Rule Catalog

Get confused what ast-grep is? This is a list of rewriting rule to inspire you! Explore the power of ast-grep with these rewriting rules that can transform your code in seconds.

Feel free to join our Discord channel and ask @ast-grep-bot to explain the rules for you line by line!

📚 Example Language

CC++GoHTMLJavaKotlinPythonRubyRustTSXTypeScriptYAML

📏 Used Rule

atomic

patternkindregex

relational

insidehasfollowsprecedes

composite

allanynotmatches

Example Type

PatternYAML

💡 More Features

Features

rewriterstransformconstraintsutils

Rule List (36) Sort by: NameLangComplexity

• Avoid `&&` short circuit in JSX

  📏kindhasnot
  🛠️ Fix 📚 TSX

  Try in Playground →
• Avoid Duplicated Exports

  📏allpatterninsidehas
  📚 Rust

  Try in Playground →
• Avoid nested links

  📏patternhas
  📚 TSX

  Try in Playground →
• Avoid Unnecessary React Hook

  📏anypattern+1

  💡utilsconstraints
  📚 TSX

  Try in Playground →
• Beware of char offset when iterate over a string

  Simple Pattern Example
  🛠️ Fix 📚 Rust

  Try in Playground →
• Ensure Clean Architecture

  📏pattern

  💡constraints
  📚 Kotlin

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• Extract i18n Keys

  📏kindpatternnot
  🛠️ Fix 📚 HTML

  Try in Playground →
• Find function declarations with names of certain pattern

  📏kindhas
  📚 Go

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• Find Import File without Extension

  📏regexkindanyinside
  📚 TypeScript

  Try in Playground →
• Find Import Usage

  📏kindpatterninside
  📚 TypeScript

  Try in Playground →
• Find key/value and Show Message

  📏anypattern
  📚 YAML

  Try in Playground →
• Fix Format String Vulnerability

  📏pattern

  💡constraints
  🛠️ Fix 📚 C++

  Try in Playground →
• Get number of digits in a `usize`

  Simple Pattern Example
  🛠️ Fix 📚 Rust

  Try in Playground →
• Match Function Call in C

  📏pattern
  📚 C

  Try in Playground →
• Match Function Call in Golang

  📏pattern
  📚 Go

  Try in Playground →
• Migrate action_filter in Ruby on Rails

  📏anypattern+1

  💡transform
  🛠️ Fix 📚 Ruby

  Try in Playground →
• Migrate OpenAI SDK

  📏pattern
  🛠️ Fix 📚 Python

  Try in Playground →
• Migrate XState to v5 from v4

  📏regexpattern+4

  💡utilstransform
  🛠️ Fix 📚 TypeScript

  Try in Playground →
• No `await` in `Promise.all` array

  📏patterninside
  🛠️ Fix 📚 TypeScript

  Try in Playground →
• No `console` except in `catch` block

  📏anypattern+1

  💡constraints
  🛠️ Fix 📚 TypeScript

  Try in Playground →
• No Unused Vars in Java

  📏kindallhasnot
  📚 Java

  Try in Playground →
• Prefer Generator Expressions

  📏patternkind

  💡transform
  🛠️ Fix 📚 Python

  Try in Playground →
• Prefer Symbol over Proc

  📏pattern

  💡constraints
  🛠️ Fix 📚 Ruby

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• Refactor pytest fixtures

  📏kindfollows+1

  💡utils
  📚 Python

  Try in Playground →
• Remove `async` function

  📏pattern

  💡rewriterstransform
  🛠️ Fix 📚 Python

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• Rename SVG Attribute

  📏patternregex+2

  💡transform
  🛠️ Fix 📚 TSX

  Try in Playground →
• Reverse React Compiler™

  📏anypattern
  🛠️ Fix 📚 TSX

  Try in Playground →
• Rewrite `indoc!` macro

  Simple Pattern Example
  🛠️ Fix 📚 Rust

  Try in Playground →
• Rewrite `Optional[Type]` to `Type | None`

  📏pattern
  🛠️ Fix 📚 Python

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• Rewrite Check to Yoda Condition

  📏patterninside

  💡constraints
  🛠️ Fix 📚 C

  Try in Playground →
• Rewrite Method to Function Call

  📏pattern

  💡transform
  🛠️ Fix 📚 C

  Try in Playground →
• Rewrite MobX Component Style

  📏pattern
  🛠️ Fix 📚 TSX

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• Switch Chai from `should` style to `expect`

  📏anypattern
  🛠️ Fix 📚 TypeScript

  Try in Playground →
• Unnecessary `useState` Type

  Simple Pattern Example
  🛠️ Fix 📚 TSX

  Try in Playground →
• Upgrade Ant Design Vue

  📏kindregex+2

  💡utilsconstraints
  🛠️ Fix 📚 HTML

  Try in Playground →
• Use Walrus Operator in `if` statement

  📏patternfollows
  🛠️ Fix 📚 Python

  Try in Playground →