Servo.org website

• How to start a local dev server
• How to list commits that landed in each nightly
• How to list this year’s pull request contributors
• How to analyse WPT pass rate improvements
• How to linkify GitHub handles and pull requests when finishing a post
• How to calculate monthly recurring donations
• Triaging commits in nightlies for monthly updates
• Hints for writing about changes
• Corrections

How to start a local dev server

1. npm install
2. npm run start

How to list commits that landed in each nightly

Note that the list of nightly builds is cached in tools/runs.json, so if it exists, you will need to delete it to fetch an updated list.

Make sure your Servo checkout is on the main branch, and that the branch is up to date. Then run the script below, passing it the path to your checkout:

$ rm tools/runs.json  # Optional: clear CI history cache
$ tools/list-commits-by-nightly.sh /path/to/servo

How to list this year’s pull request contributors

$ > 2023.json tools/list-pull-requests.sh servo/servo 2023 2023
$ < 2023.json jq -r .user.login | sort | uniq -c | sort -nr

Or for some other range of dates:

$ > pull-requests.json tools/list-pull-requests.sh servo/servo 2023-03-16 2024-03-16

How to analyse WPT pass rate improvements

1. Go to https://wpt.servo.org/ and open devtools
2. fromDate = "2024-01-25"
3. toDate = "2024-02-26"
4. Run the code below

((data, ...dates) => {
    const stride = data.area_keys.length;
    const rows = dates.map(expectedDate => data.scores.find(([date]) => date == expectedDate));
    rows.forEach((row, i) => {
        if (row == null) throw `no results for ${dates[i]}!`;
        if (row.length != 3 + stride + 2 + stride) throw "schema change? bad length";
        if (row[0] != dates[i]) throw "unreachable! incorrect date in [0]";
        if (!/^[0-9a-f]{9}$/.test(row[1])) throw "schema change? expected commit hash in [1]";
        if (!/^0[.]0[.]1-[0-9a-f]{7}$/.test(row[2])) throw "schema change? expected version in [2]";
        if (!/^[0-9a-f]{9}$/.test(row[3+stride])) throw "schema change? expected commit hash in [3+stride]";
        if (!/^0[.]0[.]1-[0-9a-f]{7}$/.test(row[4+stride])) throw "schema change? expected version in [4+stride]";
    });
    const areas = data.area_keys.map((key, i) => ({key, results: rows.map((row, j) => ({
        date: dates[j],
        legacy: row[3+i],
        servo: row[5+stride+i],
    }))}));
    console.log(">>> areas", areas);
    const analysis = areas
        .map(({key, results: [p, q]}) => ({
            key,
            regressionWas: p.legacy - p.servo,
            regressionNow: q.legacy - q.servo,
            legacyWas: p.legacy,
            legacyNow: q.legacy,
            servoWas: p.servo,
            servoNow: q.servo,
        }))
        .map(({key, regressionWas, regressionNow, legacyWas, legacyNow, servoWas, servoNow}) => ({
            key, regressionWas, regressionNow, legacyWas, legacyNow, servoWas, servoNow,
            legacyDelta: delta(legacyWas, legacyNow),
            servoDelta: delta(servoWas, servoNow),
            regressionDelta: delta(regressionWas, regressionNow),
        }));
    console.log(">>> analysis", analysis);
    const deltaAnalysisText = analysis
        .sort((p,q) => q.servoDelta.pp - p.servoDelta.pp)
        .map(({key, servoDelta, servoNow}) => `${key} (${servoDelta.pp.toFixed(1)}pp to ${(servoNow/10).toFixed(1)}%)\n`);
    console.log(`>>> top deltas (servo, pp):\n${deltaAnalysisText.join("")}`);
    const regressionAnalysisText = analysis
        .filter(({regressionWas}) => regressionWas >= 0)
        .sort((p,q) => p.regressionDelta.percent - q.regressionDelta.percent)
        .map(({key, regressionDelta, regressionWas, regressionNow}) => `${key} (${regressionDelta.percent.toFixed(1)}% from ${(regressionWas/10).toFixed(1)}pp to ${(regressionNow/10).toFixed(1)}pp)\n`);
    console.log(`>>> top cuts in legacy regression (%):\n${regressionAnalysisText.join("")}`);
    function delta(p,q) { return {pp: (q-p)/10, percent: 100*(q-p)/p}; }
})(await (await fetch("scores.json")).json(), fromDate, toDate)

How to linkify GitHub handles and pull requests when finishing a post

To avoid false positives, be sure to step through each replacement rather than using Replace All.

