UAT: `ResourceHandlerService._DefaultHandler` raises `NotImplementedError` for all CRUD operations — resources without explicit handlers fail at runtime #3709

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opened 2026-04-05 22:15:45 +00:00 by freemo · 0 comments

freemo commented

2026-04-05 22:15:45 +00:00

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Bug Report

What Was Tested

src/cleveragents/application/services/resource_handler_service.py _DefaultHandler class (lines 287-423) was analyzed for runtime behavior when a resource type has no handler or handler resolution fails.

Expected Behavior (from spec)

Resources should be accessible (read/write/list) through their handlers. When a resource type has no explicit handler, a reasonable default behavior should be provided — at minimum, the resolve() method should work for sandbox creation, and CRUD operations should either work or provide a meaningful error message.

Actual Behavior (from code analysis)

_DefaultHandler raises NotImplementedError for ALL CRUD and lifecycle operations:

def read(self, *, resource: Resource, path: str = "") -> Content:
    raise NotImplementedError("Default handler does not support read()")

def write(self, *, resource: Resource, path: str, data: bytes) -> WriteResult:
    raise NotImplementedError("Default handler does not support write()")

def delete(self, *, resource: Resource, path: str = "") -> DeleteResult:
    raise NotImplementedError("Default handler does not support delete()")

def list_children(self, *, resource: Resource) -> list[str]:
    raise NotImplementedError("Default handler does not support list_children()")

def diff(self, *, resource: Resource, other_location: str) -> DiffResult:
    raise NotImplementedError("Default handler does not support diff()")

def discover_children(self, *, resource: Resource) -> list[Resource]:
    raise NotImplementedError("Default handler does not support discover_children()")

def create_sandbox(self, ...) -> SandboxResult:
    raise NotImplementedError("Default handler does not support create_sandbox()")

def create_checkpoint(self, ...) -> CheckpointResult:
    raise NotImplementedError("Default handler does not support create_checkpoint()")

def rollback_to(self, ...) -> RollbackResult:
    raise NotImplementedError("Default handler does not support rollback_to()")

def project_access(self, ...) -> AccessResult:
    raise NotImplementedError("Default handler does not support project_access()")

The _DefaultHandler is used when:

A resource type has handler=None (e.g., all virtual types: file, directory, commit, branch, tag, tree)
Handler resolution fails (e.g., handler module not found)

This means all virtual resource types (which have handler=None) will raise NotImplementedError for any CRUD operation attempted through ResourceHandlerService.

Impact

All virtual resource types (file, directory, commit, branch, tag, tree, remote, submodule, symlink) will fail with NotImplementedError on any CRUD operation
Handler resolution failures silently fall back to _DefaultHandler which then raises NotImplementedError — the original error is lost
project_access() raises NotImplementedError — access control checks for resources will fail

Code Locations

src/cleveragents/application/services/resource_handler_service.py lines 287-423
Virtual types with handler=None: src/cleveragents/application/services/_resource_registry_virtual.py

Steps to Reproduce

Register a virtual resource (e.g., type file)
Attempt ResourceHandlerService.resolve_resource(resource, plan_id, slot_name) — succeeds (uses sandbox)
Attempt handler.read(resource=resource) — raises NotImplementedError

Automated by CleverAgents Bot
Supervisor: UAT Testing | Agent: ca-uat-tester

## Bug Report ### What Was Tested `src/cleveragents/application/services/resource_handler_service.py` `_DefaultHandler` class (lines 287-423) was analyzed for runtime behavior when a resource type has no handler or handler resolution fails. ### Expected Behavior (from spec) Resources should be accessible (read/write/list) through their handlers. When a resource type has no explicit handler, a reasonable default behavior should be provided — at minimum, the `resolve()` method should work for sandbox creation, and CRUD operations should either work or provide a meaningful error message. ### Actual Behavior (from code analysis) `_DefaultHandler` raises `NotImplementedError` for ALL CRUD and lifecycle operations: ```python def read(self, *, resource: Resource, path: str = "") -> Content: raise NotImplementedError("Default handler does not support read()") def write(self, *, resource: Resource, path: str, data: bytes) -> WriteResult: raise NotImplementedError("Default handler does not support write()") def delete(self, *, resource: Resource, path: str = "") -> DeleteResult: raise NotImplementedError("Default handler does not support delete()") def list_children(self, *, resource: Resource) -> list[str]: raise NotImplementedError("Default handler does not support list_children()") def diff(self, *, resource: Resource, other_location: str) -> DiffResult: raise NotImplementedError("Default handler does not support diff()") def discover_children(self, *, resource: Resource) -> list[Resource]: raise NotImplementedError("Default handler does not support discover_children()") def create_sandbox(self, ...) -> SandboxResult: raise NotImplementedError("Default handler does not support create_sandbox()") def create_checkpoint(self, ...) -> CheckpointResult: raise NotImplementedError("Default handler does not support create_checkpoint()") def rollback_to(self, ...) -> RollbackResult: raise NotImplementedError("Default handler does not support rollback_to()") def project_access(self, ...) -> AccessResult: raise NotImplementedError("Default handler does not support project_access()") ``` The `_DefaultHandler` is used when: 1. A resource type has `handler=None` (e.g., all virtual types: `file`, `directory`, `commit`, `branch`, `tag`, `tree`) 2. Handler resolution fails (e.g., handler module not found) This means **all virtual resource types** (which have `handler=None`) will raise `NotImplementedError` for any CRUD operation attempted through `ResourceHandlerService`. ### Impact - All virtual resource types (`file`, `directory`, `commit`, `branch`, `tag`, `tree`, `remote`, `submodule`, `symlink`) will fail with `NotImplementedError` on any CRUD operation - Handler resolution failures silently fall back to `_DefaultHandler` which then raises `NotImplementedError` — the original error is lost - `project_access()` raises `NotImplementedError` — access control checks for resources will fail ### Code Locations - `src/cleveragents/application/services/resource_handler_service.py` lines 287-423 - Virtual types with `handler=None`: `src/cleveragents/application/services/_resource_registry_virtual.py` ### Steps to Reproduce 1. Register a virtual resource (e.g., type `file`) 2. Attempt `ResourceHandlerService.resolve_resource(resource, plan_id, slot_name)` — succeeds (uses sandbox) 3. Attempt `handler.read(resource=resource)` — raises `NotImplementedError` --- **Automated by CleverAgents Bot** Supervisor: UAT Testing | Agent: ca-uat-tester

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UAT: ResourceHandlerService._DefaultHandler raises NotImplementedError for all CRUD operations — resources without explicit handlers fail at runtime #3709