address pr comments

Author: jakobhellermann

Cargo.toml

@@ -65,6 +65,7 @@ members = [
   "examples/char",
   "examples/closures",
   "examples/console_log",
+  "examples/deno",
   "examples/dom",
   "examples/duck-typed-interfaces",
   "examples/fetch",

azure-pipelines.yml

@@ -167,7 +167,7 @@ jobs:
       - script: mv _package.json package.json && npm install && rm package.json
         displayName: "run npm install"
       - script: |
-          for dir in `ls examples | grep -v README | grep -v asm.js | grep -v raytrace | grep -v without-a-bundler | grep -v websockets | grep -v webxr`; do
+          for dir in `ls examples | grep -v README | grep -v asm.js | grep -v raytrace | grep -v without-a-bundler | grep -v websockets | grep -v webxr | grep -v deno`; do
             (cd examples/$dir &&
             ln -fs ../../node_modules . &&
             npm run build -- --output-path $BUILD_ARTIFACTSTAGINGDIRECTORY/exbuild/$dir) || exit 1;
@@ -178,6 +178,16 @@ jobs:
           artifactName: examples1
           targetPath: '$(Build.ArtifactStagingDirectory)'
 
+  - job: test_deno
+    displayName: "Build and test the deno example"
+    steps:
+      - template: ci/azure-install-rust.yml
+      - script: rustup target add wasm32-unknown-unknown
+        displayName: "install wasm target"
+      - template: ci/azure-install-deno.yml
+      - script: cd examples/deno && ./build.sh && $HOME/.deno/bin/deno run --allow-read test.ts
+        displayName: "build and run deno example"
+
   - job: build_raytrace
     displayName: "Build raytrace examples"
     steps:

ci/azure-install-deno.yml

@@ -0,0 +1,3 @@
+steps:
+  - script: curl -fsSL https://deno.land/x/install/install.sh | sh
+    displayName: "install deno"

crates/cli-support/src/js/mod.rs

@@ -294,6 +294,8 @@ impl<'a> Context<'a> {
     }
 
     fn generate_deno_wasm_loading(&self, module_name: &str) -> String {
+        // Deno removed support for .wasm imports in https://github.com/denoland/deno/pull/5135
+        // the issue for bringing it back is https://github.com/denoland/deno/issues/5609.
         format!(
             "const file = new URL(import.meta.url).pathname;
             const wasmFile = file.substring(0, file.lastIndexOf(Deno.build.os === 'windows' ? '\\\\' : '/') + 1) + '{}_bg.wasm';
@@ -1283,27 +1285,36 @@ impl<'a> Context<'a> {
     }
 
     fn expose_text_processor(&mut self, s: &str, args: &str) -> Result<(), Error> {
-        if self.config.mode.nodejs() {
-            let name = self.import_name(&JsImport {
-                name: JsImportName::Module {
-                    module: "util".to_string(),
-                    name: s.to_string(),
-                },
-                fields: Vec::new(),
-            })?;
-            self.global(&format!("let cached{} = new {}{};", s, name, args));
-        } else if !self.config.mode.always_run_in_browser() && !self.config.mode.deno() {
-            self.global(&format!(
-                "
+        match &self.config.mode {
+            OutputMode::Node { .. } => {
+                let name = self.import_name(&JsImport {
+                    name: JsImportName::Module {
+                        module: "util".to_string(),
+                        name: s.to_string(),
+                    },
+                    fields: Vec::new(),
+                })?;
+                self.global(&format!("let cached{} = new {}{};", s, name, args));
+            }
+            OutputMode::Bundler {
+                browser_only: false,
+            } => {
+                self.global(&format!(
+                    "
                     const l{0} = typeof {0} === 'undefined' ? \
                         (0, module.require)('util').{0} : {0};\
                 ",
-                s
-            ));
-            self.global(&format!("let cached{0} = new l{0}{1};", s, args));
-        } else {
-            self.global(&format!("let cached{0} = new {0}{1};", s, args));
-        }
+                    s
+                ));
+                self.global(&format!("let cached{0} = new l{0}{1};", s, args));
+            }
+            OutputMode::Deno
+            | OutputMode::Web
+            | OutputMode::NoModules { .. }
+            | OutputMode::Bundler { browser_only: true } => {
+                self.global(&format!("let cached{0} = new {0}{1};", s, args))
+            }
+        };
 
         Ok(())
     }

crates/cli-support/src/lib.rs

@@ -564,29 +564,13 @@ impl OutputMode {
         }
     }
 
-    fn always_run_in_browser(&self) -> bool {
-        match self {
-            OutputMode::Web => true,
-            OutputMode::NoModules { .. } => true,
-            OutputMode::Bundler { browser_only } => *browser_only,
-            _ => false,
-        }
-    }
-
     fn web(&self) -> bool {
         match self {
             OutputMode::Web => true,
             _ => false,
         }
     }
 
