Bug 272916 – Web Inspector: JavaScript breakpoint on a line with just a semicolon doesn't get triggered

• Status: NEW
• Component: Web Inspector

[Qianlang Chen]

Let's say you have the following simple JavaScript file:
    let s = "hello";
    ;
    console.log(s);

In Web Inspector's sources tab, if you create a breakpoint on line 2 (the line with just a semicolon), that breakpoint never gets triggered.

However, if that line had some other no-ops like `42;`, `() => {};`, or even if it's just an empty line, the breakpoint does get triggered.

   - My guess is that the line `;` gets optimized out or something so it's ignored, but the empty line instead registers the breakpoint on the next useful line (the line with `console.log`).

See attached for a video demo.

[Radar WebKit Bug Importer]

<rdar://problem/126707973>

[Qianlang Chen]

Created attachment 470991 [details]
Test case: The test case I used in the video demo; host this

[Qianlang Chen]

Created attachment 470992 [details]
Video demo: The first breakpoint I created does not trigger