Merge pull request #380 from akryvomaz/master

bindings for Generator.next(), Generator.return() and Generator.throw()

src/js.rs

@@ -369,6 +369,32 @@ extern "C" {
     pub fn to_string(this: &Function) -> JsString;
 }
 
+// Generator
+#[wasm_bindgen]
+extern {
+    pub type Generator;
+
+    /// The next() method returns an object with two properties done and value.
+    /// You can also provide a parameter to the next method to send a value to the generator.
+    ///
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator/next
+    #[wasm_bindgen(method, structural, catch)]
+    pub fn next(this: &Generator, value: &JsValue) -> Result<JsValue, JsValue>;
+
+    /// The return() method returns the given value and finishes the generator.
+    /// 
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator/return
+    #[wasm_bindgen(method, structural, js_name = return)]
+    pub fn return_(this: &Generator, value: &JsValue) -> JsValue;
+
+    /// The throw() method resumes the execution of a generator by throwing an error into it
+    /// and returns an object with two properties done and value.
+    /// 
+    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Generator/throw
+    #[wasm_bindgen(method, structural, catch)]
+    pub fn throw(this: &Generator, error: &Error) -> Result<JsValue, JsValue>;
+}
+
 // Map
 #[wasm_bindgen]
 extern {

tests/all/js_globals/Generator.rs

@@ -0,0 +1,146 @@
+#![allow(non_snake_case)]
+
+use project;
+
+#[test]
+fn return_() {
+    project()
+        .file(
+            "src/lib.rs",
+            r#"
+            #![feature(proc_macro, wasm_custom_section)]
+
+            extern crate wasm_bindgen;
+            use wasm_bindgen::prelude::*;
+            use wasm_bindgen::js;
+
+            #[wasm_bindgen]
+            pub fn gen_return(this: &js::Generator, value: &JsValue) -> JsValue {
+                this.return_(value)
+            }
+        "#,
+        )
+        .file(
+            "test.ts",
+            r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                function* generator() {
+                    yield 1;
+                    yield 2;
+                }
+
+                const gen = generator();
+                gen.next();
+
+                const res = wasm.gen_return(gen, 42);
+                assert.deepEqual(res, { value: 42, done: true });
+
+                const next = gen.next();
+                assert.deepEqual(next, { value: undefined, done: true });
+            }
+        "#,
+        )
+        .test()
+}
+
+#[test]
+fn next() {
+    project()
+        .file(
+            "src/lib.rs",
+            r#"
+            #![feature(proc_macro, wasm_custom_section)]
+
+            extern crate wasm_bindgen;
+            use wasm_bindgen::prelude::*;
+            use wasm_bindgen::js;
+
+            #[wasm_bindgen]
+            pub fn next(this: &js::Generator, value: &JsValue) -> JsValue {
+                this.next(value)
+                    .ok()
+                    .expect("generator throws an error")
+            }
+
+            #[wasm_bindgen]
+            pub fn next_throws_error(this: &js::Generator, value: &JsValue) -> bool {
+                this.next(value).is_err()
+            }
+        "#,
+        )
+        .file(
+            "test.ts",
+            r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                function* generator() {
+                    const reply = yield '2 * 2';
+
+                    return reply === 4;
+                }
+
+                const gen = generator();
+
+                const q = wasm.next(gen, undefined);
+                assert.deepEqual(q, { value: '2 * 2', done: false });
+
+                const a = wasm.next(gen, 4);
+                assert.deepEqual(a, { value: true, done: true });
+
+                function* brokenGenerator() {
+                    throw new Error('Something went wrong');
+                    yield 1;
+                }
+
+                assert(wasm.next_throws_error(brokenGenerator(), undefined));
+            }
+        "#,
+        )
+        .test()
+}
+
+#[test]
+fn throw() {
+    project()
+        .file(
+            "src/lib.rs",
+            r#"
+            #![feature(proc_macro, wasm_custom_section)]
+
+            extern crate wasm_bindgen;
+            use wasm_bindgen::prelude::*;
+            use wasm_bindgen::js;
+
+            #[wasm_bindgen]
+            pub fn gen_throws_error(this: &js::Generator, error: &js::Error) -> bool {
+                this.throw(error).is_err()
+            }
+        "#,
+        )
+        .file(
+            "test.ts",
+            r#"
+            import * as assert from "assert";
+            import * as wasm from "./out";
+
+            export function test() {
+                function* generator() {
+                    yield 1;
+                    yield 2;
+                }
+
+                const gen = generator();
+                gen.next();
+
+                assert(wasm.gen_throws_error(gen, new Error('Something went wrong')));
+                assert.deepEqual(gen.next(), { value: undefined, done: true });
+            }
+        "#,
+        )
+        .test()
+}

tests/all/js_globals/mod.rs

@@ -8,6 +8,7 @@ mod Boolean;
 mod Date;
 mod Error;
 mod Function;
+mod Generator;
 mod JsString;
 mod Map;
 mod MapIterator;