Hi Cecil, it's hard to say much without a repro. I'd start by trying the V8 flag --trace-block-coverage ( https://source.chromium.org/chromium/chromium/src/+/main:v8/src/debug/debug-coverage.cc;l=481;drc=5f2ed43ac6add2683505e130be73826cbb3dddfd). If that doesn't help, the next step would be to debug more around Coverage::Collect.
Also, I'd suggest to file a report at crbug.com/v8/new to continue the conversation since bug reports are easier to track than mails :) On Tue, Sep 20, 2022 at 9:39 PM 'Cecil King' via v8-dev < [email protected]> wrote: > Hello. > > My first post here. I'm looking for advice on debugging an issue with the > v8 code coverage. > > I'm using startPreciseCoverage / takePreciseCoverage to extract code > coverage data from Chrome (i.e. v8). > > My issue: data from uncovered functions are missing from the dumped data. > For example, assume the handleSubmit function in authors.js is not > called. I expect to see this: > { > "scriptId": "16", > "url": > "file:///home/<user>/v8-chrome-coverage-wdio-sync/public/js/authors.js", > "functions": [ > { > "functionName": "", > "ranges": [{ "startOffset": 0, "endOffset": 828, "count": 1 }], > "isBlockCoverage": true }, > { > "functionName": "showContent", > "ranges": [{ "startOffset": 71, "endOffset": 448, "count": 1 > }], > "isBlockCoverage": true > }, > { > "functionName": "", > "ranges": [{ "startOffset": 274, "endOffset": 444, "count": 3 > }], > "isBlockCoverage": true > }, > { > "functionName": "handleSubmit", > "ranges": [{ "startOffset": 450, "endOffset": 703, "count": 0 > }], > "isBlockCoverage": false > } > ] > }, > > but instead I get this: > { > "scriptId": "16", > "url": > "file:///home/<user>/v8-chrome-coverage-wdio-sync/public/js/authors.js", > "functions": [ > { > "functionName": "", > "ranges": [{ "startOffset": 0, "endOffset": 828, "count": 1 }], > "isBlockCoverage": true }, > { > "functionName": "showContent", > "ranges": [{ "startOffset": 71, "endOffset": 448, "count": 1 > }], > "isBlockCoverage": true > }, > { > "functionName": "", > "ranges": [{ "startOffset": 274, "endOffset": 444, "count": 3 > }], > "isBlockCoverage": true > } > ] > }, > > i.e. there is no data at all on the uncovered function. This causes the c8 > report tool to generate an invalid report. > > The above is what I observe on my company's codebase. I tried to create > simple reproductions that I could share, however all my simple projects are > working fine. > > Any suggestions or tips on what I could try to debug the problem would be > appreciated. > > (FYI ... here's a working version of the flow on a smaller project: > https://github.com/cek333/v8-chrome-coverage-wdio-sync) > > Thanks. > > -- > -- > v8-dev mailing list > [email protected] > http://groups.google.com/group/v8-dev > --- > You received this message because you are subscribed to the Google Groups > "v8-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion on the web visit > https://groups.google.com/d/msgid/v8-dev/22d16033-590f-4de3-86de-a6aa6ebcbb74n%40googlegroups.com > <https://groups.google.com/d/msgid/v8-dev/22d16033-590f-4de3-86de-a6aa6ebcbb74n%40googlegroups.com?utm_medium=email&utm_source=footer> > . > -- -- v8-dev mailing list [email protected] http://groups.google.com/group/v8-dev --- You received this message because you are subscribed to the Google Groups "v8-dev" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/d/msgid/v8-dev/CAH3p7oO2sAa%2BrCZJdLGrgWXj3D%3DOW32MF__xXkir%2BND_ZvaTjg%40mail.gmail.com.
