fix(es/transforms): Fix bugs (swc-project#1795)

swc_ecma_transforms_compat:
 - `async_to_generator`: Handle await in async generators correctly. (swc-project#1752)

swc_ecma_transforms_module:
 - Don't panic on double import from one module. (swc-project#1757)

ecmascript/transforms/base/tests/ts-resolver/tsc/generatedContextualTyping/1/input.ts

@@ -0,0 +1,3 @@
+class x87 { constructor(parm: () => Base[] = function named() { return [d1, d2] }) { } }
+
+class x90 { constructor(parm: { (): Base[]; } = function named() { return [d1, d2] }) { } }

ecmascript/transforms/base/tests/ts-resolver/tsc/generatedContextualTyping/1/output.ts

@@ -0,0 +1,14 @@
+class x87 {
+    constructor(parm__2: () => Base[] = function named__3() {
+        return [d1, d2];
+    }){
+    }
+}
+class x90 {
+    constructor(parm__4: {
+        () : Base[];
+    } = function named__5() {
+        return [d1, d2];
+    }){
+    }
+}

ecmascript/transforms/compat/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "swc_ecma_transforms_compat"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.17.9"
+version = "0.17.10"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]

ecmascript/transforms/compat/src/es2017/async_to_generator.rs

@@ -866,7 +866,9 @@ impl Actual {
 ///
 /// `_asyncToGenerator(function*() {})` from `async function() {}`;
 fn make_fn_ref(mut expr: FnExpr, should_not_bind_this: bool) -> Expr {
-    expr.function.body = expr.function.body.fold_with(&mut AsyncFnBodyHandler);
+    expr.function.body = expr.function.body.fold_with(&mut AsyncFnBodyHandler {
+        is_async_generator: expr.function.is_generator,
+    });
 
     assert!(expr.function.is_async);
     expr.function.is_async = false;
@@ -901,7 +903,9 @@ fn make_fn_ref(mut expr: FnExpr, should_not_bind_this: bool) -> Expr {
     })
 }
 
-struct AsyncFnBodyHandler;
+struct AsyncFnBodyHandler {
+    is_async_generator: bool,
+}
 
 macro_rules! noop {
     ($name:ident, $T:path) => {
@@ -924,11 +928,28 @@ impl Fold for AsyncFnBodyHandler {
         let expr = expr.fold_children_with(self);
 
         match expr {
-            Expr::Await(AwaitExpr { span, arg }) => Expr::Yield(YieldExpr {
-                span,
-                delegate: false,
-                arg: Some(arg),
-            }),
+            Expr::Await(AwaitExpr { span, arg }) => {
+                if self.is_async_generator {
+                    let callee = helper!(await_async_generator, "awaitAsyncGenerator");
+                    let arg = Box::new(Expr::Call(CallExpr {
+                        span,
+                        callee,
+                        args: vec![arg.as_arg()],
+                        type_args: Default::default(),
+                    }));
+                    Expr::Yield(YieldExpr {
+                        span,
+                        delegate: false,
+                        arg: Some(arg),
+                    })
+                } else {
+                    Expr::Yield(YieldExpr {
+                        span,
+                        delegate: false,
+                        arg: Some(arg),
+                    })
+                }
+            }
             _ => expr,
         }
     }

ecmascript/transforms/compat/tests/es2017_async_to_generator.rs

@@ -2612,3 +2612,31 @@ test!(
     }
     "
 );
+
+test_exec!(
+    syntax(),
+    |_| async_to_generator(),
+    issue_1752_1,
+    "
+    async function* generate() {
+      const results = await Promise.all([
+        Promise.resolve(1),
+        Promise.resolve(2),
+        Promise.resolve(3),
+      ])
+      for (const result of results) {
+        console.log(`yield ${result}`)
+        yield result
+      }
+    }
+    
+    async function printValues() {
+      const iterator = generate()
+      for await (const value of iterator) {
+        console.log(`iterator value: ${value}`)
+      }
+    }
+    
+    printValues()
+    "
+);

