goreadme

Overview ¶

Package goreadme generates readme markdown file from go doc.

The package can be used as a command line tool and as Github action, described below:

Github Action ¶

Github actions can be configured to update the README file automatically every time it is needed. Below there is an example that on every time a new change is pushed to the main branch, the action is trigerred, generates a new README file, and if there is a change - commits and pushes it to the main branch. In pull requests that affect the README content, if the `GITHUB_TOKEN` is given, the action will post a comment on the pull request with changes that will be made to the README file.

To use this with Github actions, add the following content to `.github/workflows/goreadme.yml`. See ./action.yml for all available input options.

on:
  push:
    branches: [main]
  pull_request:
    branches: [main]
permissions:
  # Goreadme needs permissions to update pull requests comments and change contents.
  pull-requests: write
  contents: write
jobs:
    goreadme:
        runs-on: ubuntu-latest
        steps:
        - name: Check out repository
          uses: actions/checkout@v2
        - name: Update readme according to Go doc
          uses: posener/goreadme@v1
          with:
            badge-travisci: 'true'
            badge-codecov: 'true'
            badge-godoc: 'true'
            badge-goreadme: 'true'
            # Optional: Token allows goreadme to comment the PR with diff preview.
            GITHUB_TOKEN: '${{ secrets.GITHUB_TOKEN }}'

Use as a command line tool

$ GO111MODULE=on go get github.com/posener/goreadme/cmd/goreadme
$ goreadme -h

Why Should You Use It ¶

Both Go doc and readme files are important. Go doc to be used by your user's library, and README file to welcome users to use your library. They share common content, which is usually duplicated from the doc to the readme or vice versa once the library is ready. The problem is that keeping documentation updated is important, and hard enough - keeping both updated is twice as hard.

Go Doc Instructions ¶

The formatting of the README.md is done by the go doc parser. This makes the result README.md a bit more limited. Currently, `goreadme` supports the formatting as explained in (godoc page) https://blog.golang.org/godoc-documenting-go-code, or (here) https://pkg.go.dev/github.com/fluhus/godoc-tricks. Meaning:

* A header is a single line that is separated from a paragraph above.

* Code block is recognized by indentation as Go code.

func main() {
  ...
}

* Inline code is marked with `backticks`.

* URLs will just automatically be converted to links: https://github.com/posener/goreadme

Additionally, the syntax was extended to include some more markdown features while keeping the Go doc readable:

* Bulleted and numbered lists are possible when each bullet item is followed by an empty line.

* Diff blocks are automatically detected when each line in a code block starts with a `' '`, `'-'` or `'+'`:

-removed line starts with '-'
 remained line starts with ' '
+added line starts with '+'

* A repository file can be linked when providing a path that start with `./`: ./goreadme.go.

* A link can have a link text by prefixing it with parenthesised text: (goreadme page) https://github.com/posener/goreadme.

* A link to repository file and can have a link text: (goreadme main file) ./goreamde.go.

* An image can be added by prefixing a link to an image with `(image/<image title>)`:

(image/title of image) https://github.githubassets.com/images/icons/emoji/unicode/1f44c.png

Testing ¶

The goreadme tests the test cases in the ./testdata directory. It generates readme files for all the packages in that directory and asserts that the result readme matches the existing one. When modifying goreadme behavior, there is no need to manually change these readme files. It is possible to run `WRITE_READMES=1 go test ./...` which regenerates them and check the changes match the expected (optionally using `git diff`).