De Morgan
An ESLint plugin that enforces logical consistency by transforming negated boolean expressions using De Morgan's laws.
What is De Morgan?
ESLint Plugin De Morgan is an ESLint plugin that automatically transforms negated boolean expressions using De Morgan's laws. It rewrites expressions like `!(A && B)` into `!A || !B` and `!(A || B)` into `!A && !B` to improve logical clarity and consistency in code.
JavaScript and TypeScript developers who want to enforce consistent boolean logic transformations and improve code readability in their projects.
It provides automated, mathematically grounded transformations that reduce logical errors and enhance code clarity, integrating seamlessly into existing ESLint workflows with auto-fix capabilities.
Overview
🧵 ESLint plugin for transforming negated boolean expressions via De Morgan’s laws
Use Cases
Best For
- Enforcing consistent boolean expression styles across a codebase
- Automatically simplifying complex negated logical conditions
- Reducing subtle logical bugs in conditional statements
- Improving code readability in projects with heavy boolean logic
- Integrating mathematical Boolean algebra principles into code reviews
- Teaching or reinforcing De Morgan's laws in programming contexts
Not Ideal For
- Projects where boolean expressions are intentionally written with negations for specific readability or domain logic
- Teams using minimal ESLint configurations or preferring linter-free development environments
- Codebases that require comprehensive logical optimizations beyond De Morgan's laws, such as boolean simplification or other algebraic transformations
Pros & Cons
Pros
Provides auto-fix capabilities via ESLint's --fix option, automatically rewriting negated expressions like !(a && b) into !a || !b without manual intervention.
Grounded in De Morgan's laws from Boolean algebra, ensuring transformations are logically correct and consistent, as emphasized in the README's philosophy.
Offers ready-made configs for both flat and legacy ESLint configurations, simplifying setup with minimal configuration effort.
Includes detailed examples in the README, such as transforming complex expressions like !(a || !b || c >= 10), making it easy to understand the transformations.
Cons
Only includes two rules (no-negated-conjunction and no-negated-disjunction), missing broader boolean logic optimizations or edge cases like nested negations with mixed operators.
May enforce transformations that override team preferences for negation placement, potentially reducing readability in contexts where negated expressions are clearer.
Requires ESLint to be installed and configured, adding overhead for projects not already using ESLint or opting for alternative linting tools.
Frequently Asked Questions
Related Projects
UnicornMore than 300 powerful ESLint rules
SonarJSSonarSource Static Analyzer for JavaScript and TypeScript
dependAn ESLint plugin for suggesting optimisations in choice of dependency, native equivalents, etc.
GitHubAn opinionated collection of ESLint rules used by GitHub.
Found a gem we're missing?
Open-Awesome is built by the community, for the community. Submit a project, suggest an awesome list, or help improve the catalog on GitHub.