ecmascript/transforms/module/Cargo.toml

@@ -6,7 +6,7 @@ edition = "2018"
 license = "Apache-2.0/MIT"
 name = "swc_ecma_transforms_module"
 repository = "https://github.com/swc-project/swc.git"
-version = "0.17.1"
+version = "0.17.2"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]

ecmascript/transforms/module/src/util.rs

@@ -318,6 +318,14 @@ impl Scope {
         } else {
             self.imports
                 .entry(import.src.value.clone())
+                .and_modify(|opt| {
+                    if opt.is_none() {
+                        *opt = Some((
+                            local_name_for_src(&import.src.value),
+                            import.src.span.apply_mark(Mark::fresh(Mark::root())),
+                        ));
+                    }
+                })
                 .or_insert_with(|| {
                     Some((
                         local_name_for_src(&import.src.value),

ecmascript/transforms/module/tests/common_js.rs

@@ -4765,3 +4765,20 @@ test!(
     });
     "
 );
+
+test!(
+    syntax(),
+    |_| tr(Default::default()),
+    issue_1757_1,
+    "
+    import 'testlibrary';
+    import { aFunc } from 'testlibrary';
+
+    console.log('aFunc: ', aFunc(1,2));
+    ",
+    "
+    'use strict';
+    var _testlibrary = require('testlibrary');
+    console.log('aFunc: ', (0, _testlibrary).aFunc(1, 2));
+    "
+);

tests/fixture/issue-1752/case1/input/.swcrc

@@ -0,0 +1,8 @@
+{
+    "jsc": {
+        "parser": {
+            "syntax": "typescript"
+        },
+        "target": "es2017"
+    }
+}

tests/fixture/issue-1752/case1/input/index.js

@@ -0,0 +1,20 @@
+async function* generate() {
+    const results = await Promise.all([
+        Promise.resolve(1),
+        Promise.resolve(2),
+        Promise.resolve(3),
+    ])
+    for (const result of results) {
+        console.log(`yield ${result}`)
+        yield result
+    }
+}
+
+async function printValues() {
+    const iterator = generate()
+    for await (const value of iterator) {
+        console.log(`iterator value: ${value}`)
+    }
+}
+
+printValues()

