Built-in Rule Inventory

This page is the single source of truth for all built-in rules shipped with Azure Functions Doctor. Rules are defined in src/azure_functions_doctor/assets/rules/v2.json.

Rule Table

Rule ID	Label	Category	Section	Type	Required	Profile
check_programming_model_v2	Programming model v2	project_structure	programming_model	source_code_contains	No	full
check_python_version	Python version	environment	python_env	compare_version	Yes	minimal, full
check_venv	Virtual environment	environment	python_env	env_var_exists	No	full
check_python_executable	Python executable	environment	python_env	path_exists	No	full
check_requirements_txt	requirements.txt	dependencies	python_env	file_exists	Yes	minimal, full
check_azure_functions_library	azure-functions package	dependencies	python_env	package_declared	Yes	minimal, full
check_azure_functions_worker	azure-functions-worker not pinned	dependencies	python_env	package_forbidden	No	full
check_host_json	host.json	structure	project_structure	file_exists	Yes	minimal, full
check_host_json_version	host.json version	structure	project_structure	host_json_version	Yes	minimal, full
check_local_settings	local.settings.json	structure	project_structure	file_exists	No	full
check_func_cli	Azure Functions Core Tools (func)	tooling	tooling	executable_exists	No	full
check_func_core_tools_version	Azure Functions Core Tools version	tooling	tooling	compare_version	No	full
check_durabletask_config	Durable Functions configuration	configuration	durable	conditional_exists	No	full
check_app_insights	Application Insights configuration	telemetry	monitoring	any_of_exists	No	full
check_extension_bundle	extensionBundle	configuration	extensions	host_json_property	No	full
check_asgi_wsgi_exposure	ASGI/WSGI compatibility	framework	asgi_wsgi	callable_detection	No	full
check_unused_files	Detect unused or invalid files	project_health	cleanup	file_glob_check	No	full
check_funcignore	.funcignore	project_health	cleanup	file_exists	No	full
check_local_settings_git_tracked	local.settings.json not git-tracked	project_health	security	local_settings_security	No	full
check_extension_bundle_v4	extensionBundle v4 recommended	configuration	extensions	host_json_extension_bundle_version	No	full

Rule Types

Type	Description
compare_version	Compares a runtime version against a minimum threshold.
file_exists	Checks whether a file exists at the project root.
env_var_exists	Checks whether an environment variable is set.
path_exists	Checks whether a filesystem path (e.g. sys.executable) exists.
package_installed	Checks whether a Python package is importable in the current environment.
package_declared	Checks whether a package name appears in a dependency file.
package_forbidden	Checks that a platform-managed package is NOT declared in a dependency file.
source_code_contains	Scans Python source files for a keyword or AST pattern.
conditional_exists	Checks for a JSON property only when a related condition is detected.
callable_detection	Detects whether the project exposes an ASGI or WSGI callable.
executable_exists	Checks whether an executable is available on PATH.
any_of_exists	Passes if any one of several targets (env vars, JSON properties) is present.
file_glob_check	Matches file glob patterns to detect unwanted files in the project tree.
host_json_property	Checks for a specific property in host.json via JSONPath.
host_json_version	Checks that host.json declares "version": "2.0".
local_settings_security	Checks that local.settings.json is not tracked by git.
host_json_extension_bundle_version	Checks that extensionBundle in host.json uses the recommended v4 range.

False-positive Risk

The following rule types use heuristic inspection and may produce false positives in unusual project layouts:

• source_code_contains (check_programming_model_v2): Searches for @app. in Python files. Projects that use @app. for non-Azure-Functions decorators may trigger a false positive.
• callable_detection (check_asgi_wsgi_exposure): Inspects source for ASGI/WSGI patterns. Non-standard callable exposure may not be detected.
• file_glob_check (check_unused_files): Matches common unwanted file patterns. Intentionally kept files (e.g. tests/ in monorepos) may trigger warnings.

False positives in stable rules are treated as bugs. See the Semver Policy for details.