refactor(compiler): switch to acorn

packages/compiler-core/__tests__/transforms/transformExpressions.spec.ts

@@ -345,6 +345,6 @@ describe('compiler: expression transform', () => {
   test('should handle parse error', () => {
     const onError = jest.fn()
     parseWithExpressionTransform(`{{ a( }}`, { onError })
-    expect(onError.mock.calls[0][0].message).toMatch(`Expected ')'`)
+    expect(onError.mock.calls[0][0].message).toMatch(`Unexpected token (1:4)`)
   })
 })

packages/compiler-core/package.json

@@ -28,8 +28,8 @@
   },
   "homepage": "https://github.com/vuejs/vue/tree/dev/packages/compiler-core#readme",
   "dependencies": {
+    "acorn": "^7.1.0",
     "estree-walker": "^0.8.1",
-    "meriyah": "^1.7.2",
     "source-map": "^0.7.3"
   }
 }

packages/compiler-core/src/utils.ts

@@ -1,19 +1,19 @@
 import { SourceLocation, Position, ElementNode, NodeTypes } from './ast'
-import { parseScript } from 'meriyah'
+import { parse } from 'acorn'
 import { walk } from 'estree-walker'
 
 // cache node requires
 // lazy require dependencies so that they don't end up in rollup's dep graph
 // and thus can be tree-shaken in browser builds.
-let _parseScript: typeof parseScript
+let _parse: typeof parse
 let _walk: typeof walk
 
-export const parseJS: typeof parseScript = (code: string, options: any) => {
+export const parseJS: typeof parse = (code: string, options: any) => {
   assert(
     !__BROWSER__,
     `Expression AST analysis can only be performed in non-browser builds.`
   )
-  const parse = _parseScript || (_parseScript = require('meriyah').parseScript)
+  const parse = _parse || (_parse = require('acorn').parse)
   return parse(code, options)
 }