feat(std/wasi): add wasi_snapshot_preview1 (#6441)

.github/workflows/ci.yml

@@ -68,6 +68,12 @@ jobs:
         with:
           rust-version: 1.44.0
 
+      - name: Install rust targets
+        run: |
+          # Necessary for the std/wasi tests
+          rustup target add wasm32-unknown-unknown
+          rustup target add wasm32-wasi
+
       - name: Install clippy and rustfmt
         if: matrix.config.kind == 'lint'
         run: |

.gitignore

@@ -21,6 +21,9 @@ yarn.lock
 # yarn creates this in error.
 tools/node_modules/
 
+# compiled wasm files
+std/wasi/testdata/snapshot_preview1/
+
 # MacOS generated files
 .DS_Store
 .DS_Store?

std/wasi/README.md

@@ -0,0 +1,42 @@
+# wasi
+
+This module provides an implementation of the WebAssembly System Interface
+
+## Supported Syscalls
+
+## Usage
+
+```typescript
+import WASI from "https://deno.land/std/wasi/snapshot_preview1.ts";
+
+const wasi = new WASI({
+  args: Deno.args,
+  env: Deno.env,
+});
+
+const binary = Deno.readAll("path/to/your/module.wasm");
+const module = await WebAssembly.compile(binary);
+const instance = await WebAssembly.instantiate(module, {
+  wasi_snapshot_preview1: wasi.exports,
+});
+
+wasi.memory = module.exports.memory;
+
+if (module.exports._start) {
+  instance.exports._start();
+} else if (module.exports._initialize) {
+  instance.exports._initialize();
+} else {
+  throw new Error("No entry point found");
+}
+```
+
+## Testing
+
+The test suite for this module spawns rustc processes to compile various example
+Rust programs. You must have wasm targets enabled:
+
+```
+rustup target add wasm32-wasi
+rustup target add wasm32-unknown-unknown
+```

std/wasi/snapshot_preview1_test.ts

@@ -0,0 +1,126 @@
+/* eslint-disable */
+
+import { assert, assertEquals } from "../testing/asserts.ts";
+import * as path from "../path/mod.ts";
+import WASI from "./snapshot_preview1.ts";
+
+if (import.meta.main) {
+  const options = JSON.parse(Deno.args[0]);
+  const binary = await Deno.readFile(Deno.args[1]);
+  const module = await WebAssembly.compile(binary);
+
+  const wasi = new WASI({
+    env: options.env,
+    args: options.args,
+    preopens: options.preopens,
+  });
+
+  const instance = new WebAssembly.Instance(module, {
+    wasi_snapshot_preview1: wasi.exports,
+  });
+
+  wasi.memory = instance.exports.memory;
+
+  instance.exports._start();
+} else {
+  const rootdir = path.dirname(path.fromFileUrl(import.meta.url));
+  const testdir = path.join(rootdir, "testdata");
+  const outdir = path.join(testdir, "snapshot_preview1");
+
+  for await (const entry of Deno.readDir(testdir)) {
+    if (!entry.name.endsWith(".rs")) {
+      continue;
+    }
+
+    const process = Deno.run({
+      cmd: [
+        "rustc",
+        "--target",
+        "wasm32-wasi",
+        "--out-dir",
+        outdir,
+        path.join(testdir, entry.name),
+      ],
+      stdout: "inherit",
+      stderr: "inherit",
+    });
+
+    const status = await process.status();
+    assert(status.success);
+
+    process.close();
+
+    // TODO(caspervonb) allow the prelude to span multiple lines
+    const source = await Deno.readTextFile(path.join(testdir, entry.name));
+    const prelude = source.match(/^\/\/\s*\{.*/);
+    if (prelude) {
+      const basename = entry.name.replace(/.rs$/, ".json");
+      await Deno.writeTextFile(
+        path.join(outdir, basename),
+        prelude[0].slice(2)
+      );
+    }
+  }
+
+  for await (const entry of Deno.readDir(outdir)) {
+    if (!entry.name.endsWith(".wasm")) {
+      continue;
+    }
+
+    Deno.test(entry.name, async function () {
+      const basename = entry.name.replace(/\.wasm$/, ".json");
+      const prelude = await Deno.readTextFile(path.resolve(outdir, basename));
+      const options = JSON.parse(prelude);
+
+      const process = await Deno.run({
+        cwd: testdir,
+        cmd: [
+          `${Deno.execPath()}`,
+          "run",
+          "--quiet",
+          "--unstable",
+          "--v8-flags=--experimental-wasm-bigint",
+          "--allow-all",
+          import.meta.url,
+          prelude,
+          path.resolve(outdir, entry.name),
+        ],
+        stdin: "piped",
+        stdout: "piped",
+        stderr: "piped",
+      });
+
+      if (options.stdin) {
+        const stdin = new TextEncoder().encode(options.stdin);
+        await Deno.writeAll(process.stdin, stdin);
+      }
+
+      process.stdin.close();
+
+      const stdout = await Deno.readAll(process.stdout);
+
+      if (options.stdout) {
+        assertEquals(new TextDecoder().decode(stdout), options.stdout);
+      } else {
+        await Deno.writeAll(Deno.stdout, stdout);
+      }
+
+      process.stdout.close();
+
+      const stderr = await Deno.readAll(process.stderr);
+
+      if (options.stderr) {
+        assertEquals(new TextDecoder().decode(stderr), options.stderr);
+      } else {
+        await Deno.writeAll(Deno.stderr, stderr);
+      }
+
+      process.stderr.close();
+
+      const status = await process.status();
+      assertEquals(status.code, options.exitCode ? +options.exitCode : 0);
+
+      process.close();
+    });
+  }
+}

std/wasi/testdata/std_env_args.rs

@@ -0,0 +1,6 @@
+// { "args": ["one", "two", "three" ]}
+
+fn main() {
+  let args = std::env::args();
+  assert_eq!(args.len(), 3);
+}

std/wasi/testdata/std_env_vars.rs

@@ -0,0 +1,6 @@
+// { "env": { "one": "1", "two": "2", "three": "3" } }
+
+fn main() {
+  let vars = std::env::vars();
+  assert_eq!(vars.count(), 3);
+}

std/wasi/testdata/std_io_stderr.rs

@@ -0,0 +1,7 @@
+// { "stderr": "Hello, stderr!" }
+
+use std::io::Write;
+
+fn main() {
+  assert!(std::io::stderr().write_all(b"Hello, stderr!").is_ok())
+}

std/wasi/testdata/std_io_stdin.rs

@@ -0,0 +1,9 @@
+// { "stdin": "Hello, stdin!" }
+
+use std::io::Read;
+
+fn main() {
+  let mut buffer = String::new();
+  assert!(std::io::stdin().read_to_string(&mut buffer).is_ok());
+  assert_eq!(buffer, "Hello, stdin!")
+}

std/wasi/testdata/std_io_stdout.rs

@@ -0,0 +1,7 @@
+// { "stdout": "Hello, stdout!" }
+
+use std::io::Write;
+
+fn main() {
+  assert!(std::io::stdout().write_all(b"Hello, stdout!").is_ok())
+}

std/wasi/testdata/std_process_exit.rs

@@ -0,0 +1,5 @@
+// { "exitCode": "120" }
+
+fn main() {
+  std::process::exit(120);
+}