94 lines
2.2 KiB
JavaScript
94 lines
2.2 KiB
JavaScript
var VISITOR_KEYS = require("./visitor-keys");
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var _ = require("lodash");
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var traverse = module.exports = function (parent, callbacks, blacklistTypes) {
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if (!parent) return;
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if (_.isArray(parent)) {
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_.each(parent, function (node) {
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traverse(node, callbacks, blacklistTypes);
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});
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return;
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}
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var keys = VISITOR_KEYS[parent.type];
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if (!keys) return;
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blacklistTypes = blacklistTypes || [];
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if (_.isFunction(callbacks)) {
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callbacks = { enter: callbacks };
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}
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_.each(keys, function (key) {
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var nodes = parent[key];
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if (!nodes) return;
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var handle = function (obj, key) {
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var node = obj[key];
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if (!node) return;
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// type is blacklisted
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if (blacklistTypes.indexOf(node.type) >= 0) return;
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// enter
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var result = callbacks.enter(node, parent, obj, key);
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// stop iteration
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if (result === false) return;
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// replace node
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if (result != null) node = obj[key] = result;
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traverse(node, callbacks, blacklistTypes);
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// exit
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if (callbacks.exit) callbacks.exit(node, parent, obj, key);
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};
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if (_.isArray(nodes)) {
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_.each(nodes, function (node, i) {
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handle(nodes, i);
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});
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// remove deleted nodes
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parent[key] = _.flatten(parent[key]).filter(function (node) {
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return node !== traverse.Delete;
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});
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} else {
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handle(parent, key);
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if (parent[key] === traverse.Delete) {
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throw new Error("trying to delete property " + key + " from " +
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parent.type + " but can't because it's required");
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}
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}
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});
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};
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traverse.FUNCTION_TYPES = ["ArrowFunctionExpression", "FunctionDeclaration", "FunctionExpression"];
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traverse.Delete = {};
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traverse.hasType = function (tree, type, blacklistTypes) {
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if (tree.type === type) return true;
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var has = false;
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blacklistTypes = blacklistTypes || [];
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if (_.isArray(tree)) {
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return !!_.find(tree, function (node) {
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return traverse.hasType(node, type, blacklistTypes);
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});
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} else {
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traverse(tree, function (node) {
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if (node.type === type) {
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has = true;
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return false;
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}
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}, blacklistTypes);
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}
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return has;
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};
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