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Creating recipes that run ESLint plugins

Many people have custom ESLint plugins or other CLI tools that they want to use inside of a recipe so that they can apply it to a large number of repositories.

This guide will walk you through everything you need to know in order to do that.

Prerequisites​

This guide assumes that:

  • You are somewhat familiar with recipe development. If not, consider working through our recipe authoring workshop.
  • Your ESLint plugin or CLI tool that you want to use inside of your recipe is available on NPM.

Step 1: Create a recipe repository​

The first thing you'll need to do is to create a repository for where your recipe should live.

We'd strongly recommend forking our rewrite-codemods repository as it already includes a lot of the pieces you'll need.

Step 2: Add your dependencies​

Update the package.json file inside of your repository and add your dependency or dependencies:

package.json
{
  "dependencies": {
    "eslint": "^8.56.0",
    "eslint-config-prettier": "^9.1.0",
  }
}

After that, ensure that the environment where you're building your recipe JAR can resolve the necessary dependencies from your chosen registry. This might be a public NPM registry like npmjs or unpkg, or a private one such as an Artifactory setup.

Next, make sure these dependencies are bundled as resources within the recipe JAR. Failing to do so will result in the published recipe (and the underlying Java artifact created) not knowing where dependencies are located

For example, in our rewrite-codemods repository, we use the gradle-node-plugin to run npm install and package the node modules into the JAR. You can see how we implement this in our build.gradle.kts file:

build.gradle.kts
plugins {
    id("org.openrewrite.build.recipe-library") version "latest.release"
    id("com.github.node-gradle.node") version "latest.release"
}

node {
    nodeProjectDir.set(file("build/resources/main/codemods"))
    download.set(true)
    version.set("20.18.1")
}

An example of how node modules are extracted and made accessible to Java recipes via their dependency paths can be found in our RecipeResources.java file.

Step 3: Create the recipe​

If you want to create a recipe that uses a custom ESLint plugin, you should create a YAML recipe similar to the ones in our codemods repository.

If you want to create a recipe that uses a custom CLI tool, you should create a new recipe that extends NodeBaseRecipe. Check out our ESLint recipe for a full example of this.

Keep in mind that the business logic of a codemod can be written entirely in JavaScript or TypeScript. The NodeBasedRecipe is just a wrapper that allows Moderne to run the codemod or any npm published tool. For example, in the rewrite-codemods repository, we have a JS class called putout – which is where the core logic is. There's then a Java NodeBasedRecipe wrapper that creates the recipe so it can be run in Moderne.

tip

You may find it useful to add code so that your recipe produces a data table. Data tables are tabular data that people can use for analysis purposes. They also can be useful for creating visualizations of the results.

A good example of a recipe that uses a custom tool and produces a data table is the UI5 recipe. They then use this data table to produce a visualization (yaml ipynb).

Step 4: Deploy your recipe​

With your recipe created, you'll need to deploy it as usual. If you use the Moderne Platform, check out our guide on how to import external recipes. If you are a Moderne DX user, check out our guide on how to deploy recipe artifacts with Moderne DX.