test.js

const assert = require('assert')
const transform = require("@babel/core").transform
const plugin = require('./')

transform(`
<div className={[a,b && fo]} />;
classNames(a, b && foo);
<div className="hhi" />;
<div className={hhi} />;
<div className={[a,b && fo].join('')} />;
`.trim(), { plugins: ["@babel/plugin-syntax-jsx", plugin] }, (err, result) => {
  if (err) {
    throw err
  }
  assert.equal(
    result.code,
    `
import _classNames from "classnames";
<div className={_classNames(a, b && fo)} />;
classNames(a, b && foo);
<div className="hhi" />;
<div className={hhi} />;
<div className={[a, b && fo].join('')} />;
    `.trim()
  )
})


transform(`
<div className={[a,b && fo]} />;
`.trim(), { plugins: ["@babel/plugin-syntax-jsx", [plugin, { importName: 'cx' }]] }, (err, result) => {
  if (err) {
    throw err
  }
  assert.equal(
    result.code,
    `
import { cx as _classNames } from "classnames";
<div className={_classNames(a, b && fo)} />;
    `.trim()
  )
})


transform(`
<div className={[a,b && fo]} />;
`.trim(), { plugins: ["@babel/plugin-syntax-jsx", [plugin, { packageName: 'foo' }]] }, (err, result) => {
  if (err) {
    throw err
  }
  assert.equal(
    result.code,
    `
import _classNames from "foo";
<div className={_classNames(a, b && fo)} />;
    `.trim()
  )
})


transform(`
<div className={{ foo }} />;
`.trim(), { plugins: ["@babel/plugin-syntax-jsx", [plugin, { transformObjects: true }]] }, (err, result) => {
  if (err) {
    throw err
  }
  assert.equal(
    result.code,
    `
import _classNames from "classnames";
<div className={_classNames({
  foo
})} />;
    `.trim()
  )
})


transform(`
<div className={{ foo }} />;
`.trim(), { plugins: ["@babel/plugin-syntax-jsx", [plugin, { transformObjects: false }]] }, (err, result) => {
  if (err) {
    throw err
  }
  assert.equal(
    result.code,
    `
<div className={{
  foo
}} />;
    `.trim()
  )
})


transform(`
<div className={[a,b && fo]}><div className={[styles.foo]} /></div>;
`.trim(), { presets: ["@babel/env"],  plugins: ["@babel/plugin-syntax-jsx", plugin] }, (err, result) => {
  if (err) {
    throw err
  }

  assert.equal(
    result.code,
    `
"use strict";

var _classnames = _interopRequireDefault(require("classnames"));

function _interopRequireDefault(obj) { return obj && obj.__esModule ? obj : { default: obj }; }

<div className={(0, _classnames.default)(a, b && fo)}><div className={(0, _classnames.default)(styles.foo)} /></div>;
`.trim()
  )
})