feat(endo-exec): new package

Author: michaelfig

package.json

@@ -11,6 +11,7 @@
     "packages/cli",
     "packages/compartment-mapper",
     "packages/daemon",
+    "packages/endo-exec",
     "packages/eslint-config",
     "packages/eslint-plugin",
     "packages/eventual-send",

packages/endo-exec/README.md

@@ -0,0 +1,30 @@
+# Endo Exec
+
+The Endo executor is a helper for creating scripts that are executed in a Hardened JS start compartment.  It opts for compatibility with legacy code when possible.
+
+NOTE: if you want control over how Endo is initialized, especially if you are
+writing an application that needs to use mixed Compartments (both trusted
+libraries and untrusted code), you should NOT use this package.
+
+Use it like:
+
+```js
+#! /usr/bin/env endo-exec
+console.log('Hello, Endo world!');
+```
+
+Or if you want to have your script be importable without side-effects (ocap
+discipline), then avoid top-level module state and export a `main` entrypoint
+that can be executed on demand.
+
+```js
+#! /usr/bin/env endo-exec
+import { promises as fs } from 'fs';
+
+/** @type {import('endo-exec').Main} */ 
+export const main = async ([script, file]) => {
+  console.log('Hello from', script);
+  await fs.readFile(file);
+  console.log(`Here's the file`, file);
+};
+```

packages/endo-exec/bin/endo-exec

@@ -0,0 +1,4 @@
+#! /usr/bin/env bash
+real0=$(readlink -f "${BASH_SOURCE[0]}" || echo "${BASH_SOURCE[0]}")
+thisdir=$(cd "$(dirname -- "$real0")/.." >/dev/null && pwd -P)
+exec node "$thisdir/endo-exec.cjs" ${1+"$@"}

packages/endo-exec/bin/endo-exec.cmd

@@ -0,0 +1 @@
+    @node %~dp0\..\endo-exec.cjs %*

packages/endo-exec/endo-exec.cjs

@@ -0,0 +1,30 @@
+#!/usr/bin/env node
+(async () => {
+  // We use the legacy mode for maximum compatibility.
+  await import('@endo/init/legacy.js');
+
+  // Trim off the Node.js interpreter name.
+  const [_nodeJS, endoExec, script, ...args] = process.argv;
+  assert(script, `Usage: ${endoExec} SCRIPT [ARGS...]`);
+
+  const url = await import('url');
+  const mod = new URL(script, url.pathToFileURL('./')).href;
+
+  // Execute the `main` import if there is one.
+  const { main } = await import(mod);
+  let resultP;
+  if (typeof main === 'function') {
+    resultP = main(harden([script, ...args]));
+  }
+
+  const result = await resultP;
+  if (Number.isSafeInteger(result)) {
+    // Specify an exit code.
+    process.exitCode = result;
+  }
+})().catch(error => {
+  console.error(error);
+  if (process.exitCode === 0) {
+    process.exitCode = 1;
+  }
+});

packages/endo-exec/package.json

@@ -0,0 +1,35 @@
+{
+  "name": "endo-exec",
+  "version": "0.1.0",
+  "description": "Endo script executor",
+  "keywords": [],
+  "author": "Endo contributors",
+  "license": "Apache-2.0",
+  "homepage": "https://github.com/endojs/endo/tree/master/packages/cli#readme",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/endojs/endo.git"
+  },
+  "bugs": {
+    "url": "https://github.com/endojs/endo/issues"
+  },
+  "type": "module",
+  "exports": {
+    "./endo-exec.cjs": "./endo-exec.cjs"
+  },
+  "bin": "./bin/endo-exec",
+  "scripts": {
+    "build": "exit 0",
+    "lint": "exit 0",
+    "lint-fix": "exit 0",
+    "test": "exit 0"
+  },
+  "dependencies": {
+    "@endo/init": "^0.5.42",
+    "global": "^4.4.0"
+  },
+  "devDependencies": {},
+  "publishConfig": {
+    "access": "public"
+  }
+}

packages/endo-exec/scripts/hello.js

@@ -0,0 +1,2 @@
+#! /usr/bin/env endo-exec
+console.log('Hello, Endo world!');

packages/endo-exec/scripts/zx-head.js

@@ -0,0 +1,7 @@
+#! /usr/bin/env endo-exec
+import 'zx/globals';
+
+export const main = async ([script, file]) => {
+  echo`Hello, world (from ${script})!`;
+  await $`head -5 ${file}`;
+};