-    fn deno(&self) -> bool {
-        match self {
-            OutputMode::Deno { .. } => true,
-            _ => false,
-        }
-    }
-
     fn esm_integration(&self) -> bool {
         match self {
             OutputMode::Bundler { .. }

examples/deno/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "deno"
+version = "0.1.0"
+authors = ["The wasm-bindgen Developers"]
+edition = "2018"
+
+[lib]
+crate-type = ["cdylib"]
+
+[dependencies]
+wasm-bindgen = "0.2.63"

examples/deno/README.md

@@ -0,0 +1,16 @@
+# Using deno
+
+You can build the example with
+
+```sh
+$ ./build.sh
+```
+
+and test it with
+
+```sh
+$ deno run --allow-read test.ts
+```
+
+The `--allow-read` flag is needed because the wasm file is read during runtime.
+This will be fixed when https://github.com/denoland/deno/issues/5609 is resolved.

examples/deno/build.sh

@@ -0,0 +1,7 @@
+#!/bin/sh
+
+set -eux
+
+cargo build --target wasm32-unknown-unknown --release
+cargo run --package wasm-bindgen-cli --bin wasm-bindgen -- \
+	--out-dir pkg --target deno ${CARGO_TARGET_DIR:-../../target}/wasm32-unknown-unknown/release/deno.wasm

examples/deno/crate/.gitignore

@@ -0,0 +1 @@
+/deno.wasm

examples/deno/defined-in-js.js

@@ -0,0 +1,17 @@
+export class MyClass {
+  constructor() {
+    this._number = 42;
+  }
+
+  get number() {
+    return this._number;
+  }
+
+  set number(n) {
+    return (this._number = n);
+  }
+
+  render() {
+    return `My number is: ${this.number}`;
+  }
+}

examples/deno/src/lib.rs

@@ -0,0 +1,37 @@
+use wasm_bindgen::prelude::*;
+
+#[wasm_bindgen(module = "/defined-in-js.js")]
+extern "C" {
+    type MyClass;
+
+    #[wasm_bindgen(constructor)]
+    fn new() -> MyClass;
+
+    #[wasm_bindgen(method, getter)]
+    fn number(this: &MyClass) -> u32;
+    #[wasm_bindgen(method, setter)]
+    fn set_number(this: &MyClass, number: u32) -> MyClass;
+    #[wasm_bindgen(method)]
+    fn render(this: &MyClass) -> String;
+}
+
+// lifted from the `console_log` example
+#[wasm_bindgen]
+extern "C" {
+    #[wasm_bindgen(js_namespace = console)]
+    fn log(s: &str);
+}
+
+#[wasm_bindgen(inline_js = "export function add(a, b) { return a + b; }")]
+extern "C" {
+    fn add(a: u32, b: u32) -> u32;
+}
+
+#[wasm_bindgen]
+pub fn greet(name: String) {
+    log(&format!("Hello from {}!", name)); // should output "Hello from Rust!"
+
+    let x = MyClass::new();
+    assert_eq!(x.number(), add(40, 2));
+    log(&x.render());
+}

examples/deno/test.ts

@@ -0,0 +1,3 @@
+import { greet } from "./pkg/deno.js";
+
+greet("Deno");

guide/src/reference/deployment.md

@@ -14,12 +14,14 @@ should behave the same way in this respect. The values possible here are:
 | [`bundler`]     | Suitable for loading in bundlers like Webpack              |
 | [`web`]         | Directly loadable in a web browser                         |
 | [`nodejs`]      | Loadable via `require` as a Node.js module                 |
+| [`deno`]        | Loadable using imports from Deno modules                   |
 | [`no-modules`]  | Like `web`, but older and doesn't use ES modules           |
 
 [`bundler`]: #bundlers
 [`web`]: #without-a-bundler
 [`no-modules`]: #without-a-bundler
 [`nodejs`]: #nodejs
+[`deno`]: #Deno
 
 ## Bundlers
 
@@ -69,7 +71,7 @@ documentation, but the highlights of this output are:
 The CLI also supports an output mode called `--target no-modules` which is
 similar to the `web` target in that it requires manual initialization of the
 wasm and is intended to be included in web pages without any further
-postprocessing.  See the [without a bundler example][nomex] for some more
+postprocessing. See the [without a bundler example][nomex] for some more
 information about `--target no-modules`.
 
 ## Node.js
@@ -88,6 +90,18 @@ as it has a JS shim generated as well).
 Note that this method requires a version of Node.js with WebAssembly support,
 which is currently Node 8 and above.
 
+## Deno
+
+**`--target deno`**
+
+To deploy WebAssembly to Deno, use the `--target deno` flag.
+To then import your module inside deno, use
+
+```ts
+// @deno-types="./out/crate_name.d.ts"
+import { yourFunction } from "./out/crate_name.js";
+```
+
 ## NPM
 
 If you'd like to deploy compiled WebAssembly to NPM, then the tool for the job