1 files changed, 51 insertions, 0 deletions
diff --git a/node_modules/estree-walker/src/estree-walker.js b/node_modules/estree-walker/src/estree-walker.js
new file mode 100644
index 0000000..6ecd498
--- /dev/null
+++ b/node_modules/estree-walker/src/estree-walker.js
@@ -0,0 +1,51 @@
+export function walk(ast, { enter, leave }) {
+	visit(ast, null, enter, leave);
+}
+
+let shouldSkip = false;
+const context = { skip: () => shouldSkip = true };
+
+export const childKeys = {};
+
+const toString = Object.prototype.toString;
+
+function isArray(thing) {
+	return toString.call(thing) === '[object Array]';
+}
+
+function visit(node, parent, enter, leave, prop, index) {
+	if (!node) return;
+
+	if (enter) {
+		const _shouldSkip = shouldSkip;
+		shouldSkip = false;
+		enter.call(context, node, parent, prop, index);
+		const skipped = shouldSkip;
+		shouldSkip = _shouldSkip;
+
+		if (skipped) return;
+	}
+
+	const keys = node.type && childKeys[node.type] || (
+		childKeys[node.type] = Object.keys(node).filter(key => typeof node[key] === 'object')
+	);
+
+	for (let i = 0; i < keys.length; i += 1) {
+		const key = keys[i];
+		const value = node[key];
+
+		if (isArray(value)) {
+			for (let j = 0; j < value.length; j += 1) {
+				value[j] && value[j].type && visit(value[j], node, enter, leave, key, j);
+			}
+		}
+
+		else if (value && value.type) {
+			visit(value, node, enter, leave, key, null);
+		}
+	}
+
+	if (leave) {
+		leave(node, parent, prop, index);
+	}
+}