forked from babel/babel
/
index.js
108 lines (85 loc) · 2.63 KB
/
index.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
/* eslint max-len: 0 */
import TraversalContext from "./context";
import * as visitors from "./visitors";
import * as messages from "babel-messages";
import includes from "lodash/includes";
import * as t from "babel-types";
import * as cache from "./cache";
export { default as NodePath } from "./path";
export { default as Scope } from "./scope";
import type Hub from "./hub";
export type { Hub };
export { visitors };
export default function traverse(
parent: Object | Array<Object>,
opts?: Object,
scope?: Object,
state: Object,
parentPath: Object,
) {
if (!parent) return;
if (!opts) opts = {};
if (!opts.noScope && !scope) {
if (parent.type !== "Program" && parent.type !== "File") {
throw new Error(messages.get("traverseNeedsParent", parent.type));
}
}
visitors.explode(opts);
traverse.node(parent, opts, scope, state, parentPath);
}
traverse.visitors = visitors;
traverse.verify = visitors.verify;
traverse.explode = visitors.explode;
traverse.NodePath = require("./path");
traverse.Scope = require("./scope");
traverse.cheap = function (node, enter) {
return t.traverseFast(node, enter);
};
traverse.node = function (node: Object, opts: Object, scope: Object, state: Object, parentPath: Object, skipKeys?) {
let keys: Array = t.VISITOR_KEYS[node.type];
if (!keys) return;
let context = new TraversalContext(scope, opts, state, parentPath);
for (let key of keys) {
if (skipKeys && skipKeys[key]) continue;
if (context.visit(node, key)) return;
}
};
traverse.clearNode = function (node, opts) {
t.removeProperties(node, opts);
cache.path.delete(node);
};
traverse.removeProperties = function (tree, opts) {
t.traverseFast(tree, traverse.clearNode, opts);
return tree;
};
function hasBlacklistedType(path, state) {
if (path.node.type === state.type) {
state.has = true;
path.stop();
}
}
traverse.hasType = function (tree: Object, scope: Object, type: Object, blacklistTypes: Array<string>): boolean {
// the node we're searching in is blacklisted
if (includes(blacklistTypes, tree.type)) return false;
// the type we're looking for is the same as the passed node
if (tree.type === type) return true;
let state = {
has: false,
type: type
};
traverse(tree, {
blacklist: blacklistTypes,
enter: hasBlacklistedType
}, scope, state);
return state.has;
};
traverse.clearCache = function() {
cache.clear();
};
traverse.clearCache.clearPath = cache.clearPath;
traverse.clearCache.clearScope = cache.clearScope;
traverse.copyCache = function(source, destination) {
if (cache.path.has(source)) {
cache.path.set(destination, cache.path.get(source));
}
};