From 55d40a6c2a7b054df9bae45d231a2b8ef73d1eed Mon Sep 17 00:00:00 2001
From: Maxim Schuwalow <maxim.schuwalow@gmail.com>
Date: Wed, 29 Jan 2025 23:54:54 +0100
Subject: [PATCH] javascript example working

---
 examples/js/js-default-wasi-http/.gitignore   |  3 ++
 .../js/js-default-wasi-http/metadata.json     |  9 ++++
 examples/js/js-default-wasi-http/package.json | 15 ++++++
 .../js/js-default-wasi-http/rollup.config.mjs | 11 +++++
 examples/js/js-default-wasi-http/src/main.js  | 47 +++++++++++++++++++
 examples/js/js-default-wasi-http/wit/main.wit |  8 ++++
 6 files changed, 93 insertions(+)
 create mode 100644 examples/js/js-default-wasi-http/.gitignore
 create mode 100644 examples/js/js-default-wasi-http/metadata.json
 create mode 100644 examples/js/js-default-wasi-http/package.json
 create mode 100644 examples/js/js-default-wasi-http/rollup.config.mjs
 create mode 100644 examples/js/js-default-wasi-http/src/main.js
 create mode 100644 examples/js/js-default-wasi-http/wit/main.wit

diff --git a/examples/js/js-default-wasi-http/.gitignore b/examples/js/js-default-wasi-http/.gitignore
new file mode 100644
index 0000000..4bded1c
--- /dev/null
+++ b/examples/js/js-default-wasi-http/.gitignore
@@ -0,0 +1,3 @@
+node_modules/
+out/
+src/generated/
diff --git a/examples/js/js-default-wasi-http/metadata.json b/examples/js/js-default-wasi-http/metadata.json
new file mode 100644
index 0000000..8469293
--- /dev/null
+++ b/examples/js/js-default-wasi-http/metadata.json
@@ -0,0 +1,9 @@
+{
+  "description": "A simple stateful Golem worker implemented in JavaScript with no dependencies on external services",
+  "requiresAdapter": false,
+  "requiresWASI": true,
+  "exclude": [
+    "node_modules",
+    "out"
+  ]
+}
diff --git a/examples/js/js-default-wasi-http/package.json b/examples/js/js-default-wasi-http/package.json
new file mode 100644
index 0000000..d0315f2
--- /dev/null
+++ b/examples/js/js-default-wasi-http/package.json
@@ -0,0 +1,15 @@
+{
+  "scripts": {
+    "build": "rollup --config",
+    "componentize": "npm run build && jco componentize -w wit -o out/component_name.wasm out/main.js",
+    "clean": "rm -rf out src/generated",
+    "serve": "jco serve out/component_name.wasm"
+  },
+  "devDependencies": {
+    "@golemcloud/componentize-js": "0.10.5-golem.3",
+    "@golemcloud/golem-ts": "1.1.1",
+    "@golemcloud/jco": "1.4.4-golem.1",
+    "@rollup/plugin-node-resolve": "^15.2.3",
+    "rollup": "^4.18.0"
+  }
+}
diff --git a/examples/js/js-default-wasi-http/rollup.config.mjs b/examples/js/js-default-wasi-http/rollup.config.mjs
new file mode 100644
index 0000000..7b7efc1
--- /dev/null
+++ b/examples/js/js-default-wasi-http/rollup.config.mjs
@@ -0,0 +1,11 @@
+import resolve from "@rollup/plugin-node-resolve";
+
+export default {
+  input: "src/main.js",
+  output: {
+    file: "out/main.js",
+    format: "esm",
+  },
+  external: ["wasi:http/types@0.2.0"],
+  plugins: [resolve()],
+};
diff --git a/examples/js/js-default-wasi-http/src/main.js b/examples/js/js-default-wasi-http/src/main.js
new file mode 100644
index 0000000..4cecb96
--- /dev/null
+++ b/examples/js/js-default-wasi-http/src/main.js
@@ -0,0 +1,47 @@
+import {
+    ResponseOutparam,
+    OutgoingBody,
+    OutgoingResponse,
+    Fields,
+  } from 'wasi:http/types@0.2.0';
+
+// For a detailed guide see https://github.com/bytecodealliance/jco/tree/main/examples/components/http-hello-world
+
+/**
+ * This export represents the `wasi:http/incoming-handler` interface,
+ * which describes implementing a HTTP handler in WebAssembly using WASI types.
+ */
+export const incomingHandler = {
+    /**
+     * This Javascript will be turned into a WebAssembly component by `jco` and turned into a
+     * WebAssembly binary with a single export (this `handler` function).
+     *
+     * The exported `handle` method is part of the `wasi:http/incoming-handler` interface,
+     * which defines how to hadle incoming web requests, turning this component into one that can
+     * serve web requests.
+     */
+    handle: function (incomingRequest, responseOutparam) {
+        // Start building an outgoing response
+        const outgoingResponse = new OutgoingResponse(new Fields());
+
+        // Access the outgoing response body
+        let outgoingBody = outgoingResponse.body();
+        {
+            // Create a stream for the response body
+            let outputStream = outgoingBody.write();
+            // Write hello world to the response stream
+            outputStream.blockingWriteAndFlush(
+                new Uint8Array(new TextEncoder().encode('Hello from Javascript!\n'))
+            );
+            // @ts-ignore: This is required in order to dispose the stream before we return
+            outputStream[Symbol.dispose]();
+        }
+
+        // Set the status code for the response
+        outgoingResponse.setStatusCode(200);
+        // Finish the response body
+        OutgoingBody.finish(outgoingBody, undefined);
+        // Set the created response to an "OK" Result<T> value
+        ResponseOutparam.set(outgoingResponse, { tag: 'ok', val: outgoingResponse });
+    },
+}
diff --git a/examples/js/js-default-wasi-http/wit/main.wit b/examples/js/js-default-wasi-http/wit/main.wit
new file mode 100644
index 0000000..f3c4c9c
--- /dev/null
+++ b/examples/js/js-default-wasi-http/wit/main.wit
@@ -0,0 +1,8 @@
+package pack:name;
+
+// See https://component-model.bytecodealliance.org/design/wit.html for more details about the WIT syntax
+// See https://github.com/WebAssembly/wasi-http for an introduction to wasi-http
+
+world component-name {
+  export wasi:http/incoming-handler@0.2.0;
+}