Fix handling of JS keyword when causing invalid code gen (#4329)

CHANGELOG.md

@@ -13,6 +13,18 @@
 * Optional parameters are now typed as `T | undefined | null` to reflect the actual JS behavior.
   [#4188](https://github.com/rustwasm/wasm-bindgen/pull/4188)
 
+### Fixed
+
+- Fixed using [JavaScript keyword](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Lexical_grammar#keywords) as identifiers not being handled correctly.
+  [#4329](https://github.com/rustwasm/wasm-bindgen/pull/4329)
+
+  - Using JS keywords as `struct` and `enum` names will now error at compile time, instead of causing invalid JS code gen.
+  - Using JS keywords that are not valid to call or access properties on will now error at compile time, instead of causing invalid JS code gen if used as:
+    1. The first part of a `js_namespace` on imports.
+    2. The name of an imported type or constant if the type or constant does not have a `js_namespace` or `module` attribute.
+    3. The name of an imported function if the function is not a method and does not have a `js_namespace` or `module` attribute.
+  - Using JS keywords on imports in places other than the above will no longer cause the keywords to be escaped as `_{keyword}`.
+
 --------------------------------------------------------------------------------
 
 ## [0.2.99](https://github.com/rustwasm/wasm-bindgen/compare/0.2.98...0.2.99)

crates/cli/tests/reference/import.js

@@ -1,3 +1,5 @@
+import { default as default1 } from 'tests/wasm/import_class.js';
+
 let wasm;
 export function __wbg_set_wasm(val) {
     wasm = val;
@@ -65,6 +67,20 @@ export function __wbg_catchme_f7d87ea824a61e87() { return handleError(function (
     catch_me();
 }, arguments) };
 
+export function __wbg_get_56ba567010fb9959(arg0) {
+    const ret = arg0.get();
+    return ret;
+};
+
+export function __wbg_myfunction_8c7b624429f78550() {
+    b.my_function();
+};
+
+export function __wbg_new_d21827b66c7fd25d(arg0) {
+    const ret = new default1(arg0);
+    return ret;
+};
+
 export function __wbg_nocatch_be850a8dddd9599d() {
     no_catch();
 };
@@ -73,6 +89,11 @@ export function __wbg_reload_84c12f152ad689f0() {
     window.location.reload();
 };
 
+export function __wbg_static_accessor_CONST_9e9d5ae758197645() {
+    const ret = a.CONST;
+    return ret;
+};
+
 export function __wbg_write_c2ce0ce33a6087d5(arg0, arg1) {
     window.document.write(getStringFromWasm0(arg0, arg1));
 };

crates/cli/tests/reference/import.rs

@@ -23,12 +23,36 @@ extern "C" {
     fn add(a: f64, b: f64) -> f64;
 }
 
+#[wasm_bindgen(js_namespace = ["a"])]
+extern "C" {
+    // test that namespaces are overwritten and not inherited/concatenated
+    #[wasm_bindgen(js_namespace = ["b"])]
+    fn my_function();
+    #[wasm_bindgen(thread_local_v2)]
+    static CONST: f64;
+}
+
+#[wasm_bindgen(module = "tests/wasm/import_class.js")]
+extern "C" {
+    #[wasm_bindgen(js_name = default)]
+    type RenamedTypes;
+    #[wasm_bindgen(constructor, js_class = default)]
+    fn new(arg: i32) -> RenamedTypes;
+    #[wasm_bindgen(method, js_class = default)]
+    fn get(this: &RenamedTypes) -> i32;
+}
+
 #[wasm_bindgen]
 pub fn exported() -> Result<(), JsValue> {
     bar_from_foo();
-    let _ = add(1.0, 2.0);
+    let _ = add(CONST.with(Clone::clone), 2.0);
     reload();
     write("");
     no_catch();
+    my_function();
+
+    let f = RenamedTypes::new(1);
+    assert_eq!(f.get(), 2);
+
     catch_me()
 }

crates/cli/tests/reference/keyword.d.ts

@@ -0,0 +1,6 @@
+/* tslint:disable */
+/* eslint-disable */
+export function exported(): void;
+export function _function(): void;
+export function _var(): void;
+export function weird_arguments(_new: number, _var: number, _switch: number, _default: number, _arguments: number): void;

