feat: Preserve formatting

.gitignore

@@ -74,3 +74,5 @@ dist/
 api-docs
 
 .aider*
+
+vendor

package.json

@@ -53,7 +53,15 @@
     "atLeast": 0
   },
   "resolutions": {
-    "@babel/types": "7.24.0",
+    "@babel/code-frame": "./vendor/@babel/code-frame/code-frame-7.25.7.tgz",
+    "@babel/generator": "./vendor/@babel/generator/generator-7.25.7.tgz",
+    "@babel/parser": "./vendor/@babel/parser/parser-7.25.7.tgz",
+    "@babel/template": "./vendor/@babel/template/template-7.25.7.tgz",
+    "@babel/highlight": "./vendor/@babel/highlight/highlight-7.25.7.tgz",
+    "@babel/helper-string-parser": "./vendor/@babel/helper-string-parser/helper-string-parser-7.25.7.tgz",
+    "@babel/helper-validator-identifier": "./vendor/@babel/helper-validator-identifier/helper-validator-identifier-7.25.7.tgz",
+    "@babel/traverse": "./vendor/@babel/traverse/traverse-7.25.7.tgz",
+    "@babel/types": "./vendor/@babel/types/types-7.25.7.tgz",
     "@lerna/version@npm:5.6.2": "patch:@lerna/version@npm%3A5.6.2#~/.yarn/patches/@lerna-version-npm-5.6.2-ce2d9cb2f5.patch",
     "@lerna/conventional-commits@npm:5.6.2": "patch:@lerna/conventional-commits@npm%3A5.6.2#~/.yarn/patches/@lerna-conventional-commits-npm-5.6.2-a373ba4bc0.patch"
   }

packages/evasive-transform/package.json

@@ -75,7 +75,7 @@
     "timeout": "2m"
   },
   "dependencies": {
-    "@agoric/babel-generator": "^7.17.6",
+    "@babel/generator": "^7.17.6",
     "@babel/parser": "^7.23.6",
     "@babel/traverse": "^7.23.6",
     "source-map-js": "^1.2.0"

packages/evasive-transform/src/generate.js

@@ -4,7 +4,7 @@
  * @module
  */
 
-import babelGenerator from '@agoric/babel-generator';
+import babelGenerator from '@babel/generator';
 
 // TODO The following is sufficient on Node.js, but for compatibility with
 // `node -r esm`, we must use the pattern below.
@@ -66,12 +66,17 @@ export const generate =
       // TODO Use options?.sourceUrl when resolved:
       // https://github.com/Agoric/agoric-sdk/issues/8671
       const sourceUrl = options ? options.sourceUrl : undefined;
-      const result = generator(ast, {
-        sourceFileName: sourceUrl,
-        sourceMaps: Boolean(sourceUrl),
-        retainLines: true,
-        compact: true,
-      });
+      const source = options ? options.source : undefined;
+      const result = generator(
+        ast,
+        {
+          sourceFileName: sourceUrl,
+          sourceMaps: Boolean(sourceUrl),
+          retainLines: true,
+          preserveFormat: true,
+        },
+        source,
+      );
 
       if (sourceUrl) {
         return {

packages/evasive-transform/src/index.js

@@ -72,7 +72,7 @@ export function evadeCensorSync(source, options) {
   if (sourceUrl) {
     return generate(ast, { sourceUrl });
   }
-  return generate(ast);
+  return generate(ast, { source });
 }
 
 /**

packages/evasive-transform/src/parse-ast.js

@@ -33,7 +33,11 @@ const { parse: parseBabel } = babelParser;
  * @param {ParseAstOptions} [opts] - Options for underlying parser
  * @internal
  */
-export function parseAst(source, opts) {
+export function parseAst(source, opts = {}) {
   // Might not want to pass `opts` verbatim, but also might not matter!
-  return parseBabel(source, opts);
+  return parseBabel(source, {
+    tokens: true,
+    createParenthesizedExpression: true,
+    ...opts,
+  });
 }

packages/module-source/package.json

@@ -37,7 +37,7 @@
     "test": "ava"
   },
   "dependencies": {
-    "@agoric/babel-generator": "^7.17.6",
+    "@babel/generator": "^7.17.6",
     "@babel/parser": "^7.23.6",
     "@babel/traverse": "^7.23.6",
     "@babel/types": "^7.24.0",

packages/module-source/src/transform-analyze.js

@@ -1,6 +1,6 @@
 // @ts-nocheck XXX Babel types
-import { makeTransformSource } from './transformSource.js';
-import makeModulePlugins from './babelPlugin.js';
+import { makeTransformSource } from './transform-source.js';
+import makeModulePlugins from './babel-plugin.js';
 
 import * as h from './hidden.js';
 
