Use Lexi to reduce the complexity of the language in your documentation, and to quantify and track improvements overtime.

Lexi is a GitHub action that reports readability metrics for Markdown files in your pull requests. Use these metrics to help you understand how changes impact the readability of your documentation. Lexi reports an overall readability score that is calculated based on a scaled combination of the following readability metrics:

• Flesch Reading Ease
• Gunning Fog Index
• Automated Readability Index (ARI)
• Dale-Chall Readability Score
• Coleman–Liau Index

Reports

Reports describe the overall change to each file in a pull request, and also the impact the edits make to the documentation set as a whole.

• Overall readability: describes the readability of all the documentation in your repository, along with the scores and degree of change for each file that was edited in the pull request.
• Detailed metrics: describes all available metrics for each file that was edited in the pull request.
• Averages: describes the overall readability of all the documentation in your repository for each available metric.
• Metrics targets: describes the range and ideal score for each readability metric.

View reports from previous commits

Lexi displays a report for each commit. The scores displayed in the GitHub action represent the metrics from the most recent commit.

To view metrics from previous commits in a pull request:

1. At the top right of the GitHub action, click edited.
2. Select the commit report that you want to view.

Example report

Overall readability score: 20.18 (🟢 +0.97)

File	Readability
README.md	22.36 (🟢 +3.86)

View detailed metrics

🟢 - Shows an increase in readability 🔴 - Shows a decrease in readability

File	Readability	FRE	GF	ARI	CLI	DCRS
README.md	22.36	44.11	16.67	28.7	11.85	7.66
	🟢 +3.86	🟢 +2.03	🟢 +0.75	🟢 +2.2	🔴 -0.7	🟢 +0.01

Averages:

	Readability	FRE	GF	ARI	CLI	DCRS
Average	20.18	14	16.94	19.17	15.11	9.52
	🟢 +0.97	🟢 +0.51	🟢 +0.19	🟢 +0.55	🔴 -0.17	🟢 +0

View metric targets

Metric	Range	Ideal score
Flesch Reading Ease	100 (very easy read) to 0 (extremely difficult read)	60
Gunning Fog	6 (very easy read) to 17 (extremely difficult read)	8 or less
Auto. Read. Index	6 (very easy read) to 14 (extremely difficult read)	8 or less
Coleman Liau Index	6 (very easy read) to 17 (extremely difficult read)	8 or less
Dale-Chall Readability	4.9 (very easy read) to 9.9 (extremely difficult read)	6.9 or less

Usage

Inputs

Name	Necessity	Description
github-token	Required	Use this token to post the report comment to pull requests. The GitHub Actions token can be used with ${{ secrets.GITHUB_TOKEN }}.
glob	Required	Use this pattern to match Markdown files you want to analyse.

Example workflow

This workflow reports readability metrics for .md files in your pull requests. For information, see Supported markup languages.

name: Report readability

# This action only works on pull request events
on: pull_request

jobs:
    report-readability:
        name: Report readability
        runs-on: ubuntu-latest
        steps:
            - name: Checkout repo with history
              uses: actions/checkout@v4
              with:
                  fetch-depth: 0
            - uses: Rebilly/lexi@v2
              with:
                  github-token: ${{ secrets.GITHUB_TOKEN }}
                  glob: '**/*.md'

Development

Commands

command	description
test	Run the unit tests.
lint	Run eslint on all files.
format	Run prettier on all files.
build	Build the dist file. You are required to run this locally in order to build the dist before opening a PR.
run:local:report	Run the action on two local folders, for testing and development. The first argument is the old ("base branch") folder and the sedcond argument is the new ("head branch") folder. For example yarn run:local:report ./test-data/old ./test-data/new.
run:local:debugfile	Display what the program parses from a single file, after stripping all non-wanted items from the file, and before rating the readability. For example yarn run:local:debugfile ./test-data/new/test-document.md.
playground:dev	Open the playground in local development mode for testing readability scores.

Testing

When developing the action, it may be useful to run the action locally rather than pushing a branch and running your development version on GitHub.

To test the action locally, execute the run:local:report command. This reports readability on two different directories, as though they are in one pull request.

For example: yarn run:local:report ./test-data/old ./test-data/new

Release process

1. Merge all changes into the main branch.
2. Create a new GitHub release:
   1. Enter the new tag in the release form, and choose "Create a new tag on publish". The tag must be prefixed with a v, for example v1.0.0.
      The version number must follow semantic versioning.
   2. Set the title to the version number, for example v1.0.0.
   3. Click "Generate release notes" to automatically generate the description since the last release.
   4. Click "Publish release".
3. The release is published to the Marketplace, and a workflow automatically updates the major and minor tags.

Supported markup languages

Lexi supports the following markup languages: Markdown, Markdoc, and MDX.

To configure the file formats, update the glob input in the workflow file. For more information, see Example workflow.

Example: To report on .md and .mdx files, use: glob: '**/*.{md,mdx}'.

Playground

To experiment with this tool in your web browser, and get real-time readability metric data as you edit a Markdown file, try out the playground.