exceptions/http_req/__init__.py

@@ -0,0 +1,9 @@
+# This file is automatically generated by generate_patches.
+# It is not intended for manual editing.
+"""An `error` code, optionally with extra request error information."""
+
+from fastly_compute.exceptions import FastlyError
+
+
+class ErrorWithDetail(FastlyError):
+    """An `error` code, optionally with extra request error information."""

fastly_compute/exceptions/kv_store/__init__.py

@@ -0,0 +1,7 @@
+"""Interface to Fastly's [Compute KV Store].
+
+For a high-level introduction to this feature, see this [blog post].
+
+[Compute KV Store]: https://www.fastly.com/documentation/guides/concepts/edge-state/data-stores/#kv-stores
+[blog post]: https://www.fastly.com/blog/introducing-the-compute-edge-kv-store-global-persistent-storage-for-compute-functions
+"""

fastly_compute/exceptions/kv_store/kv_error.py

@@ -0,0 +1,57 @@
+# This file is automatically generated by generate_patches.
+# It is not intended for manual editing.
+"""A value indicating the status of a KV store operation."""
+
+from fastly_compute.exceptions import FastlyError
+
+
+class KvError(FastlyError):
+    """A value indicating the status of a KV store operation."""
+
+
+class BadRequest(KvError):
+    """KV store cannot or will not process the request due to something that is perceived to be a
+    client error.
+
+    This will map to the api's 400 codes.
+    """
+
+
+class PreconditionFailed(KvError):
+    """KV store cannot fulfill the request, as defined by the client's prerequisites, for example
+    `if-generation-match`.
+
+    This will map to the api's 412 codes.
+    """
+
+
+class PayloadTooLarge(KvError):
+    """The size limit for a KV store key was exceeded.
+
+    This will map to the api's 413 codes.
+    """
+
+
+class InternalError(KvError):
+    """The system encountered an unexpected internal error.
+
+    This will map to all remaining http error codes.
+    """
+
+
+class TooManyRequests(KvError):
+    """Too many requests have been made to the KV store.
+
+    This will map to the api's 429 codes.
+    """
+
+
+class GenericError(KvError):
+    """Generic error value.
+
+    This means that some unexpected error occurred.
+    """
+
+
+class Extra(KvError):
+    """Additional error information may be added in the future via this resource type."""

fastly_compute/exceptions/types/__init__.py

@@ -0,0 +1 @@
+"""Types used by many interfaces in this package."""

fastly_compute/exceptions/types/error.py

@@ -0,0 +1,116 @@
+# This file is automatically generated by generate_patches.
+# It is not intended for manual editing.
+"""A common error type used by many functions in this package.
+
+TODO: In the future this should be split up into more-specific error
+enums so that it better documents which errors each function can actually
+return and what they mean.
+"""
+
+from fastly_compute.exceptions import FastlyError
+
+
+class Error(FastlyError):
+    """A common error type used by many functions in this package.
+
+    TODO: In the future this should be split up into more-specific error
+    enums so that it better documents which errors each function can actually
+    return and what they mean.
+    """
+
+
+class GenericError(Error):
+    """Generic error value.
+
+    This means that some unexpected error occurred.
+    """
+
+
+class InvalidArgument(Error):
+    """Invalid argument."""
+
+
+class AuxiliaryError(Error):
+    """Auxiliary error value.
+
+    For `cache.get-body` and `cache.replace-get-body`, it means the cache implementation was
+    busy and not ready to retrieve the body data.
+
+    For cache APIs that attempt to write to or update the body of a cache transaction, it means
+    that an error occurred while attempting the write or update.
+
+    For other cache APIs, it indicates that the underlying cache entry or cache replace entry
+    is no longer available.
+
+    For writing to a streaming HTTP body, indicates that the body has already been closed.
+
+    For a dictionary lookup, indicates that the dictionary was not found.
+    """
+
+
+class Unsupported(Error):
+    """Unsupported operation error.
+
+    This error is returned when some operation cannot be performed, because it is not supported.
+    """
+
+
+class HttpInvalid(Error):
+    """Invalid HTTP error.
+
+    This can be returned when a method, URI, header, or status is not valid. This can also
+    be returned if a message head is too large.
+    """
+
+
+class HttpUser(Error):
+    """HTTP user error.
+
+    This is returned in cases where user code caused an HTTP error. For example, attempt to send
+    a 1xx response code, or a request with a non-absolute URI. This can also be caused by
+    an unexpected header: both `content-length` and `transfer-encoding`, for example.
+    """
+
+
+class HttpIncomplete(Error):
+    """HTTP incomplete message error.
+
+    This can be returned when a stream ended unexpectedly.
+    """
+
+
+class CannotRead(Error):
+    """Cannot read.
+
+    An error occurred while attempting to read the body of a cache transaction.
+    """
+
+
+class HttpHeadTooLarge(Error):
+    """Message head too large."""
+
+
+class HttpInvalidStatus(Error):
+    """Invalid HTTP status."""
+
+
+class LimitExceeded(Error):
+    """Limit exceeded
+
+    This is returned when an attempt to allocate a resource has exceeded the maximum number of
+    resources permitted. For example, creating too many response handles.
+    """
+
+
+class BufferLen(Error):
+    """Buffer length error
+
+    Returned when a buffer is the wrong size.
+    Includes the buffer length that would allow the operation to succeed.
+    """
+
+    def __init__(self, wit_error):
+        self.length = wit_error.value
+
+    def __str__(self):
+        return f"Buffer was too short to hold the result. At least {self.length} bytes are needed."

fastly_compute/exceptions/types/open_error.py

@@ -0,0 +1,47 @@
+# This file is automatically generated by generate_patches.
+# It is not intended for manual editing.
+"""An error returned by `open`-like functions."""
+
+from fastly_compute.exceptions import FastlyError
+
+
+class OpenError(FastlyError):
+    """An error returned by `open`-like functions."""
+
+
+class InvalidSyntax(OpenError):
+    """The given name of the entity to open was invalid."""
+
+
+class NameTooLong(OpenError):
+    """The given name is longer the maximum permitted length."""
+
+
+class Reserved(OpenError):
+    """The given name is a reserved name that may not be opened."""
+
+
+class NotFound(OpenError):
+    """No entity by the given name was found."""
+
+
+class Unsupported(OpenError):
+    """Unsupported operation error.
+
+    This error is returned when some operation cannot be performed, because it is not supported.
+    """
+
+
+class LimitExceeded(OpenError):
+    """Limit exceeded
+
+    This is returned when an attempt to allocate a resource has exceeded the maximum number of
+    resources permitted. For example, creating too many response handles.
+    """
+
+
+class GenericError(OpenError):
+    """Generic error value.
+
+    This means that some unexpected error occurred.
+    """