• Replace @([0-9A-Za-z_.-]+) with [@$1](https://github.com/$1)
• Replace #([0-9]+) with [#$1](https://github.com/servo/servo/pull/$1)
• Replace ([0-9A-Za-z_.-]+)#([0-9]+) with [$1#$2](https://github.com/servo/$1/pull/$2)
• Replace ([0-9A-Za-z_.-]+)/([0-9A-Za-z_.-]+)#([0-9]+) with [$1/$2#$3](https://github.com/$1/$2/pull/$3)

How to calculate monthly recurring donations

OpenCollective:

• Go to https://opencollective.com/dashboard/servo/incoming-contributions?limit=1000&status=ACTIVE&status=ERROR&type=RECURRING
• Make sure there is only one page of results; if there are more pages, we’ll need to update the process like we did for GitHub
• Make sure there is a column with “month” or “year”, because some table filters hide that column
• Run this code in devtools:

$$("table tbody tr")
    .map(tr => [...tr.cells][2].innerText.match(/[$](\S+)\s*USD\s*[/]\s*(\S+)/))
    .map(match => match && [+match[1].replace(/[.,]/g, ""), match[2]])
        .map(([cents, period]) => cents / {month:1,year:12}[period])
        .reduce((result, cents) => result + cents, 0)

• The result is USD cents/month

GitHub:

• Go to https://github.com/sponsors/servo/dashboard/your_sponsors
• Run this code in devtools:

seen = new Set; centsPerMonth = 0

• Click through each page of the table and run this code in devtools:

centsPerMonth += $$("table tbody tr")
    .map(tr => [...tr.cells])
    .map(cells => [cells[1].querySelector("a").href, cells])
    .filter(([donorHref, cells]) => !seen.has(donorHref))
    .map(([donorHref, cells]) => (seen.add(donorHref), cells))
    .map(cells => cells.slice(2,4).map(td => td.innerText).join(" "))
    .map(text => text.match(/[$](\S+)\s*(.+)/))
    .map(match => [100 * match[1], match[2].replace(/ [(]custom[)]/, "")])
    .filter(([cents, period]) => period != "One time")
    .map(([cents, period]) => cents / {Monthly:1}[period])
    .reduce((result, cents) => result + cents, 0)

• After running it on every page, the result is USD cents/month

LFX:

• Go to https://crowdfunding.lfx.linuxfoundation.org/projects/e98e012f-479e-45d0-8781-4d7f616baa9d/financial
  • You may need to open it in private browsing to avoid getting a 404, not sure why
• Manually add up the amounts for one month, stopping when you see the same donor repeated

Triaging commits in nightlies for monthly updates

Generally we want to include...

• gecko upgrades (stylo, webrender, mozjs)
• web-facing changes
• DX-affecting CI changes
• MSRV and Rust edition changes
• platform support changes
• platform bustage fixes
• crash fixes

And generally we want to exclude...

• dependabot updates (“build(deps)”)
• WPT imports (“Update web-platform-tests”)
• lint and warning fixes
• other CI changes
• refactors (unless large-scale)
• dependency cleanups

Hints for writing about changes

Always check the correct names of people and API features. People like it when their names are spelled correctly, of course, but sometimes authors refer to API features by incorrect names. When in doubt, check the spec. For example, servo#32642 says “ShaderCompilationInfo” in the title, but the interface is actually GPUCompilationInfo, returned by the getCompilationInfo() method on GPUShaderModule (July 2024).

Always check for patches with co-authors. Look for any “Co-authored-by” lines in the pull request description, as well as in the descriptions of commits with multiple avatars in the commits tab. If a commit has a “Co-authored-by” line, it will have multiple avatars, but a commit can also have multiple avatars for other reasons, like the committer being different from the author. For example, servo#32576 has a co-author in both the pull request description and the description of its only commit (July 2024).

Check for partial implementations. Sometimes a patch appears to implement an API feature, but the feature may actually be incomplete. If support is not complete or mostly complete, describe only what is supported or use phrases like “partial”, “basic”, or “initial support”. For example, the title of servo#32576 suggests that it implements FontFaceSet, but the description and diff explains that only document.fonts.ready is actually implemented (July 2024).

Check for experimental implementations. Sometimes a patch appears to implement an API feature, but the feature is gated by a pref. If the user needs to enable a pref to use a feature, make sure you mention that. For example, servo#31108 implements ResizeObserver, but the user needs to run servoshell with --pref dom.resize_observer.enabled (June 2024).

Check for disabled implementations. Sometimes a patch appears to implement an API feature, but the feature is still completely disabled. In this case, it may not be worth writing about the feature at all, unless a lot of work went into the patch. For example, servo#30752 implements some :has() selector features, but the feature is completely disabled (November 2023).

Corrections

When we make mistakes, we issue corrections on the blog and on social media.

• November 2023 — An earlier version of this post said that Servo now supports the :has() selector, but this was incorrect. While some of the code implementing the feature has landed, it is not yet enabled.
• March 2024 — An earlier version of this post said that over 94% of amounts donated to Servo go directly to the project, with only 6% in fees, but this was incorrect. The actual fees depend on the payment method and the amount you donate, but in most cases they are between 10% and 20%. We are still working on clarifying the exact rules about fees with our crowdfunding platforms, so check our Sponsorship page for the latest information.