mem.js

(() => {
    let mgr = Cc["@mozilla.org/memory-reporter-manager;1"].
        getService(Ci.nsIMemoryReporterManager);

    let amounts = [
        "vsize",
        // "vsizeMaxContiguous",
        "resident",
        // "residentFast",
        "residentPeak",
        "residentUnique",
        "heapAllocated",
        "heapOverheadFraction",
        // "JSMainRuntimeGCHeap",
        // "JSMainRuntimeTemporaryPeak",
        // "JSMainRuntimeRealmsSystem",
        // "JSMainRuntimeRealmsUser",
        // "imagesContentUsedUncompressed",
        // "storageSQLite",
        // "lowMemoryEventsVirtual",
        // "lowMemoryEventsCommitSpace",
        // "lowMemoryEventsPhysical",
        // "ghostWindows",
        // "pageFaultsHard",
    ];

    // There's something unsettling about actually wanting the
    // notorious leftpad dependency.
    let padding = "                            ";
    for (let i = 0; i < amounts.length; i++) {
        let amount = mgr[amounts[i]];
        dump(`amounts: ${amounts[i]}: ${padding.substring(amounts[i].length)} ${amount}\n`);
    }

    const { AppConstants } = ChromeUtils.import(
        "resource://gre/modules/AppConstants.jsm"
    );
    

    // Can't use app info from xpcshell.
    // let appInfo = Cc["@mozilla.org/xre/app-info;1"]
    //     .getService(Ci.nsIXULAppInfo);

    dump(`version: ${AppConstants.MOZ_APP_VERSION} (${AppConstants.MOZ_BUILDID})\n`);
})();