crates/cli/tests/reference/keyword.js

@@ -0,0 +1,91 @@
+let wasm;
+export function __wbg_set_wasm(val) {
+    wasm = val;
+}
+
+
+const lTextDecoder = typeof TextDecoder === 'undefined' ? (0, module.require)('util').TextDecoder : TextDecoder;
+
+let cachedTextDecoder = new lTextDecoder('utf-8', { ignoreBOM: true, fatal: true });
+
+cachedTextDecoder.decode();
+
+let cachedUint8ArrayMemory0 = null;
+
+function getUint8ArrayMemory0() {
+    if (cachedUint8ArrayMemory0 === null || cachedUint8ArrayMemory0.byteLength === 0) {
+        cachedUint8ArrayMemory0 = new Uint8Array(wasm.memory.buffer);
+    }
+    return cachedUint8ArrayMemory0;
+}
+
+function getStringFromWasm0(ptr, len) {
+    ptr = ptr >>> 0;
+    return cachedTextDecoder.decode(getUint8ArrayMemory0().subarray(ptr, ptr + len));
+}
+
+export function exported() {
+    wasm.exported();
+}
+
+export function _function() {
+    wasm._function();
+}
+
+export function _var() {
+    wasm._var();
+}
+
+/**
+ * @param {number} _new
+ * @param {number} _var
+ * @param {number} _switch
+ * @param {number} _default
+ * @param {number} _arguments
+ */
+export function weird_arguments(_new, _var, _switch, _default, _arguments) {
+    wasm.weird_arguments(_new, _var, _switch, _default, _arguments);
+}
+
+export function __wbg_await_e0a0e75be8b6fef6() {
+    await();
+};
+
+export function __wbg_let_8d461e9e0592bd8c(arg0) {
+    arg0.let();
+};
+
+export function __wbg_new_4b026aaf1c1e4438() {
+    const ret = A.new();
+    return ret;
+};
+
+export function __wbg_new_d4bfd9add722b492() {
+    const ret = window.__TAURI__.menu.Menu.new();
+    return ret;
+};
+
+export function __wbg_new_e17dd7c5a1cd57d8() {
+    B.new();
+};
+
+export function __wbg_static_accessor_TRUE_c6b68bf8545d99a3() {
+    const ret = true;
+    return ret;
+};
+
+export function __wbindgen_init_externref_table() {
+    const table = wasm.__wbindgen_export_0;
+    const offset = table.grow(4);
+    table.set(0, undefined);
+    table.set(offset + 0, undefined);
+    table.set(offset + 1, null);
+    table.set(offset + 2, true);
+    table.set(offset + 3, false);
+    ;
+};
+
+export function __wbindgen_throw(arg0, arg1) {
+    throw new Error(getStringFromWasm0(arg0, arg1));
+};
+

crates/cli/tests/reference/keyword.rs

@@ -0,0 +1,57 @@
+use wasm_bindgen::prelude::*;
+
+// Imports with keywords
+
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen]
+    pub type A;
+
+    #[wasm_bindgen(static_method_of = A, js_name = "new")]
+    pub fn static_new() -> A;
+    #[wasm_bindgen(js_namespace = ["B"], js_name = "new")]
+    pub fn namespace_new();
+
+    #[wasm_bindgen(method, js_name = "let")]
+    pub fn keyword_let(ptr: &A);
+
+    // await is not a reserved keyword in JS
+    pub fn r#await();
+
+    // true & false are reserved keywords in JS, but we allow them anyway
+    #[wasm_bindgen(thread_local_v2, js_name = "true")]
+    static TRUE: JsValue;
+}
+
+// https://github.com/rustwasm/wasm-bindgen/issues/4317
+#[wasm_bindgen(js_namespace = ["window", "__TAURI__", "menu"])]
+extern "C" {
+    #[wasm_bindgen]
+    pub type Menu;
+
+    #[wasm_bindgen(static_method_of = Menu)]
+    pub fn new() -> Menu;
+}
+
+// This function ensures the imported stuff isn't optimized out
+#[wasm_bindgen]
+pub fn exported() {
+    let a = A::static_new();
+    let _ = a.keyword_let();
+    let _ = namespace_new();
+    let _ = r#await();
+    std::hint::black_box(&TRUE);
+
+    let _ = Menu::new();
+}
+
+// Exports with keywords that we allow and are renamed automatically.
+
+#[wasm_bindgen]
+pub fn function() {}
+
+#[wasm_bindgen(js_name = "var")]
+pub fn sane_name() {}
+
+#[wasm_bindgen]
+pub fn weird_arguments(new: u32, var: u32, r#switch: u32, default: u32, arguments: u32) {}

crates/cli/tests/reference/keyword.wat

@@ -0,0 +1,20 @@
+(module $reference_test.wasm
+  (type (;0;) (func))
+  (type (;1;) (func (param i32 i32 i32 i32 i32)))
+  (import "./reference_test_bg.js" "__wbindgen_init_externref_table" (func (;0;) (type 0)))
+  (func $weird_arguments (;1;) (type 1) (param i32 i32 i32 i32 i32))
+  (func $exported (;2;) (type 0))
+  (func $_function (;3;) (type 0))
+  (func $_var (;4;) (type 0))
+  (table (;0;) 128 externref)
+  (memory (;0;) 17)
+  (export "memory" (memory 0))
+  (export "exported" (func $exported))
+  (export "_function" (func $_function))
+  (export "_var" (func $_var))
+  (export "weird_arguments" (func $weird_arguments))
+  (export "__wbindgen_export_0" (table 0))
+  (export "__wbindgen_start" (func 0))
+  (@custom "target_features" (after code) "\04+\0amultivalue+\0fmutable-globals+\0freference-types+\08sign-ext")
+)
+