dart_apitool 0.5.0

A tool to analyze the public API of a package, create a model of it and diff it against another version to check semver.

Dart API Tool

A tool to analyze the public API of a package and create a model of it. It also allows to use that model to compare the public API with a newer version and check if the version follows semver correctly.

Installation

To install activate the tool via dart pub:

dart pub global activate dart_apitool

Screenshot

Usage

After activation the tool is usable via

dart-apitool

A set of utilities for Package APIs

Usage: dart-apitool <command> [arguments]

Global options:
-h, --help    Print this usage information.

Available commands:
  diff      Creates a diff of 2 given packages.
  extract   Extracts the API from the given package ref.

Run "dart-apitool help <command>" for more information about a command.

extract

Extracts the API from the given package ref.

Usage: dart-apitool extract [arguments]
-h, --help                     Print this usage information.
    --input (mandatory)        Input package ref. Package reference can be one of:
                               - directory path pointing to a package on disk
                                 (e.g. /path/to/package)
                               - an extract file generated by dart-apitool
                                 (e.g. packageApi.json)
                               - any package from pub
                                 (e.g. pub://package_name/version)
    --output                   Output file for the extracted Package API.
                               If not specified the extracted API will be printed to the console.
    --no-merge-base-classes    Disables base class merging.

diff

Creates a diff of 2 given packages.

Usage: dart-apitool diff [arguments]
-h, --help                      Print this usage information.
    --old (mandatory)           Old package reference. Package reference can be one of:
                                - directory path pointing to a package on disk
                                  (e.g. /path/to/package)
                                - an extract file generated by dart-apitool
                                  (e.g. packageApi.json)
                                - any package from pub
                                  (e.g. pub://package_name/version)
    --new (mandatory)           New package reference. Package reference can be one of:
                                - directory path pointing to a package on disk
                                  (e.g. /path/to/package)
                                - an extract file generated by dart-apitool
                                  (e.g. packageApi.json)
                                - any package from pub
                                  (e.g. pub://package_name/version)
    --[no-]check-versions       Determines if the version of the new package should be checked.
                                Takes the changes of the diff and checks if the new version follows the semver rules.
                                Influences tool return value.
                                (defaults to on)
    --[no-]ignore-prerelease    Determines if the pre-release aspect of the version shall be ignored when checking versions.
                                This only makes sense in combination with --check-versions.
                                You may want to do this if you want to make sure
                                (in your CI) that the version - once ready - matches semver.
    --no-merge-base-classes     Disables base class merging.

Integration

How to best integrate dart-apitool in your CI and release process highly depends on your setup.

In general, you need to have a reference of what has been released before in order to do a diff to the new sources.

To do that you have several options:

1. store the last released version next to your source code
2. store the extracted public API next to your source code
3. use whatever knowledge your release process has to get a copy of the previously released version

Depending on what you have as a reference you can call dart-apitool using the appropriate package ref for the old parameter:

1. pub://[package_name]/[package-version] if you know the last released version and your package is hosted at pub
2. [path-to-extract.json] to load the stored public API model
3. [path-to-copy] to get the public API model from the obtained reference copy

CI

For an example how to integrate dart-apitool in your CI (to make sure that the current pre-release version is targeting the right version number) you can refer to the workflow used by this repository. dart-apitool uses approach 1 (store the last released version next to the source code) For your convenience there is a reusable workflow that you can integrate in your workflow.

  semver:
    uses: devmil/dart_apitool/.github/workflows/check_version.yml@workflow/v1
    with:
      runs-on: [your build node] # defaults to ubuntu-latest
      old: [package ref to old] # required, e.g. "pub://dart_apitool/<old version>"
      new: [package ref to new] # e.g. "."
      ignore-prerelease: ['on' if you want to check against the future version (without pre-release), defaults to 'off'] # e.g. 'on'
      flutter-channel: [flutter channel to use, defaults to 'stable'] # e.g. 'stable'
      flutter-version: [flutter version to use, defaults to 'any'] # e.g. 'any'

Release

Your release process has to make sure that the reference is stored somehow. The easiest way to do that is to store a file containing the last released version next to the source code (dart-apitool does that). The release process can also use dart-apitool to make sure that the new version matches the changes it contains.

Contributions

Any kind of contribution is very welcome. Either you have found a false positive or you miss something in the public API model that needs to be analyzed or if you want to contribute directly. Feel free to use the issues to create requests.

Limitations

It doesn't cover all potential API changes that might lead to breaking changes.

It does not look into implementations

Imagine a class:

class MyClass<T> {
  String doSomething(T arg) {
    final castedArg = arg as SomeBaseClass;
    return castedArg.baseClassMethod();
  }
}

that got changed to

class MyClass<T> {
  String doSomething(T arg) {
    final castedArg = arg as SomeOtherBaseClass;
    return castedArg.otherBaseClassMethod();
  }
}

Changes in the implementation are not detected.

It has no idea what a Plugin, Swift or Kotlin is

Any changes on platform-specific level are not detected.

🪛 Changing the minSdkVersion?

🪓 Updating your Podspec with breaking changes?

dart-apitool won't care! 🤷

Verdict

You have to keep your eyes 👀 open and always remember the public API!

dart-apitool can help you find problematic changes on Dart API level, but it can't detect everything. 😉