editc

Edit code by powerful AST Selectors without old_text.

Usage

npm install

# Option 1: Run directly with tsx (no build required)
npx tsx src/editc.ts index.ts --selector "Class::MyService Method::hello" --replace "hello() { console.log('done'); }"

# Option 2: Build and run
npm run build
node dist/editc.js index.ts --selector "Class::MyService Method::hello Block" --replace "return 42;"

Selector Syntax

The AST Selector syntax works similarly to CSS Selectors, matching elements down the TypeScript Abstract Syntax Tree.

Basic Format

Each part of a selector is space-separated, representing a descendant relationship. Format for a single part: [Kind]::[Name][text^="Prefix"]:comment

Component	Description	Example
Kind	The AST SyntaxKind. We support all native kinds (e.g., VariableDeclaration, Identifier, ReturnStatement), and provide friendly aliases like Class, Function, Method, ForBlock, IfBlock, Block.	Function or FunctionDeclaration
::Name	Matches the explicit .getName() or the identifier text of the node.	Class::MyService
[text^="..."]	A property selector that matches if the node's full text starts with the specified prefix.	ForBlock[text^="for (let i = 0"]
:comment	A pseudo-class that targets the leading JSDoc or line comment attached to the node, instead of the node itself.	Method::hello:comment

CLI Options

• --selector <query> : The AST selector path (required).
• --replace <code> : Replace the matched node with the given code.
• --replace-file <filepath> : Load replacement code from a file.
• --delete : Delete the targeted node entirely.
• --before <code> : Insert text right before the targeted node.
• --after <code> : Insert text right after the targeted node.
• --all : By default, editc edits the first matching node. Pass --all to edit all matching nodes globally in the file scope.

Examples

Assume the source file index.ts:

class MyService {
  hello() {
    console.log("1");
  }
}

function fib(n: number) {
  let fib = [0, 1];
  for (let i = 2; i < n; i++) {
    fib[i] = fib[i - 1] + fib[i - 2];
  }
  return fib;
}

Replace an entire method

npx tsx src/editc.ts index.ts --selector "Class::MyService Method::hello" --replace "hello() { console.log('hi'); }"

Replace only the method body (auto-wraps in braces)

npx tsx src/editc.ts index.ts --selector "Class::MyService Method::hello Block" --replace "console.log('new body');"

Delete a specific block statement using text prefix

npx tsx src/editc.ts index.ts --selector "Function::fib Block VariableStatement[text^='let fib =']" --delete

Replace Comments

Use :comment to edit JSDocs safely. You don't need to wrap your replacement in /** */, the tool does it for you.

npx tsx src/editc.ts index.ts --selector "Class::MyService Method::hello:comment" --replace "Says hello."

Global Rename / Replace using --all

Find all variables/identifiers named fib and rename them.

npx tsx src/editc.ts index.ts --selector "Function::fib Block Identifier::fib" --replace "fib_arr" --all