babel/packages/babel-plugin-transform-regenerator/test/regenerator-fixtures/class.js

/**
 * Copyright (c) 2014-present, Facebook, Inc.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

var assert = require("assert");
var shared = require("./shared.js");
var check = shared.check;

assert(
  function*() {}.toString().indexOf("regenerator") !== -1,
  "regenerator-transform should be enabled"
);

describe("class methods", function () {
  it("should work if the generator is a class method", function () {
    class Foo {
      *gen(x) {
        yield x;
      }
    }

    check(new Foo().gen("boom"), ["boom"]);
  });

  it("should work if the generator is a computed class method", function () {
    var fnName = "gen";
    class Foo {
      *[fnName](x) {
        yield x;
      }
    }

    check(new Foo().gen("boom"), ["boom"]);
  });

  it("should work with this", function () {
    class A {
      *gen() { yield this }
    }

    const a = new A;
    check(a.gen(), [a]);
  })

  it("should work with super", function () {
    class A {
      *gen() { yield 1 }
    }

    class B extends A {
      *gen() { yield super.gen; }
    }

    check(new B().gen(), [A.prototype.gen]);
  });

  it("should work with arguments", function () {
    class A {
      *gen() { yield arguments }
    }

    const args = new A().gen(1, 2, 3).next().value;
    assert.strictEqual(args.length, 3);
    assert.strictEqual(args[0], 1);
    assert.strictEqual(args[1], 2);
    assert.strictEqual(args[2], 3)
  });

  it("should allow yield as super expression", function () {
    function* gen() {
      return class extends (yield) {}
    }

    class B {}

    const it = gen();
    it.next();
    const res = it.next(B).value;

    assert.ok(new res instanceof B);
  });

  it("should allow yield as super expression with argument", function () {
    function* gen() {
      return class extends (yield 123) {}
    }

    class B {}

    const it = gen();
    assert.deepEqual(it.next(), { value: 123, done: false });
    const res = it.next(B).value;

    assert.ok(new res instanceof B);
  });

  it("should allow yield as computed key", function () {
    if (class {}.toString().indexOf("class") !== 0) {
      return;
      // The class transform is broken:
      // https://github.com/babel/babel/issues/8300
    }

    function* gen() {
      return class {
        [yield]() { return 1 }
        [yield]() { return 2 }
      }
    }

    const it = gen();
    it.next();
    it.next("one");
    const res = it.next("two").value;

    assert.strictEqual(new res().one(), 1);
    assert.strictEqual(new res().two(), 2);
  });
});