fix: excise @babel/core except from ui-components

Author: michaelfig

packages/SwingSet/package.json

@@ -50,7 +50,6 @@
     "@agoric/tame-metering": "^1.3.9",
     "@agoric/transform-metering": "^1.4.12",
     "@agoric/xsnap": "^0.6.2",
-    "@babel/core": "^7.5.0",
     "@babel/generator": "^7.6.4",
     "@endo/base64": "^0.1.0",
     "@types/tmp": "^0.2.0",

packages/SwingSet/src/controller.js

@@ -8,7 +8,6 @@ import { performance } from 'perf_hooks';
 import { spawn } from 'child_process';
 import { type as osType } from 'os';
 import { Worker } from 'worker_threads';
-import * as babelCore from '@babel/core';
 import anylogger from 'anylogger';
 import { tmpName } from 'tmp';
 
@@ -213,7 +212,7 @@ export async function makeSwingsetController(
   // cannot be implemented within a non-start-Compartment. We build it out
   // here and pass it to the kernel, which then passes it to vats. This is
   // intended to be powerless.
-  const mt = makeMeteringTransformer(babelCore);
+  const mt = makeMeteringTransformer();
   function transformMetering(src, getMeter) {
     // 'getMeter' provides the meter to which the transformation itself is
     // billed (the COMPUTE meter is charged the length of the source string).

packages/SwingSet/test/metering/test-metering.js

@@ -6,7 +6,6 @@ import { assert, details as X } from '@agoric/assert';
 import bundleSource from '@agoric/bundle-source';
 import { importBundle } from '@agoric/import-bundle';
 import { makeMeter, makeMeteringTransformer } from '@agoric/transform-metering';
-import * as babelCore from '@babel/core';
 import re2 from 're2';
 import test from 'ava';
 import { waitUntilQuiescent } from '../../src/waitUntilQuiescent';
@@ -52,7 +51,7 @@ async function meteredImportBundle(bundle, endowments) {
   // controller into the kernel, so the kernel can create dynamic vats. We can also
   // pass it into static vats, so within-vat metering can happen.
 
-  const mt = makeMeteringTransformer(babelCore);
+  const mt = makeMeteringTransformer();
   function transform(src) {
     const ss = mt.rewrite({ src, endowments: { getMeter } });
     // const newRegExp = ss.endowments.RegExp; // === re2

packages/transform-metering/README.md

@@ -6,52 +6,9 @@ This technique is not airtight, but it is at least is a best approximation in th
 
