From fb2a04d07e7e59c155af7539d7cf0d6fce5e3205 Mon Sep 17 00:00:00 2001
From: Peter Donovan <peter@xronos.com>
Date: Mon, 4 Mar 2024 15:03:52 -0800
Subject: [PATCH] Get wasm to build.

---
 package.json    |  2 +-
 src/tsbuild.mjs | 67 +++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 68 insertions(+), 1 deletion(-)
 create mode 100644 src/tsbuild.mjs

diff --git a/package.json b/package.json
index ef4ba4f37..7cdc6238b 100644
--- a/package.json
+++ b/package.json
@@ -186,7 +186,7 @@
     },
     "scripts": {
         "clean": "rimraf out && rimraf lib && rimraf vscode-lingua-franca-*.vsix",
-        "esbuild-base": "esbuild ./src/extension.ts --bundle --outfile=out/extension.js --external:vscode --format=cjs --platform=node",
+        "esbuild-base": "node src/tsbuild.mjs",
         "vscode:prepublish": "npm run esbuild-base -- --minify",
         "compile": "./write-version-to-file.sh src/extension_version.ts && npm run esbuild-base -- --sourcemap",
         "watch": "npm run esbuild-base -- --sourcemap --watch",
diff --git a/src/tsbuild.mjs b/src/tsbuild.mjs
new file mode 100644
index 000000000..2f6180747
--- /dev/null
+++ b/src/tsbuild.mjs
@@ -0,0 +1,67 @@
+// This JS script is needed to compile the TS code.
+
+import * as esbuild from 'esbuild';
+import path from 'node:path';
+import fs from 'node:fs';
+
+let wasmPlugin = {
+  name: 'wasm',
+  setup(build) {
+    // Resolve ".wasm" files to a path with a namespace
+    build.onResolve({ filter: /\.wasm$/ }, args => {
+      // If this is the import inside the stub module, import the
+      // binary itself. Put the path in the "wasm-binary" namespace
+      // to tell our binary load callback to load the binary file.
+      if (args.namespace === 'wasm-stub') {
+        return {
+          path: args.path,
+          namespace: 'wasm-binary',
+        };
+      }
+
+      // Otherwise, generate the JavaScript stub module for this
+      // ".wasm" file. Put it in the "wasm-stub" namespace to tell
+      // our stub load callback to fill it with JavaScript.
+      //
+      // Resolve relative paths to absolute paths here since this
+      // resolve callback is given "resolveDir", the directory to
+      // resolve imports against.
+      if (args.resolveDir === '') {
+        return; // Ignore unresolvable paths
+      }
+      return {
+        path: path.isAbsolute(args.path) ? args.path : path.join(args.resolveDir, args.path),
+        namespace: 'wasm-stub',
+      };
+    });
+
+    // Virtual modules in the "wasm-stub" namespace are filled with
+    // the JavaScript code for compiling the WebAssembly binary. The
+    // binary itself is imported from a second virtual module.
+    build.onLoad({ filter: /.*/, namespace: 'wasm-stub' }, async (args) => ({
+      contents: `import wasm from ${JSON.stringify(args.path)}
+        export default (imports) =>
+          WebAssembly.instantiate(wasm, imports).then(
+            result => result.instance.exports)`,
+    }));
+
+    // Virtual modules in the "wasm-binary" namespace contain the
+    // actual bytes of the WebAssembly file. This uses esbuild's
+    // built-in "binary" loader instead of manually embedding the
+    // binary data inside JavaScript code ourselves.
+    build.onLoad({ filter: /.*/, namespace: 'wasm-binary' }, async (args) => ({
+      contents: await fs.promises.readFile(args.path),
+      loader: 'binary',
+    }));
+  },
+};
+
+await esbuild.build({
+  entryPoints: ['./src/extension.js'],
+  bundle: true,
+  outfile: 'out/extension.js',
+  plugins: [wasmPlugin],
+  external: ['vscode'],
+  format: 'cjs',
+  platform: 'node'
+});