BUG-HUNT: [error-handling] Unhandled exceptions in robot.json_helper.load_json_file #2814

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opened 2026-04-04 20:37:47 +00:00 by freemo · 0 comments

freemo commented

2026-04-04 20:37:47 +00:00

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Metadata

Branch: fix/error-handling-json-helper-load-json-file
Commit Message: fix(error-handling): handle FileNotFoundError and JSONDecodeError in robot.json_helper.load_json_file
Milestone: v3.7.0
Parent Epic: #362

Description

The load_json_file method in robot/json_helper.py does not handle FileNotFoundError if the file path does not exist, or json.JSONDecodeError if the file contains invalid JSON. This can cause a test case to crash unexpectedly with an unhandled exception propagating to the caller.

Location

File: robot/json_helper.py
Function/Class: JsonHelper.load_json_file
Lines: 15–18

Evidence

@staticmethod
def load_json_file(file_path):
    """Load JSON from a file and return as a dictionary."""
    with open(file_path) as f:
        return json.load(f)

Expected Behavior

The method should catch FileNotFoundError and json.JSONDecodeError and return a sensible default value (e.g., None) to prevent the test case from crashing unexpectedly.

Actual Behavior

The method raises unhandled FileNotFoundError or json.JSONDecodeError when given a non-existent file path or a file with invalid JSON content.

Suggested Fix

Wrap the file operations in a try...except block:

import json
from typing import Optional

@staticmethod
def load_json_file(file_path: str) -> Optional[dict]:
    """Load JSON from a file and return as a dictionary."""
    try:
        with open(file_path) as f:
            return json.load(f)
    except (FileNotFoundError, json.JSONDecodeError):
        return None

Severity Assessment

Impact: A test case will crash if it provides a non-existent file path or a file with invalid JSON.
Likelihood: Medium — test data files might be missing or malformed.
Priority: Medium

Subtasks

Add try...except block to JsonHelper.load_json_file catching FileNotFoundError and json.JSONDecodeError
Add explicit type annotations to load_json_file signature (return type Optional[dict], parameter type str)
Write Behave unit tests covering: file not found, invalid JSON, and valid JSON scenarios
Write Robot Framework integration test verifying the fix end-to-end
Verify nox -e typecheck passes with no type errors
Verify nox -e lint passes with no lint errors

Definition of Done

JsonHelper.load_json_file catches FileNotFoundError and returns None instead of raising
JsonHelper.load_json_file catches json.JSONDecodeError and returns None instead of raising
All type annotations are explicit and complete (no implicit Any)
Behave unit tests added for all three scenarios (missing file, invalid JSON, valid JSON)
Robot Framework integration test updated or added to cover the fix
All nox stages pass
Coverage >= 97%

Automated by CleverAgents Bot
Supervisor: Unknown | Agent: ca-new-issue-creator

## Metadata - **Branch**: `fix/error-handling-json-helper-load-json-file` - **Commit Message**: `fix(error-handling): handle FileNotFoundError and JSONDecodeError in robot.json_helper.load_json_file` - **Milestone**: v3.7.0 - **Parent Epic**: #362 ## Description The `load_json_file` method in `robot/json_helper.py` does not handle `FileNotFoundError` if the file path does not exist, or `json.JSONDecodeError` if the file contains invalid JSON. This can cause a test case to crash unexpectedly with an unhandled exception propagating to the caller. ### Location - **File**: `robot/json_helper.py` - **Function/Class**: `JsonHelper.load_json_file` - **Lines**: 15–18 ### Evidence ```python @staticmethod def load_json_file(file_path): """Load JSON from a file and return as a dictionary.""" with open(file_path) as f: return json.load(f) ``` ### Expected Behavior The method should catch `FileNotFoundError` and `json.JSONDecodeError` and return a sensible default value (e.g., `None`) to prevent the test case from crashing unexpectedly. ### Actual Behavior The method raises unhandled `FileNotFoundError` or `json.JSONDecodeError` when given a non-existent file path or a file with invalid JSON content. ### Suggested Fix Wrap the file operations in a `try...except` block: ```python import json from typing import Optional @staticmethod def load_json_file(file_path: str) -> Optional[dict]: """Load JSON from a file and return as a dictionary.""" try: with open(file_path) as f: return json.load(f) except (FileNotFoundError, json.JSONDecodeError): return None ``` ### Severity Assessment - **Impact**: A test case will crash if it provides a non-existent file path or a file with invalid JSON. - **Likelihood**: Medium — test data files might be missing or malformed. - **Priority**: Medium ## Subtasks - [ ] Add `try...except` block to `JsonHelper.load_json_file` catching `FileNotFoundError` and `json.JSONDecodeError` - [ ] Add explicit type annotations to `load_json_file` signature (return type `Optional[dict]`, parameter type `str`) - [ ] Write Behave unit tests covering: file not found, invalid JSON, and valid JSON scenarios - [ ] Write Robot Framework integration test verifying the fix end-to-end - [ ] Verify `nox -e typecheck` passes with no type errors - [ ] Verify `nox -e lint` passes with no lint errors ## Definition of Done - [ ] `JsonHelper.load_json_file` catches `FileNotFoundError` and returns `None` instead of raising - [ ] `JsonHelper.load_json_file` catches `json.JSONDecodeError` and returns `None` instead of raising - [ ] All type annotations are explicit and complete (no implicit `Any`) - [ ] Behave unit tests added for all three scenarios (missing file, invalid JSON, valid JSON) - [ ] Robot Framework integration test updated or added to cover the fix - [ ] All nox stages pass - [ ] Coverage >= 97% --- **Automated by CleverAgents Bot** Supervisor: Unknown | Agent: ca-new-issue-creator

freemo added this to the v3.7.0 milestone

2026-04-04 20:37:53 +00:00

freemo added a new dependency

2026-04-04 20:38:08 +00:00

#362 Epic: Security & Safety Hardening

freemo added the

MoSCoW

Could have

label

2026-04-04 20:41:07 +00:00

freemo referenced this issue

2026-04-04 20:41:23 +00:00