 ## Quickstart
 
-### SES 1.0
-
-The following example is for legacy [SES-1.0](https://github.com/Agoric/SES#readme):
-
-```js
-import { SES1TameMeteringShim, SES1ReplaceGlobalMeter } from '@agoric/tame-metering';
-import SES1 from 'ses';
-import * as babelCore from '@babel/core';
-import { makeMeteredEvaluator } from '@agoric/transform-metering';
-
-// Create a new SES instance (root realm).
-const sesRealm = SES1.makeSESRootRealm({
-  shims: [SES1TameMeteringShim],
-  configurableGlobals: true,
-});
-
-const replaceGlobalMeter = SES1ReplaceGlobalMeter(sesRealm);
-
-const meteredEval = makeMeteredEvaluator({
-  // Needed for enabling metering of the global builtins.
-  replaceGlobalMeter,
-  // Needed for source transforms that prevent runaways.
-  babelCore,
-  // Create an object with an `evaluate(src, endowments, options)` method
-  makeEvaluator: opts => {
-    const c = sesRealm.global.Realm.makeCompartment(opts);
-    // FIXME: Realms bug doesn't propagate global properties.
-    Object.defineProperties(
-      c.global,
-      Object.getOwnPropertyDescriptors(sesRealm.global),
-    );
-    return c;
-  },
-  // Call a callback when the code inside the meteredEval is done evaluating.
-  quiesceCallback: cb => setTimeout(cb),
-});
-```
-
-### SES 2.0
-
-This example is for the [SES 2.0 (beta)](https://github.com/Agoric/SES-beta#readme).  Note that it currently has issues that prevents it from working correctly, but YMMV.
-
 ```js
 import { tameMetering } from '@agoric/tame-metering';
 import { lockdown } from 'ses';
-import * as babelCore from '@babel/core';
 import { makeMeteredEvaluator } from '@agoric/transform-metering';
 
 // Override all the global objects with metered versions.
@@ -63,8 +20,6 @@ lockdown();
 const meteredEval = makeMeteredEvaluator({
   // Needed for enabling metering of the global builtins.
   replaceGlobalMeter,
-  // Needed for source transforms that prevent runaways.
-  babelCore,
   // Create an object with an `evaluate(src, endowments)` method
   makeEvaluator: opts => {
     const c = new Compartment(undefined, undefined, opts);

packages/transform-metering/package.json

@@ -16,7 +16,6 @@
   },
   "devDependencies": {
     "@agoric/install-ses": "^0.5.13",
-    "@babel/core": "^7.5.0",
     "ava": "^3.12.1",
     "esm": "^3.2.5",
     "nyc": "^15.1.0",
@@ -26,6 +25,10 @@
   "dependencies": {
     "@agoric/nat": "^4.0.0",
     "@agoric/tame-metering": "^1.3.9",
+    "@agoric/babel-parser": "^7.6.4",
+    "@babel/types": "^7.6.0",
+    "@babel/generator": "^7.6.0",
+    "@babel/traverse": "^7.6.0",
     "re2": "^1.10.5"
   },
   "keywords": [],

packages/transform-metering/src/pure-babel-core.js

@@ -0,0 +1,60 @@
+import * as babelParser from '@agoric/babel-parser';
+import traverse, { NodePath } from '@babel/traverse';
+import generator from '@babel/generator';
+import * as types from '@babel/types';
+
+// Create a file structure to wire into @babel/traverse.
+export function makePureFile({ code, ast }) {
+  const file = {
+    ast,
+    opts: {},
+    code,
+  };
+  file.hub = {
+    file,
+    getCode: () => file.code,
+    getScope: () => file.scope,
+    addHelper() {
+      throw Error(`Helpers are not supported by the fake file hub.`);
+    },
+    buildError(_node, msg, Error = TypeError) {
+      return new Error(msg);
+    },
+  };
+  file.path = NodePath.get({
+    hub: file.hub,
+    parentPath: null,
+    parent: file.ast,
+    container: file.ast,
+    key: 'program',
+  }).setContext();
+  file.scope = file.path.scope;
+  return file;
+}
+
+/**
+ * Create a working subset of babelCore that doesn't touch the filesystem.
+ */
+export function makePureBabelCore() {
+  return {
+    parseSync(source, { parserOpts = undefined } = {}) {
+      return babelParser.parse(source, parserOpts);
+    },
+    transformFromAstSync(ast, code = undefined, transformOptions = undefined) {
+      const { generatorOpts, plugins } = transformOptions || {};
+
+      const pluginArgs = [{ types }];
+      const visitors = plugins
+        .map(p => p(...pluginArgs).visitor)
+        .filter(v => v);
+      if (!visitors.length) {
+        // We fail here because a null transform is unnecessary.
+        throw Error(`No visitors found in plugins`);
+      }
+      const visitor = traverse.visitors.merge(visitors);
+      const file = makePureFile({ ast, code });
+      traverse(file.ast, visitor);
+      return generator(ast, generatorOpts, code);
+    },
+  };
+}

packages/transform-metering/src/transform.js

@@ -1,5 +1,6 @@
 /* global require */
 import * as c from './constants';
+import { makePureBabelCore } from './pure-babel-core';
 
 // We'd like to import this, but RE2 is cjs
 const RE2 = require('re2');
@@ -8,7 +9,7 @@ const METER_GENERATED = Symbol('meter-generated');
 const getMeterId = 'getMeter';
 
 export function makeMeteringTransformer(
-  babelCore,
+  babelCore = makePureBabelCore(),
   {
     overrideParser = undefined,
     overrideRegExp = RE2,
@@ -192,7 +193,6 @@ const ${reid}=RegExp(${JSON.stringify(pattern)},${JSON.stringify(flags)});`);
           compact: false,
         },
         plugins: [meteringPlugin(regexpList)],
-        ast: true,
         code: true,
       });
 

packages/transform-metering/test/test-transform.js

@@ -1,15 +1,14 @@
 /* global __dirname */
 /* eslint-disable no-await-in-loop */
 import test from 'ava';
-import * as babelCore from '@babel/core';
 import fs from 'fs';
 
 import { makeMeteringTransformer } from '../src/index';
 import * as c from '../src/constants';
 
 test('meter transform', async t => {
   let getMeter;
-  const meteringTransform = makeMeteringTransformer(babelCore, {
+  const meteringTransform = makeMeteringTransformer(undefined, {
     overrideMeterId: '$m',
     overrideRegExpIdPrefix: '$re_',
   });

packages/transform-metering/test/test-zzz-eval.js

@@ -1,10 +1,9 @@
 /* global process setTimeout */
-// eslint-disable-next-line import/order
 import { replaceGlobalMeter } from './install-metering';
 import '@agoric/install-ses'; // calls lockdown()
 
+// eslint-disable-next-line import/order
 import test from 'ava';
-import * as babelCore from '@babel/core';
 
 import { makeMeter, makeMeteredEvaluator } from '../src/index';
 
@@ -42,7 +41,6 @@ test.skip('metering evaluator', async t => {
           refiller();
         }
       },
-      babelCore,
       makeEvaluator,
       quiesceCallback: cb => setTimeout(cb),
     });