tests/fixture/issue-1752/case1/output/index.js

@@ -0,0 +1,184 @@
+function AsyncGenerator(gen) {
+    var front, back;
+    function send(key, arg) {
+        return new Promise(function(resolve, reject) {
+            var request = {
+                key: key,
+                arg: arg,
+                resolve: resolve,
+                reject: reject,
+                next: null
+            };
+            if (back) {
+                back = back.next = request;
+            } else {
+                front = back = request;
+                resume(key, arg);
+            }
+        });
+    }
+    function resume(key, arg) {
+        try {
+            var result = gen[key](arg);
+            var value = result.value;
+            var wrappedAwait = value instanceof _AwaitValue;
+            Promise.resolve(wrappedAwait ? value.wrapped : value).then(function(arg) {
+                if (wrappedAwait) {
+                    resume("next", arg);
+                    return;
+                }
+                settle(result.done ? "return" : "normal", arg);
+            }, function(err) {
+                resume("throw", err);
+            });
+        } catch (err) {
+            settle("throw", err);
+        }
+    }
+    function settle(type, value) {
+        switch(type){
+            case "return":
+                front.resolve({
+                    value: value,
+                    done: true
+                });
+                break;
+            case "throw":
+                front.reject(value);
+                break;
+            default:
+                front.resolve({
+                    value: value,
+                    done: false
+                });
+                break;
+        }
+        front = front.next;
+        if (front) {
+            resume(front.key, front.arg);
+        } else {
+            back = null;
+        }
+    }
+    this._invoke = send;
+    if (typeof gen.return !== "function") {
+        this.return = undefined;
+    }
+}
+if (typeof Symbol === "function" && Symbol.asyncIterator) {
+    AsyncGenerator.prototype[Symbol.asyncIterator] = function() {
+        return this;
+    };
+}
+AsyncGenerator.prototype.next = function(arg) {
+    return this._invoke("next", arg);
+};
+AsyncGenerator.prototype.throw = function(arg) {
+    return this._invoke("throw", arg);
+};
+AsyncGenerator.prototype.return = function(arg) {
+    return this._invoke("return", arg);
+};
+function _asyncIterator(iterable) {
+    var method;
+    if (typeof Symbol === "function") {
+        if (Symbol.asyncIterator) {
+            method = iterable[Symbol.asyncIterator];
+            if (method != null) return method.call(iterable);
+        }
+        if (Symbol.iterator) {
+            method = iterable[Symbol.iterator];
+            if (method != null) return method.call(iterable);
+        }
+    }
+    throw new TypeError("Object is not async iterable");
+}
+function asyncGeneratorStep(gen, resolve, reject, _next, _throw, key, arg) {
+    try {
+        var info = gen[key](arg);
+        var value = info.value;
+    } catch (error) {
+        reject(error);
+        return;
+    }
+    if (info.done) {
+        resolve(value);
+    } else {
+        Promise.resolve(value).then(_next, _throw);
+    }
+}
+function _asyncToGenerator(fn) {
+    return function() {
+        var self = this, args = arguments;
+        return new Promise(function(resolve, reject) {
+            var gen = fn.apply(self, args);
+            function _next(value) {
+                asyncGeneratorStep(gen, resolve, reject, _next, _throw, "next", value);
+            }
+            function _throw(err) {
+                asyncGeneratorStep(gen, resolve, reject, _next, _throw, "throw", err);
+            }
+            _next(undefined);
+        });
+    };
+}
+function _awaitAsyncGenerator(value) {
+    return new _AwaitValue(value);
+}
+function _AwaitValue(value) {
+    this.wrapped = value;
+}
+function _wrapAsyncGenerator(fn) {
+    return function() {
+        return new AsyncGenerator(fn.apply(this, arguments));
+    };
+}
+function _generate() {
+    _generate = _wrapAsyncGenerator(function*() {
+        const results = yield _awaitAsyncGenerator(Promise.all([
+            Promise.resolve(1),
+            Promise.resolve(2),
+            Promise.resolve(3), 
+        ]));
+        for (const result of results){
+            console.log(`yield ${result}`);
+            yield result;
+        }
+    });
+    return _generate.apply(this, arguments);
+}
+function generate() {
+    return _generate.apply(this, arguments);
+}
+function _printValues() {
+    _printValues = _asyncToGenerator(function*() {
+        const iterator = generate();
+        {
+            var _iteratorNormalCompletion = true, _didIteratorError = false, _iteratorError;
+            try {
+                for(var _iterator = _asyncIterator(iterator), _step, _value; _step = yield _iterator.next(), _iteratorNormalCompletion = _step.done, _value = yield _step.value, !_iteratorNormalCompletion; _iteratorNormalCompletion = true){
+                    const value = _value;
+                    console.log(`iterator value: ${value}`);
+                }
+            } catch (err) {
+                _didIteratorError = true;
+                _iteratorError = err;
+            } finally{
+                try {
+                    if (!_iteratorNormalCompletion && _iterator.return != null) {
+                        yield _iteratorError.return();
+                    }
+                } finally{
+                    if (_didIteratorError) {
+                        throw _iteratorError;
+                    }
+                }
+            }
+        }
+    });
+    return _printValues.apply(this, arguments);
+}
+function printValues() {
+    return _printValues.apply(this, arguments);
+}
+printValues();

tests/fixture/issue-1757/case1/input/.swcrc

@@ -0,0 +1,5 @@
+{
+    "module": {
+        "type": "commonjs"
+    }
+}

tests/fixture/issue-1757/case1/input/index.js

@@ -0,0 +1,4 @@
+import "testlibrary";
+import { aFunc } from "testlibrary";
+
+console.log("aFunc: ", aFunc(1, 2));

tests/fixture/issue-1757/case1/output/index.js

@@ -0,0 +1,3 @@
+"use strict";
+var _testlibrary = require("testlibrary");
+console.log("aFunc: ", (0, _testlibrary).aFunc(1, 2));