Updates to AssemblyScript 0.21 which no longer includes WASI (#776)

This updates to AssemblyScript 0.21 which no longer includes WASI. This
updates guidance to use the shim, which I verified works.

Signed-off-by: Adrian Cole <adrian@tetrate.io>

assemblyscript/assemblyscript.go

@@ -12,15 +12,16 @@
 //   - "seed" - uses wazero.ModuleConfig WithRandSource as the source of seed
 //     values.
 //
+// See https://www.assemblyscript.org/concepts.html#special-imports
+//
 // # Relationship to WASI
 //
-// A program compiled to use WASI, via "import wasi" in any file, won't import
-// these functions.
+// AssemblyScript supports compiling JavaScript functions that use I/O, such
+// as `console.log("hello")`. However, WASI is not built-in to AssemblyScript.
+// Use the `wasi-shim` to compile if you get import errors.
 //
-// See wasi_snapshot_preview1.Instantiate and
-//   - https://www.assemblyscript.org/concepts.html#special-imports
-//   - https://www.assemblyscript.org/concepts.html#targeting-wasi
-//   - https://www.assemblyscript.org/compiler.html#compiler-options
+// See https://github.com/AssemblyScript/wasi-shim#usage and
+// wasi_snapshot_preview1.Instantiate for more.
 package assemblyscript
 
 import (

examples/assemblyscript/README.md

@@ -13,5 +13,13 @@ Ex.
 ```bash
 $ go run assemblyscript.go 7
 hello_world returned: 10
-sad sad world at assemblyscript.ts:7:3
+sad sad world at index.ts:7:3
 ```
+
+Note: [index.ts](testdata/index.ts) avoids use of JavaScript functions that use
+I/O, such as [console.log][1]. If your code uses these, compile your code with
+the [wasi-shim][2] and configure in wazero using
+`wasi_snapshot_preview1.Instantiate`.
+
+[1]: https://github.com/AssemblyScript/assemblyscript/blob/v0.21.2/std/assembly/bindings/dom.ts#L143
+[2]: https://github.com/AssemblyScript/wasi-shim#usage

examples/assemblyscript/assemblyscript.go

@@ -14,7 +14,7 @@ import (
 
 // asWasm compiled using `npm install && npm run build`
 //
-//go:embed testdata/assemblyscript.wasm
+//go:embed testdata/index.wasm
 var asWasm []byte
 
 // main shows how to interact with a WebAssembly function that was compiled

examples/assemblyscript/assemblyscript_test.go

@@ -13,5 +13,5 @@ import (
 func Test_main(t *testing.T) {
 	stdout, stderr := maintester.TestMain(t, main, "assemblyscript", "7")
 	require.Equal(t, "hello_world returned: 10", stdout)
-	require.Equal(t, "sad sad world at assemblyscript.ts:7:3\n", stderr)
+	require.Equal(t, "sad sad world at index.ts:7:3\n", stderr)
 }

examples/assemblyscript/testdata/package.json

@@ -2,9 +2,9 @@
   "name": "hello-assemblyscript",
   "version": "0.0.1",
   "scripts": {
-    "build": "asc assemblyscript.ts --debug -b none -o assemblyscript.wasm"
+    "build": "asc index.ts --debug -b none -o index.wasm"
   },
   "devDependencies": {
-    "assemblyscript": "^0.20.6"
+    "assemblyscript": "^0.21.2"
   }
 }