Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly
Appearance settings

Commit 0bca959

Browse filesBrowse files
jasnellFishrock123
jasnell
authored and
Fishrock123
committed
util: fix inspecting of proxy objects
In certain conditions, inspecting a Proxy object can lead to a max call stack error. Avoid that by detecting the Proxy object and outputting information about the Proxy object itself. Fixes: #6464 PR-URL: #6465 Reviewed-By: Myles Borins <myles.borins@gmail.com> Reviewed-By: Colin Ihrig <cjihrig@gmail.com> Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
1 parent d674493 commit 0bca959
Copy full SHA for 0bca959

File tree

Expand file treeCollapse file tree

5 files changed

+189
-1
lines changed
Open diff view settings
Filter options
Expand file treeCollapse file tree

5 files changed

+189
-1
lines changed
Open diff view settings
Collapse file

‎benchmark/util/inspect-proxy.js‎

Copy file name to clipboard
+44Lines changed: 44 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,44 @@
1+
'use strict';
2+
3+
const util = require('util');
4+
const common = require('../common.js');
5+
6+
const bench = common.createBenchmark(main, {
7+
v: [1, 2],
8+
n: [1e6]
9+
});
10+
11+
function twoDifferentProxies(n) {
12+
// This one should be slower between we're looking up multiple proxies.
13+
const proxyA = new Proxy({}, {get: () => {}});
14+
const proxyB = new Proxy({}, {get: () => {}});
15+
bench.start();
16+
for (var i = 0; i < n; i += 1)
17+
util.inspect({a: proxyA, b: proxyB}, {showProxy: true});
18+
bench.end(n);
19+
}
20+
21+
function oneProxy(n) {
22+
// This one should be a bit faster because of the internal caching.
23+
const proxy = new Proxy({}, {get: () => {}});
24+
bench.start();
25+
for (var i = 0; i < n; i += 1)
26+
util.inspect({a: proxy, b: proxy}, {showProxy: true});
27+
bench.end(n);
28+
}
29+
30+
function main(conf) {
31+
const n = conf.n | 0;
32+
const v = conf.v | 0;
33+
34+
switch (v) {
35+
case 1:
36+
oneProxy(n);
37+
break;
38+
case 2:
39+
twoDifferentProxies(n);
40+
break;
41+
default:
42+
throw new Error('Should not get to here');
43+
}
44+
}
Collapse file

‎doc/api/util.md‎

Copy file name to clipboardExpand all lines: doc/api/util.md
+4Lines changed: 4 additions & 0 deletions
  • Display the source diff
  • Display the rich diff
Original file line numberDiff line numberDiff line change
@@ -179,6 +179,10 @@ formatted string:
179179
- `customInspect` - if `false`, then custom `inspect(depth, opts)` functions
180180
defined on the objects being inspected won't be called. Defaults to `true`.
181181

182+
- `showProxy` - if `true`, then objects and functions that are Proxy objects
183+
will be introspected to show their `target` and `hander` objects. Defaults to
184+
`false`.
185+
182186
Example of inspecting all properties of the `util` object:
183187

