Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Symbol key props visible in inspection by default #9726

Closed
wants to merge 5 commits into from
Closed

Symbol key props visible in inspection by default #9726

Show file tree
Hide file tree
Changes from 3 commits
Commits
Show all changes
5 commits
Select commit Hold shift + click to select a range
903f353
Symbol key props visible in inspection by default
mightyiam Nov 21, 2016
192d79a
test/parallel/test-util-inspect: const UTC -> const UIC
mightyiam Nov 22, 2016
3ace6a9
Excl. non-enumerable property symbols from inspection by default
mightyiam Nov 24, 2016
8e73c95
lib/util: use const for symbolKeys & enumSymbolKeys
mightyiam Nov 24, 2016
3cbd847
lib/util: fix indentation of enumSymbolKeys's filter call
mightyiam Nov 24, 2016
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
7 changes: 5 additions & 2 deletions lib/util.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -371,10 +371,13 @@ function formatValue(ctx, value, recurseTimes) {
// Look up the keys of the object.
var keys = Object.keys(value);
var visibleKeys = arrayToHash(keys);
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I don't fully understand what goes on with keys vs. visibleKeys, yet, this seems to work.

var symbolKeys = Object.getOwnPropertySymbols(value);
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I haven’t run this but right now this looks like this will include even *non-*enumerable Symbol properties?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yup. That is how Object.getOwnPropertySymbols works. It is like the conversation between it and Object.getOwnPropertyNames is:

  • Object.getOwnPropertyNames: Hey, Symbol. You may join. But don't expect me to list you, even if you're enumerable...
  • Symbol: 😐
  • Object.getOwnPropertySymbols: Gee, did you see that guy? Tell you what, Symbol. I'll list all of you, regardless!
  • Symbol: 😟
  • Object.getOwnPropertyNames: 😦
  • Object.getOwnPropertySymbols: 😊
  • Symbol: 😕

I wouldn't mind changing it to exclude non-enumerable symbol-keyed props. Should I?

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Well… it seems a bit weird to list only enumerable string properties but all Symbol properties by default?

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I just don't know the reasons for not listing non-enumerable properties. For the sake of explaining my experience with the matter, I'll testify that I:

  1. never made a property non-enumerable before examining this issue
  2. never had to examine the non-enumerable properties of an object. At least not that I know of.

So, it may help that one with experience with the topic of enumerability and non-enumerability will share his thoughts. Also, the thoughts of one who knows the intention of symbols in this regard and why this is the behavior of Object.getOwnPropertySymbols.

var enumSymbolKeys = symbolKeys
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit: This one can be const

.filter((key) => value.propertyIsEnumerable(key));
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

nit: I think we generally indent statement continuations by 4 spaces, not 2

keys = keys.concat(enumSymbolKeys);

if (ctx.showHidden) {
keys = Object.getOwnPropertyNames(value);
keys = keys.concat(Object.getOwnPropertySymbols(value));
keys = Object.getOwnPropertyNames(value).concat(symbolKeys);
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This is the same result. The change is to not get the symbols twice.

}

// This could be a boxed primitive (new String(), etc.), check valueOf()
Expand Down
20 changes: 15 additions & 5 deletions test/parallel/test-util-inspect.js
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -588,8 +588,9 @@ assert.doesNotThrow(function() {
'{ a: 123, inspect: [Function: inspect] }');

const subject = { a: 123, [util.inspect.custom]() { return this; } };
const UIC = 'util.inspect.custom';
assert.strictEqual(util.inspect(subject),
'{ a: 123 }');
`{ a: 123,\n [Symbol(${UIC})]: [Function: [${UIC}]] }`);
}

// util.inspect with "colors" option should produce as many lines as without it
Expand Down Expand Up @@ -659,18 +660,27 @@ if (typeof Symbol !== 'undefined') {

subject[Symbol('symbol')] = 42;

assert.strictEqual(util.inspect(subject), '{}');
assert.strictEqual(util.inspect(subject), '{ [Symbol(symbol)]: 42 }');
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This demonstrates the change.

Copy link
Contributor Author

@mightyiam mightyiam Nov 21, 2016 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Just the way I like it 😉

assert.strictEqual(
util.inspect(subject, options),
'{ [Symbol(symbol)]: 42 }'
);

Object.defineProperty(
subject,
Symbol(),
{enumerable: false, value: 'non-enum'});
assert.strictEqual(util.inspect(subject), '{ [Symbol(symbol)]: 42 }');
Copy link
Contributor Author

@mightyiam mightyiam Nov 21, 2016 •
edited
Loading

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This assertion is removed because we already have an assertion above that symbol key properties are visible with showHidden.

assert.strictEqual(
util.inspect(subject, options),
'{ [Symbol(symbol)]: 42, [Symbol()]: \'non-enum\' }'
);

subject = [1, 2, 3];
subject[Symbol('symbol')] = 42;

assert.strictEqual(util.inspect(subject), '[ 1, 2, 3 ]');
assert.strictEqual(util.inspect(subject, options),
'[ 1, 2, 3, [length]: 3, [Symbol(symbol)]: 42 ]');
assert.strictEqual(util.inspect(subject),
'[ 1, 2, 3, [Symbol(symbol)]: 42 ]');
Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

So in essence, this assertion is not instead of the one in 672, but instead of the one in 671. I guess it shows that symbol key properties can coexist peacefully with other properties in inspection. Or something about the order of properties? In any case, I'm guessing that the essence is preserved.

}

// test Set
Expand Down