Bug 176074 – Web Inspector: Use strict mode for String.prototype.* methods

• Status: RESOLVED
• Resolution: FIXED
• Component: Web Inspector

[Nikita Vasilyev]

For ECMAScript classes, strict mode is implicit.

In Utilities.js, we don't use classes. Currently, strict mode is only used for "truncate" method: https://bugs.webkit.org/show_bug.cgi?id=149708#c8.
We should use it for other.

When strict mode isn't used, `this` is always an object.

    > "abc".trimEnd(5)
    < String {0: "a", 1: "b", 2: "c", length: 3}

This may lead to unexpected behavior:

    > "abc".trimEnd(5) === "abc"
    < false

It also makes String.prototype.* operations slower.

[Nikita Vasilyev]

All String.prototype.* methods except String.prototype.extendedLocaleCompare are untested 😱

[Nikita Vasilyev]

Created attachment 319304 [details]
WIP

This requires more work than I anticipated. Tabling this until the week of tests.

[Radar WebKit Bug Importer]

<rdar://problem/166488067>

[Brandon]

Pull request: https://github.com/WebKit/WebKit/pull/55378

[EWS]

Committed 304532@main (7983d6668967): <https://commits.webkit.org/304532@main>

Reviewed commits have been landed. Closing PR #55378 and removing active labels.