esbuild 0.12.17

v0.12.17

on Node.js NPM

Fix a bug with private fields and logical assignment operators (#1418)

This release fixes a bug where code using private fields in combination with logical assignment operators was transformed incorrectly if the target environment supported logical assignment operators but not private fields. Since logical assignment operators are assignment operators, the entire operator must be transformed even if the operator is supported. This should now work correctly:

// Original code
class Foo {
  #x
  foo() {
    this.#x &&= 2
    this.#x ||= 2
    this.#x ??= 2
  }
}

// Old output
var _x;
class Foo {
  constructor() {
    __privateAdd(this, _x, void 0);
  }
  foo() {
    this._x &&= 2;
    this._x ||= 2;
    this._x ??= 2;
  }
}
_x = new WeakMap();

// New output
var _x, _a;
class Foo {
  constructor() {
    __privateAdd(this, _x, void 0);
  }
  foo() {
    __privateGet(this, _x) && __privateSet(this, _x, 2);
    __privateGet(this, _x) || __privateSet(this, _x, 2);
    __privateGet(this, _x) ?? __privateSet(this, _x, 2);
  }
}
_x = new WeakMap();

Fix a hoisting bug in the bundler (#1455)

This release fixes a bug where variables declared using var inside of top-level for loop initializers were not hoisted inside lazily-initialized ES modules (such as those that are generated when bundling code that loads an ES module using require). This meant that hoisted function declarations incorrectly didn't have access to these loop variables:

// entry.js
console.log(require('./esm-file').test())

// esm-file.js
for (var i = 0; i < 10; i++) ;
export function test() { return i }

Old output (incorrect):

// esm-file.js
var esm_file_exports = {};
__export(esm_file_exports, {
  test: () => test
});
function test() {
  return i;
}
var init_esm_file = __esm({
  "esm-file.js"() {
    for (var i = 0; i < 10; i++)
      ;
  }
});

// entry.js
console.log((init_esm_file(), esm_file_exports).test());

New output (correct):

// esm-file.js
var esm_file_exports = {};
__export(esm_file_exports, {
  test: () => test
});
function test() {
  return i;
}
var i;
var init_esm_file = __esm({
  "esm-file.js"() {
    for (i = 0; i < 10; i++)
      ;
  }
});

// entry.js
console.log((init_esm_file(), esm_file_exports).test());

Fix a code generation bug for private methods (#1424)

This release fixes a bug where when private methods are transformed and the target environment is one that supports private methods (such as esnext), the member function name was uninitialized and took on the zero value by default. This resulted in the member function name becoming __create instead of the correct name since that's the name of the symbol at index 0. Now esbuild always generates a private method symbol even when private methods are supported, so this is no longer an issue:

// Original code
class Foo {
  #a() { return 'a' }
  #b() { return 'b' }
  static c
}

// Old output
var _a, __create, _b, __create;
var Foo = class {
  constructor() {
    __privateAdd(this, _a);
    __privateAdd(this, _b);
  }
};
_a = new WeakSet();
__create = function() {
  return "a";
};
_b = new WeakSet();
__create = function() {
  return "b";
};
__publicField(Foo, "c");

// New output
var _a, a_fn, _b, b_fn;
var Foo = class {
  constructor() {
    __privateAdd(this, _a);
    __privateAdd(this, _b);
  }
};
_a = new WeakSet();
a_fn = function() {
  return "a";
};
_b = new WeakSet();
b_fn = function() {
  return "b";
};
__publicField(Foo, "c");

The CLI now stops watch and serve mode when stdin is closed (#1449)

To facilitate esbuild being called from the Erlang VM, esbuild's command-line interface will now exit when in --watch or --serve mode if stdin is closed. This change is necessary because the Erlang VM doesn't have an API for terminating a child process, so it instead closes stdin to indicate that the process is no longer needed.

Note that this only happens when stdin is not a TTY (i.e. only when the CLI is being used non-interactively) to avoid disrupting the use case of manually moving esbuild to a background job using a Unix terminal.

This change was contributed by @josevalim.