Revert baseVisitor change

Author: neoncube2

acorn-walk/src/index.js

@@ -17,6 +17,7 @@
 // state.
 
 export function simple(node, visitors, baseVisitor, state, override) {
+  if (!baseVisitor) baseVisitor = base
   ;(function c(node, st, override) {
     let type = override || node.type
     visitNode(baseVisitor, type, node, st, c)
@@ -29,6 +30,7 @@ export function simple(node, visitors, baseVisitor, state, override) {
 // (and also as state parameter when no other state is present).
 export function ancestor(node, visitors, baseVisitor, state, override) {
   let ancestors = []
+  if (!baseVisitor) baseVisitor = base
   ;(function c(node, st, override) {
     let type = override || node.type
     let isNew = node !== ancestors[ancestors.length - 1]
@@ -66,6 +68,7 @@ class Found {
 
 // A full walk triggers the callback on each node
 export function full(node, callback, baseVisitor, state, override) {
+  if (!baseVisitor) baseVisitor = base
   let last
   ;(function c(node, st, override) {
     let type = override || node.type
@@ -80,6 +83,7 @@ export function full(node, callback, baseVisitor, state, override) {
 // An fullAncestor walk is like an ancestor walk, but triggers
 // the callback on each node
 export function fullAncestor(node, callback, baseVisitor, state) {
+  if (!baseVisitor) baseVisitor = base
   let ancestors = [], last
   ;(function c(node, st, override) {
     let type = override || node.type
@@ -98,6 +102,7 @@ export function fullAncestor(node, callback, baseVisitor, state) {
 // null can be used as wildcard). Returns a {node, state} object, or
 // undefined when it doesn't find a matching node.
 export function findNodeAt(node, start, end, test, baseVisitor, state) {
+  if (!baseVisitor) baseVisitor = base
   test = makeTest(test)
   try {
     (function c(node, st, override) {
@@ -120,6 +125,7 @@ export function findNodeAt(node, start, end, test, baseVisitor, state) {
 // position. Interface similar to findNodeAt.
 export function findNodeAround(node, pos, test, baseVisitor, state) {
   test = makeTest(test)
+  if (!baseVisitor) baseVisitor = base
   try {
     (function c(node, st, override) {
       let type = override || node.type
@@ -136,6 +142,7 @@ export function findNodeAround(node, pos, test, baseVisitor, state) {
 // Find the outermost matching node after a given position.
 export function findNodeAfter(node, pos, test, baseVisitor, state) {
   test = makeTest(test)
+  if (!baseVisitor) baseVisitor = base
   try {
     (function c(node, st, override) {
       if (node.end < pos) return
@@ -152,6 +159,7 @@ export function findNodeAfter(node, pos, test, baseVisitor, state) {
 // Find the outermost matching node before a given position.
 export function findNodeBefore(node, pos, test, baseVisitor, state) {
   test = makeTest(test)
+  if (!baseVisitor) baseVisitor = base
   let max
   ;(function c(node, st, override) {
     if (node.start > pos) return
@@ -175,7 +183,6 @@ function skipThrough(node, st, c) { c(node, st) }
 function ignore(_node, _st, _c) { }
 
 function visitNode(baseVisitor, type, node, st, c) {
-  if (!baseVisitor) baseVisitor = base
   if (baseVisitor[type] == null) throw `Unregistered node type ${type}`
   baseVisitor[type](node, st, c)
 }