Skip to content

assert: improve AssertionError in case of "Errors"#15025

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

Closed
BridgeAR wants to merge 1 commit into from
Closed

assert: improve AssertionError in case of "Errors" #15025

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
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
23 changes: 14 additions & 9 deletions lib/internal/errors.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -35,21 +35,26 @@ class AssertionError extends Error {
if (typeof options !== 'object' || options === null) {
throw new exports.TypeError('ERR_INVALID_ARG_TYPE', 'options', 'object');
}
if (options.message) {
super(options.message);
var { actual, expected, message, operator, stackStartFunction } = options;
if (message) {
super(message);
} else {
if (actual && actual.stack && actual instanceof Error)

@thefourtheyethefourtheyeAug 26, 2017

Copy link
Copy Markdown
Contributor

Choose a reason for hiding this comment

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

Isn't actual instanceof Error itself enough?

@BridgeARBridgeARAug 26, 2017•
edited
Loading

Copy link
Copy Markdown
MemberAuthor

Choose a reason for hiding this comment

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

It is but it has a performance implication (it might not be important because it is only about errors but it is something that I always like to consider).

@jasnelljasnellAug 26, 2017

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

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

Hmmm.. actually, I believe .stack is a getter isn't it? It will have a performance impact also.

@BridgeARBridgeARAug 26, 2017•
edited
Loading

Copy link
Copy Markdown
MemberAuthor

Choose a reason for hiding this comment

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

@jasnell util.inspect will look at the stack as well. The first call to the stack is heavy and it does not matter if it is done here or later on (well it is actually not anymore as we only pass a string through instead of the error but the performance for the error will stay the same as before and the average case wont have any negative hit).

@BridgeARBridgeARAug 26, 2017

Copy link
Copy Markdown
MemberAuthor

Choose a reason for hiding this comment

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

So yes, it would be faster for Error objects (the instanceof check is added on top of the stack access) but slower for the average case.

@jasnelljasnellAug 26, 2017

Copy link
Copy Markdown
Member

Choose a reason for hiding this comment

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

Yeah. Hmm. It's likely fine. Doing it the same way internal/util isError does would likely be ok also but I'm good with it :)

actual = `${actual.name}: ${actual.message}`;
if (expected && expected.stack && expected instanceof Error)
expected = `${expected.name}: ${expected.message}`;
if (util === null) util = require('util');
super(`${util.inspect(options.actual).slice(0, 128)} ` +
`${options.operator} ${util.inspect(options.expected).slice(0, 128)}`);
super(`${util.inspect(actual).slice(0, 128)} ` +
`${operator} ${util.inspect(expected).slice(0, 128)}`);
}

this.generatedMessage = !options.message;
this.generatedMessage = !message;
this.name = 'AssertionError [ERR_ASSERTION]';
this.code = 'ERR_ASSERTION';
this.actual = options.actual;
this.expected = options.expected;
this.operator = options.operator;
Error.captureStackTrace(this, options.stackStartFunction);
this.actual = actual;
this.expected = expected;
this.operator = operator;
Error.captureStackTrace(this, stackStartFunction);
}
}

Expand Down
9 changes: 9 additions & 0 deletions test/parallel/test-assert.js
View file
Open in desktop
Original file line numberDiff line numberDiff line change
Expand Up@@ -715,3 +715,12 @@ assert.throws(() => {
}));
});
}

common.expectsError(
() => assert.strictEqual(new Error('foo'), new Error('foobar')),
{
code: 'ERR_ASSERTION',
type: assert.AssertionError,
message: /^'Error: foo' === 'Error: foobar'$/
}
);