Use acorn for JS parsing

package.json

@@ -22,12 +22,13 @@
     "temp": "^0.8.3"
   },
   "dependencies": {
+    "acorn": "^6.1.1",
     "ast-util": "^0.6.0",
+    "encoding-down": "~5.0.0",
     "indent-string": "^3.2.0",
     "leveldown": "~4.0.0",
     "levelup": "~3.0.0",
-    "encoding-down": "~5.0.0",
-    "recast": "^0.12.6",
+    "recast": "^0.17.5",
     "resolve": "^1.5.0",
     "source-map": "^0.5.6"
   }

src/file-require-transform.js

@@ -25,7 +25,16 @@ module.exports = class FileRequireTransform {
       // supported inside javascript strings) with escape unicode sequences.
       source = "module.exports = " + source.replace(/\u2028/g, '\\u2028').replace(/\u2029/g, '\\u2029')
     }
-    this.ast = recast.parse(source)
+    this.ast = recast.parse(source, {
+      parser: {
+        parse(source) {
+          return require('recast/parsers/acorn').parse(source, {
+            ecmaVersion: 9,
+            sourceType: 'script'
+          })
+        }
+      }
+    })
     this.lazyRequireFunctionsByVariableName = new Map()
     this.replaceDeferredRequiresWithLazyFunctions()
     this.replaceReferencesToDeferredRequiresWithFunctionCalls()

test/unit/file-require-transform.test.js

@@ -355,6 +355,16 @@ suite('FileRequireTransform', () => {
     )
   })
 
+  test('Object spread properties', () => {
+    const source = 'let {a, b, ...rest} = {a: 1, b: 2, c: 3}'
+    assert.equal(
+      new FileRequireTransform({source, didFindRequire: () => false}).apply(),
+      dedent`
+        let {a, b, ...rest} = {a: 1, b: 2, c: 3}
+      `
+    )
+  })
+
   test('path resolution', () => {
     const baseDirPath = path.resolve(__dirname, '..', 'fixtures', 'module-1')
     const filePath = path.join(baseDirPath, 'dir', 'entry.js')