Diagnostics

🙺 Diagnostic Checks (Updated for Azure Functions Python Programming Model v2)

This document lists diagnostic checks for Azure Functions Doctor, based on Azure Functions Python Reference and Best Practices.

#	Diagnostic Check	Description	Feasibility	Status
1	Python version ≥ 3.9	Check if the runtime meets minimum requirements	✅ Easy	✅ Implemented
2	Virtual environment (.venv) active	Ensure Python environment is isolated via virtualenv	✅ Easy	✅ Implemented
3	Azure Functions Core Tools installed	Validate that func CLI is installed and accessible	✅ Easy	✅ Implemented
4	host.json exists	Required runtime configuration file must be present	✅ Easy	✅ Implemented
5	requirements.txt exists	Check for dependency management file	✅ Easy	✅ Implemented
6	azure-functions package installed	Ensure required Azure Functions SDK is installed	✅ Easy	✅ Implemented
7	azure-functions-python-library installed	Required for Programming Model v2 decorator syntax	✅ Easy	✅ Implemented
8	local.settings.json exists (optional)	Useful for storing app settings locally	✅ Easy	🔧 Planned
9	Detect use of decorators	Confirm use of v2-style decorators like @function_name	✅ Easy	✅ Implemented
10	Function mode detection (v1 vs v2)	Detect whether app uses function.json or decorators	✅ Medium	🔧 Planned
11	Directory structure validation	Warn if folder structure is non-standard or missing expected files	✅ Easy	✅ Implemented
12	Durable Functions config in host.json	Check for presence of durableTask section	✅ Medium	🔧 Planned
13	HTTP trigger validation	Ensure authLevel, methods, route in binding are valid	✅ Medium	🔧 Planned
14	Timer trigger CRON validation	Validate correct CRON format	✅ Medium	🔧 Planned
15	App Insights configuration	Validate presence of instrumentation key or connection string	✅ Medium	🔧 Planned
16	EntryPoint in function.json (v1 only)	Check if entryPoint matches a real function (v1 only)	✅ Easy	❌ Not needed
17	Function name and folder match (v1 only)	Ensure folder/function naming aligns (v1 only)	✅ Easy	❌ Not needed
18	ASGI/WSGI compatibility	Check if app exposes ASGI/WSGI callable	✅ Medium	🔧 Planned
19	Detect unused or invalid files	Warn about .pyc, __pycache__, or legacy files	✅ Low	🔝 Possible
20	Detect long-running blocking patterns	Detect sleep(), infinite loops, or sync IO blocking	❌ Hard	❌ Not feasible
21	Excessive logging	Detect overuse of print() or logging.debug()	❌ Runtime	❌ Not feasible
22	Monolithic layout warning	Detect if everything is in one large file	❌ Context	❌ Not feasible

Legend: ✅ Easy = statically checkable
✅ Medium = requires additional parsing/context
❌ = not feasible by static analysis
🔧 Planned = scheduled for future implementation
🧭 Possible = technically feasible but lower priority

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✅ Key Changes

• Removed main.py check (was v1 specific)
• Added decorator detection (v2 model confirmation)
• Excluded v1-only checks like entryPoint, function.json folder matching
• Included v2-only checks like azure-functions-python-library
• Clarified feasibility and implementation status across all checks