184188
```js
Collapse file

‎lib/util.js‎

Copy file name to clipboardExpand all lines: lib/util.js
+41-1Lines changed: 41 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -139,6 +139,7 @@ function inspect(obj, opts) {
139139
if (ctx.depth === undefined) ctx.depth = 2;
140140
if (ctx.colors === undefined) ctx.colors = false;
141141
if (ctx.customInspect === undefined) ctx.customInspect = true;
142+
if (ctx.showProxy === undefined) ctx.showProxy = false;
142143
if (ctx.colors) ctx.stylize = stylizeWithColor;
143144
return formatValue(ctx, obj, ctx.depth);
144145
}
@@ -241,6 +242,46 @@ function inspectPromise(p) {
241242

242243

243244
function formatValue(ctx, value, recurseTimes) {
245+
if (ctx.showProxy &&
246+
((typeof value === 'object' && value !== null) ||
247+
typeof value === 'function')) {
248+
var proxy = undefined;
249+
var proxyCache = ctx.proxyCache;
250+
if (!proxyCache)
251+
proxyCache = ctx.proxyCache = new Map();
252+
// Determine if we've already seen this object and have
253+
// determined that it either is or is not a proxy.
254+
if (proxyCache.has(value)) {
255+
// We've seen it, if the value is not undefined, it's a Proxy.
256+
proxy = proxyCache.get(value);
257+
} else {
258+
// Haven't seen it. Need to check.
259+
// If it's not a Proxy, this will return undefined.
260+
// Otherwise, it'll return an array. The first item
261+
// is the target, the second item is the handler.
262+
// We ignore (and do not return) the Proxy isRevoked property.
263+
proxy = binding.getProxyDetails(value);
264+
if (proxy) {
265+
// We know for a fact that this isn't a Proxy.
266+
// Mark it as having already been evaluated.
267+
// We do this because this object is passed
268+
// recursively to formatValue below in order
269+
// for it to get proper formatting, and because
270+
// the target and handle objects also might be
271+
// proxies... it's unfortunate but necessary.
272+
proxyCache.set(proxy, undefined);
273+
}
274+
// If the object is not a Proxy, then this stores undefined.
275+
// This tells the code above that we've already checked and
276+
// ruled it out. If the object is a proxy, this caches the
277+
// results of the getProxyDetails call.
278+
proxyCache.set(value, proxy);
279+
}
280+
if (proxy) {
281+
return 'Proxy ' + formatValue(ctx, proxy, recurseTimes);
282+
}
283+
}
284+
244285
// Provide a hook for user-specified inspect functions.
245286
// Check that value is an object with an inspect function on it
246287
if (ctx.customInspect &&
@@ -785,7 +826,6 @@ exports.isPrimitive = isPrimitive;
785826

786827
exports.isBuffer = Buffer.isBuffer;
787828

788-
789829
function pad(n) {
790830
return n < 10 ? '0' + n.toString(10) : n.toString(10);
791831
}
Collapse file

‎src/node_util.cc‎

Copy file name to clipboardExpand all lines: src/node_util.cc
+16Lines changed: 16 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -6,11 +6,13 @@
66
namespace node {
77
namespace util {
88

9+
using v8::Array;
910
using v8::Context;
1011
using v8::FunctionCallbackInfo;
1112
using v8::Local;
1213
using v8::Object;
1314
using v8::Private;
15+
using v8::Proxy;
1416
using v8::String;
1517
using v8::Value;
1618

@@ -37,6 +39,19 @@ using v8::Value;
3739
VALUE_METHOD_MAP(V)
3840
#undef V
3941

42+
static void GetProxyDetails(const FunctionCallbackInfo<Value>& args) {
43+
// Return undefined if it's not a proxy.
44+
if (!args[0]->IsProxy())
45+
return;
46+
47+
Local<Proxy> proxy = args[0].As<Proxy>();
48+
49+
Local<Array> ret = Array::New(args.GetIsolate(), 2);
50+
ret->Set(0, proxy->GetTarget());
51+
ret->Set(1, proxy->GetHandler());
52+
53+
args.GetReturnValue().Set(ret);
54+
}
4055

4156
static void GetHiddenValue(const FunctionCallbackInfo<Value>& args) {
4257
Environment* env = Environment::GetCurrent(args);
@@ -84,6 +99,7 @@ void Initialize(Local<Object> target,
8499

85100
env->SetMethod(target, "getHiddenValue", GetHiddenValue);
86101
env->SetMethod(target, "setHiddenValue", SetHiddenValue);
102+
env->SetMethod(target, "getProxyDetails", GetProxyDetails);
87103
}
88104

89105
} // namespace util
Collapse file

