maxFunctionDefs

maxFunctionDefs is a configurable limit used in software quality tooling to cap the number of function definitions allowed within a single source file or module. The goal is to enforce maintainability and readability by preventing files from becoming overly large and complex.

Semantics vary by tool. Some implementations count only top-level function definitions in a file, others include methods within classes or closures; some count named functions only, others count anonymous functions as well. Because of this variability, the exact meaning of a count should be documented for the specific tool being used.

Usage and behavior typically involve reporting when the function count exceeds the configured threshold. The tool may emit a warning or error and, in some setups, fail a build or lint job. Developers can then refactor by splitting the file into smaller modules, extracting functions, or reorganizing code to reduce the number of definitions in a single unit.

Configuration and scope are commonly exposed in project settings. The parameter is often available in configuration files or via command line options, with formats such as YAML, JSON, or language-specific configs. It can be set per project, per directory, or per language, and many implementations allow combining maxFunctionDefs with related constraints like maximum lines per function or overall file size.

Impact and best practices emphasize balance. While a reasonable maxFunctionDefs can promote modular design and easier maintenance, overly strict limits may hinder legitimate patterns. It is best used alongside other quality metrics and with clear criteria for when a refactor is warranted.