Binary size reporting on CI

[lmmx]

Can we compute this on CI (I know CodeCov can do that automatically for JavaScript bundles or something? But not sure about Rust)

Will open an issue about that, but relative size like you did is fine 👍

Originally posted by @lmmx in #915 (comment)

I'll take a look at this later, but wanted to open an issue now

I built master branch as 12MB, Felix got 8 (I presume in release mode)

Sketch

We would want a GitHub Action workflow that writes a comment on the PR comparing size diff vs trunk (master branch)

Something like

name: Binary size check

on:
  pull_request:

jobs:
  size-diff:
    runs-on: ubuntu-latest
    steps:
      - name: Checkout PR branch
        uses: actions/checkout@v4

      - name: Install Rust
        uses: dtolnay/rust-toolchain@stable

      - name: Build PR binary
        run: cargo build --release
      - name: Get PR binary size
        id: prsize
        run: |
          SIZE=$(stat -c%s "target/release/your-crate-name")
          echo "size=$SIZE" >> $GITHUB_OUTPUT

      - name: Checkout master branch
        uses: actions/checkout@v4
        with:
          ref: master

      - name: Build master binary
        run: cargo build --release
      - name: Get master binary size
        id: mastersize
        run: |
          SIZE=$(stat -c%s "target/release/your-crate-name")
          echo "size=$SIZE" >> $GITHUB_OUTPUT

      - name: Post size comparison comment
        uses: marocchino/sticky-pull-request-comment@v2
        with:
          header: binary-size
          message: |
            📦 **Binary size comparison**
            
            - `master`: **${{ steps.mastersize.outputs.size }} bytes**
            - `PR`:     **${{ steps.prsize.outputs.size }} bytes**
            
            🔀 Difference: **${{ steps.prsize.outputs.size }} - ${{ steps.mastersize.outputs.size }} = ${{ steps.prsize.outputs.size && steps.mastersize.outputs.size && (steps.prsize.outputs.size - steps.mastersize.outputs.size) }} bytes**

If we can get that in Rust itself it might be simpler? Would need to look up the crates that can do that

[feliblo]

Could be useful/tries to achieve something similar: https://github.com/orf/cargo-bloat-action

[lmmx]

Could be useful/tries to achieve something similar: https://github.com/orf/cargo-bloat-action

Yep that's exactly what we're after!

[lmmx]

Ah wait, no maybe don't use that

This repository was archived by the owner on Nov 16, 2024. It is now read-only.

This is an interesting approach https://github.com/oxc-project/oxc/blob/main/.github/workflows/bloat.yml

It just writes to a step summary, so you can go and check it if you want but it won't insert a comment in the PR (possibly less disruptive to PR comments thread). Particularly nicer for PRs that would not be expected to change binary size, no PR noise

...does not seem to be running in this case because it isn't triggered on PR/push like it should be (but I presume it would work if so)?

on:
  workflow_dispatch:

[feliblo]

I agree, looks like a great, less noisy implementation!

[lmmx]

I came up with a way that shows it in the PR via a check "status" line, see demo PR and workflow source

Edit - PR submitted to add to CI in #927, turns out the check status won't work with forks (so would be no use for PRs). Removed that part, to see the result you will click through to the step summary where it shows up as an "annotation" at the top and a full report below