‎test/parallel/test-util-inspect-proxy.js‎

Copy file name to clipboard
+84Lines changed: 84 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,84 @@
1+
'use strict';
2+
3+
require('../common');
4+
const assert = require('assert');
5+
const util = require('util');
6+
const processUtil = process.binding('util');
7+
const opts = {showProxy: true};
8+
9+
const target = {};
10+
const handler = {
11+
get: function() { throw new Error('Getter should not be called'); }
12+
};
13+
const proxyObj = new Proxy(target, handler);
14+
15+
// Inspecting the proxy should not actually walk it's properties
16+
assert.doesNotThrow(() => util.inspect(proxyObj, opts));
17+
18+
// getProxyDetails is an internal method, not intended for public use.
19+
// This is here to test that the internals are working correctly.
20+
const details = processUtil.getProxyDetails(proxyObj);
21+
assert.strictEqual(target, details[0]);
22+
assert.strictEqual(handler, details[1]);
23+
24+
assert.strictEqual(util.inspect(proxyObj, opts),
25+
'Proxy [ {}, { get: [Function] } ]');
26+
27+
// Using getProxyDetails with non-proxy returns undefined
28+
assert.strictEqual(processUtil.getProxyDetails({}), undefined);
29+
30+
// This will throw because the showProxy option is not used
31+
// and the get function on the handler object defined above
32+
// is actually invoked.
33+
assert.throws(
34+
() => util.inspect(proxyObj)
35+
);
36+
37+
// Yo dawg, I heard you liked Proxy so I put a Proxy
38+
// inside your Proxy that proxies your Proxy's Proxy.
39+
const proxy1 = new Proxy({}, {});
40+
const proxy2 = new Proxy(proxy1, {});
41+
const proxy3 = new Proxy(proxy2, proxy1);
42+
const proxy4 = new Proxy(proxy1, proxy2);
43+
const proxy5 = new Proxy(proxy3, proxy4);
44+
const proxy6 = new Proxy(proxy5, proxy5);
45+
const expected0 = '{}';
46+
const expected1 = 'Proxy [ {}, {} ]';
47+
const expected2 = 'Proxy [ Proxy [ {}, {} ], {} ]';
48+
const expected3 = 'Proxy [ Proxy [ Proxy [ {}, {} ], {} ], Proxy [ {}, {} ] ]';
49+
const expected4 = 'Proxy [ Proxy [ {}, {} ], Proxy [ Proxy [ {}, {} ], {} ] ]';
50+
const expected5 = 'Proxy [ Proxy [ Proxy [ Proxy [Object], {} ],' +
51+
' Proxy [ {}, {} ] ],\n Proxy [ Proxy [ {}, {} ]' +
52+
', Proxy [ Proxy [Object], {} ] ] ]';
53+
const expected6 = 'Proxy [ Proxy [ Proxy [ Proxy [Object], Proxy [Object]' +
54+
' ],\n Proxy [ Proxy [Object], Proxy [Object] ] ],\n' +
55+
' Proxy [ Proxy [ Proxy [Object], Proxy [Object] ],\n' +
56+
' Proxy [ Proxy [Object], Proxy [Object] ] ] ]';
57+
assert.strictEqual(util.inspect(proxy1, opts), expected1);
58+
assert.strictEqual(util.inspect(proxy2, opts), expected2);
59+
assert.strictEqual(util.inspect(proxy3, opts), expected3);
60+
assert.strictEqual(util.inspect(proxy4, opts), expected4);
61+
assert.strictEqual(util.inspect(proxy5, opts), expected5);
62+
assert.strictEqual(util.inspect(proxy6, opts), expected6);
63+
assert.strictEqual(util.inspect(proxy1), expected0);
64+
assert.strictEqual(util.inspect(proxy2), expected0);
65+
assert.strictEqual(util.inspect(proxy3), expected0);
66+
assert.strictEqual(util.inspect(proxy4), expected0);
67+
assert.strictEqual(util.inspect(proxy5), expected0);
68+
assert.strictEqual(util.inspect(proxy6), expected0);
69+
70+
// Just for fun, let's create a Proxy using Arrays.
71+
const proxy7 = new Proxy([], []);
72+
const expected7 = 'Proxy [ [], [] ]';
73+
assert.strictEqual(util.inspect(proxy7, opts), expected7);
74+
assert.strictEqual(util.inspect(proxy7), '[]');
75+
76+
// Now we're just getting silly, right?
77+
const proxy8 = new Proxy(Date, []);
78+
const proxy9 = new Proxy(Date, String);
79+
const expected8 = 'Proxy [ [Function: Date], [] ]';
80+
const expected9 = 'Proxy [ [Function: Date], [Function: String] ]';
81+
assert.strictEqual(util.inspect(proxy8, opts), expected8);
82+
assert.strictEqual(util.inspect(proxy9, opts), expected9);
83+
assert.strictEqual(util.inspect(proxy8), '[Function: Date]');
84+
assert.strictEqual(util.inspect(proxy9), '[Function: Date]');

0 commit comments

Comments
0 (0)
Morty Proxy This is a proxified and sanitized view of the page, visit original site.