LGTM.com - false positive: unused argument to format

[SteVwonder]

Description of the false positive

Impressively, the analysis found a statically defined string in the main function which does not have certain keywords in it that the call to format in a separate function output_format has. Unfortunately, the analysis missed the fact that there is a second code path where output_format is called with user-provided strings (that may have those keywords).

Seemingly relevant bits:

def output_format(fmt, jobs):
    for job in jobs:
        s = fmt.format(
            id=job["id"],
            userid=job["userid"],
            username=job_username(job),
            priority=job["priority"],
            state=statetostr(job, False),
            state_single=statetostr(job, True),
            name=job["name"],
            ntasks=job["ntasks"],
            t_submit=job["t_submit"],
            t_depend=job["t_depend"],
            t_sched=job["t_sched"],
            t_run=job["t_run"],
            t_cleanup=job["t_cleanup"],
            t_inactive=job["t_inactive"],
            runtime=runtime(job, False),
            runtime_fsd=runtime_fsd(job, False),
            runtime_fsd_hyphen=runtime_fsd(job, True),
            runtime_hms=runtime_hms(job),
        )
        print(s)

def main():
    args = parse_args()
    jobs = fetch_jobs(args)

    if args.format:
        output_format(args.format, jobs)
    else:
        fmt = (
            "{id:>18} {username:<8.8} {name:<10.10} {state:<8.8} "
            "{ntasks:>6} {runtime_fsd_hyphen}"
        )
        if not args.suppress_header:
            s = fmt.format(
                id="JOBID",
                username="USER",
                name="NAME",
                state="STATE",
                ntasks="NTASKS",
                runtime_fsd_hyphen="RUNTIME",
            )
            print(s)
        output_format(fmt, jobs)

Output from LGTM:

Surplus named argument for string format. An argument named 'priority' is provided, but it is not required by format "{id:>18} {username:<8.8} {name:<10.10} {state:<8.8} {ntasks:>6} {runtime_fsd_hyphen}".

This is an easy-enough error to suppress, but I figured I'd file the false positive. Really amazing tool BTW!

URL to the alert on the project page on LGTM.com

https://lgtm.com/projects/g/flux-framework/flux-core/snapshot/ee30ed85d95632cea4f1bb1a1a4deb1046fd95b5/files/src/cmd/flux-jobs.py#xc23648d36039a520:1

[tausbn]

Thank you for your report and for your kind words!

We'll have a look at whether this false positive can be eliminated from our query. I think it should boil down to whether we can correctly identify that it is possible for there to be an "unknown" format string passed to the format method.

In the meantime, you can suppress it, as you've already noted.

Thank you for using LGTM!