zmod
Guide
API
Guide
API

Getting Started

Installation

npm install zmod
# or
pnpm add zmod

Basic Usage

Simple API

No AST traversal needed for common transformations.

import { transform } from "zmod";

transform(source, {
  renames: { foo: "bar" },
  imports: {
    replaceSource: { "react-dom/test-utils": "react" },
    removeSpecifier: ["act"],
  },
});

jscodeshift-compatible API

Full AST traversal for complex transformations. Drop-in replacement for jscodeshift.

import type { Transform } from "zmod";

const transform: Transform = ({ source }, { z }) => {
  return z(source)
    .find(z.CallExpression, {
      callee: { name: "React.forwardRef" },
    })
    .replaceWith((path) => path.node.arguments[0])
    .toSource();
};

export default transform;

Running a Transform

import { run } from "zmod";
import transform from "./my-transform";

await run(transform, { include: "src/**/*.tsx" });

Custom Parsers

By default zmod uses oxc to parse source files. You can swap in any ESTree-compatible parser using z.withParser().

Inline override

import { z } from "zmod";
import { parse } from "@babel/parser";

const j = z.withParser({
  parse(source) {
    return parse(source, {
      plugins: [["decorators", { version: "legacy" }], "typescript"],
      sourceType: "module",
    }).program;
  },
});

export default function transform({ source }) {
  return j(source).find(j.Identifier, { name: "injectable" }).replaceWith("singleton").toSource();
}

Per-transform parser export

Export a parser from your transform file and run() will pick it up automatically:

import type { Parser, Transform } from "zmod";
import { parse } from "@babel/parser";

export const parser: Parser = {
  parse(source) {
    return parse(source, { plugins: ["typescript"], sourceType: "module" }).program;
  },
};

const transform: Transform = ({ source }, { z }) => {
  // z here already uses the exported parser
  return z(source).find(z.Identifier, { name: "foo" }).replaceWith("bar").toSource();
};

export default transform;

This is compatible with jscodeshift's module.exports.parser pattern.

Migration from jscodeshift

Already have jscodeshift codemods? Migrate automatically:

npx @zmod/migrate "codemods/**/*.ts"

See the Migration Guide for details.

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