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GitHub Action

Bundle size diff

v1.1.0 Latest version

Bundle size diff

bar-chart-2

Bundle size diff

Report webpack bundle size change in the PR

Installation

Copy and paste the following snippet into your .yml file.

              

- name: Bundle size diff

uses: NejcZdovc/[email protected]

Learn more about this action in NejcZdovc/bundle-size-diff

Choose a version

Bundle size diff from webpack with Github Actions

Action that allows you to generate diff report between branches. This way you always know when things go sideways :)

image

Inputs

Name Description Required
base_path Path of base branch stats file yes
pr_path Path of PR branch stats file yes
excluded_assets Regex that will exclude some assets no

Output

Name Description Return
success Tells you if diff was successfully generated 'true' / 'false'
base_file_size Bundle size of base branch that you are targeting bytes
base_file_string Formatted bundle size of base branch example: 8.1 kb
pr_file_size Bundle size of PR branch bytes
pr_file_string Formatted bundle size of PR branch example: 8.1 kb
diff_file_size Diff size of compared branches bytes
diff_file_string Formatted diff size between branches example: 8.1 kb
percent Diff size of compared presented in percentage example: 0.14%

Usage

The key thing that you will need to do when using this action is to create a stats file from webpack.

You can see the simple example that we used in this repo for testing purposes.
You can read more about webpack-bundle-analyzer on authors page.

To save action minutes I would suggest that you have an action that generates a new state file every time that you merge commit in the main branch.

An alternative approach is to generate a state file for a base branch on the fly. This approach we used in our example as it's a little bit more complicated.

Let's break down our workflow file.

Build base

The first job is for building a base branch. In most cases, this would be the main/master branch.

Important note here is that we add ref: ${{ github.base_ref }} in checkout action. This tells action to checkout base that you set for the PR.

Then we just do regular dependency install and build of our script.

The next section is crucial. We are doing multiple jobs to build stats files so we need to store this data between runs. To accomplish that we will be using artifacts. Because we only need this data for short period I like to set expiration to 1 day retention-days: 1.

build-base:
  name: Build base
  runs-on: ubuntu-latest
  steps:
  - name: Checkout
    uses: actions/checkout@v2
    with:
      ref: ${{ github.base_ref }}

  - name: Install dependencies
    run: npm ci
    env:
      NODE_AUTH_TOKEN: ${{secrets.TOKEN_REPO}}

  - name: Build
    run: npm run build-demo

  - name: Upload base stats.json
    uses: actions/upload-artifact@v2
    with:
      name: base
      path: ./demo/demo-dist/stats.json
      retention-days: 1

Build PR

Next thing is to build PR.

As you can see checkout now just checkouts default which is head of the PR.

build-pr:
  name: Build PR
  runs-on: ubuntu-latest
  steps:
  - name: Checkout
    uses: actions/checkout@v2

  - name: Install dependencies
    run: npm ci
    env:
      NODE_AUTH_TOKEN: ${{secrets.TOKEN_REPO}}

  - name: Build
    run: npm run build-demo

  - name: Upload base stats.json
    uses: actions/upload-artifact@v2
    with:
      name: pr
      path: ./demo/demo-dist/stats.json
      retention-days: 1

Compare builds

Now that we have stats files ready, we just need to download them which we are doing with actions/download-artifact, and pass them to our action.

In the last section, we take values that were returned from our action and print it out as a nice table via NejcZdovc/comment-pr.

report:
  name: Generate report
  runs-on: ubuntu-latest
  needs: [build-base, build-pr]

  steps:
  - name: Checkout PR
    uses: actions/checkout@v2

  - name: Download base stats
    uses: actions/download-artifact@v2
    with:
      name: base
      path: base

  - name: Download PR stats
    uses: actions/download-artifact@v2
    with:
      name: pr
      path: pr

  - name: Get diff
    id: get-diff
    uses: NejcZdovc/bundle-size-diff@v1
    with:
      base_path: './base/stats.json'
      pr_path: './pr/stats.json'

  - name: Comment
    uses: NejcZdovc/[email protected]
    with:
      file: 'comment.md'
    env:
      GITHUB_TOKEN: ${{secrets.GITHUB_TOKEN}}
      OLD: ${{steps.get-diff.outputs.base_file_string}}
      NEW: ${{steps.get-diff.outputs.pr_file_string}}
      DIFF: ${{steps.get-diff.outputs.diff_file_string}}
      DIFF_PERCENT: ${{steps.get-diff.outputs.percent}}

Bugs

Please file an issue for bugs, missing documentation, or unexpected behavior.

LICENSE

MIT