Merge pull request #70 from Healthire/struct-into-js

Support passing custom types by value into JS imports

crates/wasm-bindgen-cli-support/src/js.rs

@@ -1402,6 +1402,17 @@ impl<'a, 'b> SubContext<'a, 'b> {
                     invoc_args.push(format!("getObject(arg{})", i));
                     abi_args.push(format!("arg{}", i));
                 }
+                custom if (custom as u32) & shared::TYPE_CUSTOM_REF_FLAG == 0 => {
+                    let s = self.cx.custom_type_name(custom).to_string();
+                    abi_args.push(format!("ptr{}", i));
+                    let assign = if self.cx.config.debug {
+                        format!("let arg{0} = new {class}(ptr{0}, token);", i, class = s)
+                    } else {
+                        format!("let arg{0} = new {class}(ptr{0});", i, class = s)
+                    };
+                    extra.push_str(&assign);
+                    invoc_args.push(format!("arg{}", i));
+                }
                 _ => {
                     panic!("unsupported type in import");
                 }

tests/classes.rs

@@ -225,6 +225,53 @@ fn pass_one_to_another() {
         .test();
 }
 
+#[test]
+fn pass_into_js() {
+    test_support::project()
+        .file("src/lib.rs", r#"
+            #![feature(proc_macro)]
+
+            extern crate wasm_bindgen;
+
+            use wasm_bindgen::prelude::*;
+
+            #[wasm_bindgen]
+            pub struct Foo(i32);
+
+            #[wasm_bindgen]
+            impl Foo {
+                pub fn inner(&self) -> i32 {
+                    self.0
+                }
+            }
+
+            #[wasm_bindgen(module = "./test")]
+            extern {
+                fn take_foo(foo: Foo);
+            }
+
+            #[wasm_bindgen]
+            pub fn run() {
+                take_foo(Foo(13));
+            }
+        "#)
+        .file("test.ts", r#"
+            import { run, Foo } from "./out";
+            import * as assert from "assert";
+
+            export function take_foo(foo: Foo) {
+                assert.strictEqual(foo.inner(), 13);
+                foo.free();
+                assert.throws(() => foo.free(), /null pointer passed to rust/);
+            }
+
+            export function test() {
+                run();
+            }
+        "#)
+        .test();
+}
+
 #[test]
 fn issue_27() {
     test_support::project()