Console format specifiers on Symbols

Confirmed Issue #15432105 • Assigned to Mike J.


Dominic F.
Jan 12, 2018
This issue is public.
Found in
  • Microsoft Edge
  • Chrome
  • Safari
  • Firefox
Standard affected
Console Standard

Reported by 1 person

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Steps to reproduce

Run the JavaScript appearing in the <script> tag in the test in To see the expected output of using Console format specifiers on Symbols, either run the code in the pull request or checkout the attached “expected.png”

NOTE This is not just a basic web-compat bug, as Edge prints a really nasty error code for some of these (can’t confirm for all as I do not have Edge currently)


1 attachment

Comments and activity

  • P.S. The tests have been updated to

    1. Be more inclusive to all console methods using format specifiers
    2. To ensure we’re not testing console.dir, since console.dir is not spec’d to take in format specifiers. This was a mistake in the original tests. I’m noting this here since there has been some confusion on this.
  • Microsoft Edge Team

    Changed Assigned To to “Steven K.”

    Changed Assigned To to “edgedevtoolstri”

    Changed Status to “Confirmed”

    Changed Assigned To from “edgedevtoolstri” to “Yong C.”

  • Just for reference, the updated plan for evaluating %i/d/f format specifiers can be found at

    Presently, as per the recent spec changes, we do not throw when the %s specifier is applied to Symbols. See (

  • Microsoft Edge Team

    Changed Assigned To from “Yong C.” to “Mike J.”

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