@@ -71,7 +71,7 @@ const makeCreateStaticRecord = transformSource =>
       .map(
         src =>
           `[${js(src)}, [${Object.entries(isrc[src])
-            .map(([exp, upds]) => `[${js(exp)}, [${upds.join(',')}]]`)
+            .map(([exp, upds]) => `[${js(exp)},[${upds.join(',')}]]`)
             .join(',')}]]`,
       )
       .join(',')}]);`;
@@ -80,9 +80,7 @@ const makeCreateStaticRecord = transformSource =>
         let src = '';
         if (cvname) {
           // It's a function assigned to, so set its name property.
-          src = `Object.defineProperty(${cvname}, 'name', {value: ${js(
-            vname,
-          )}});`;
+          src = `Object.defineProperty(${cvname},'name',{value:${js(vname)}});`;
         }
         const hDeclId = isOnce ? h.HIDDEN_ONCE : h.HIDDEN_LIVE;
         src += `${hDeclId}.${vname}(${cvname || ''});`;
@@ -99,14 +97,9 @@ const makeCreateStaticRecord = transformSource =>
     // well.
     // Relies on the evaluator to ensure these functions are strict.
     let functorSource = `\
-({ \
-  imports: ${h.HIDDEN_IMPORTS}, \
-  liveVar: ${h.HIDDEN_LIVE}, \
-  onceVar: ${h.HIDDEN_ONCE}, \
-  importMeta: ${h.HIDDEN_META}, \
-}) => (function () { 'use strict'; \
-  ${preamble} \
-  ${scriptSource}
+({imports:${h.HIDDEN_IMPORTS},liveVar:${h.HIDDEN_LIVE},onceVar:${h.HIDDEN_ONCE},importMeta:${h.HIDDEN_META}})=>(function(){'use strict';\
+${preamble}\
+${scriptSource}
 })()
 `;
 

packages/module-source/src/transformSource.js → packages/module-source/src/transform-source.js

@@ -1,6 +1,6 @@
 // @ts-nocheck XXX Babel types
 import * as babelParser from '@babel/parser';
-import babelGenerate from '@agoric/babel-generator';
+import babelGenerate from '@babel/generator';
 import babelTraverse from '@babel/traverse';
 import * as babelTypes from '@babel/types';
 
@@ -26,22 +26,30 @@ export const makeTransformSource = (makeModulePlugins, babel = null) => {
     const { sourceUrl, sourceMapUrl, sourceType, sourceMap, sourceMapHook } =
       sourceOptions;
 
-    const ast = parseBabel(source, { sourceType });
+    const ast = parseBabel(source, {
+      sourceType,
+      tokens: true,
+      createParenthesizedExpression: true,
+    });
 
     traverseBabel(ast, visitorFromPlugin(analyzePlugin));
     traverseBabel(ast, visitorFromPlugin(transformPlugin));
 
     const sourceMaps = sourceOptions.sourceMapHook !== undefined;
 
     const { code: transformedSource, map: transformedSourceMap } =
-      generateBabel(ast, {
-        sourceFileName: sourceMapUrl,
-        sourceMaps,
-        inputSourceMap: sourceMap,
-        retainLines: true,
-        compact: true,
-        verbatim: true,
-      });
+      generateBabel(
+        ast,
+        {
+          sourceFileName: sourceMapUrl,
+          sourceMaps,
+          inputSourceMap: sourceMap,
+          retainLines: true,
+          preserveFormat: true,
+          verbatim: true,
+        },
+        source,
+      );
 
     if (sourceMaps) {
       sourceMapHook(transformedSourceMap, {

packages/module-source/test/benchmark-babel-plugin.js

@@ -1,8 +1,8 @@
 import Benchmark from 'benchmark';
 import fs from 'fs';
 import url from 'url';
-import { makeTransformSource } from '../src/transformSource.js';
-import makeModulePlugins from '../src/babelPlugin.js';
+import { makeTransformSource } from '../src/transform-source.js';
+import makeModulePlugins from '../src/babel-plugin.js';
 
 const suite = new Benchmark.Suite();
 

packages/module-source/test/fixtures/format-preserved.txt

@@ -0,0 +1,11 @@
+({imports:$h͏_imports,liveVar:$h͏_live,onceVar:$h͏_once,importMeta:$h͏____meta})=>(function(){'use strict';$h͏_imports([]);Object.defineProperty(createBinop,'name',{value:"createBinop"});$h͏_once.createBinop(createBinop);// deliberately offset
+function TokenType() {}
+const beforeExpr = 0;
+
+       function createBinop(name, binop) {
+  return new TokenType(name, {
+    beforeExpr,
+    binop,
+  });
+}
+})()

packages/module-source/test/fixtures/preserve-format.js

@@ -0,0 +1,10 @@
+// deliberately offset
+function TokenType() {}
+const beforeExpr = 0;
+
+export function createBinop(name, binop) {
+  return new TokenType(name, {
+    beforeExpr,
+    binop,
+  });
+}

packages/module-source/test/preserve-format.js

@@ -0,0 +1,16 @@
+import url from 'url';
+import fs from 'fs';
+import { ModuleSource } from '../src/module-source.js';
+import './lockdown.js';
+
+function readFixture(filename) {
+  return fs.readFileSync(
+    url.fileURLToPath(new URL(filename, import.meta.url)),
+    'utf-8',
+  );
+}
+
+const { __syncModuleProgram__ } = new ModuleSource(
+  readFixture('fixtures/preserve-format.js'),
+);
+console.error(__syncModuleProgram__);

packages/module-source/test/preserve-format.test.js

@@ -0,0 +1,20 @@
+import url from 'url';
+import fs from 'fs';
+import test from 'ava';
+import { ModuleSource } from '../src/module-source.js';
+import './lockdown.js';
+
+function readFixture(filename) {
+  return fs.readFileSync(
+    url.fileURLToPath(new URL(filename, import.meta.url)),
+    'utf-8',
+  );
+}
+
+test('preserves formatting', t => {
+  const { __syncModuleProgram__: actual } = new ModuleSource(
+    readFixture('fixtures/preserve-format.js'),
+  );
+  const expected = readFixture('fixtures/format-preserved.txt');
+  t.is(actual, expected);
+});