prettier-maven-plugin

Maven plugin for running prettier-java during a build. Node, prettier, and prettier-java are downloaded automatically as needed.

There is a check goal which (optionally) fails the build if code isn't formatted correctly, and a write goal which rewrites the source code in place. A common setup might be to use the write goal during local builds, and the check goal during CI builds.

Example Usage

This example will run the check goal inside of Travis CI, and the write goal outside of Travis CI. You can update the profile activation conditions based on the CI tool you use.

<properties>
  <!-- By default just re-write code with prettier -->
  <plugin.prettier.goal>write</plugin.prettier.goal>
</properties>

<build>
  <plugins>
    <plugin>
      <groupId>com.hubspot.maven.plugins</groupId>
      <artifactId>prettier-maven-plugin</artifactId>
      <version>0.16</version>
      <configuration>
        <prettierJavaVersion>2.0.0</prettierJavaVersion>
        <printWidth>90</printWidth>
        <tabWidth>2</tabWidth>
        <useTabs>false</useTabs>
        <ignoreConfigFile>true</ignoreConfigFile>
        <ignoreEditorConfig>true</ignoreEditorConfig>
        <!-- Use <inputGlobs> to override the default input patterns -->
        <inputGlobs>
          <!-- These are the default patterns, you can omit <inputGlobs> entirely unless you want to override them -->
          <inputGlob>src/main/java/**/*.java</inputGlob>
          <inputGlob>src/test/java/**/*.java</inputGlob>
        </inputGlobs>
      </configuration>
      <executions>
        <execution>
          <phase>validate</phase>
          <goals>
            <goal>${plugin.prettier.goal}</goal>
          </goals>
        </execution>
      </executions>
    </plugin>
  </plugins>
</build>

<profiles>
  <profile>
    <id>travis</id>
    <activation>
      <property>
        <name>env.TRAVIS</name>
      </property>
    </activation>
    <properties>
      <!-- But in our CI environment we want to validate that code is formatted -->
      <plugin.prettier.goal>check</plugin.prettier.goal>
    </properties>
  </profile>
</profiles>

You can also run in a one-off fashion via the commandline:
mvn prettier:check
or
mvn prettier:write

You can also run mvn prettier:print-args in order to confirm the configuration values

To format additional directories or file types via the commandline, you can pass a comma-separated list of patterns, for example:
mvn prettier:write '-Dprettier.inputGlobs=src/main/java/**/*.java,src/test/java/**/*.java,src/main/js/**/*.js'

Configuration

If you want to customize the behavior of prettier, you can use a normal prettier configuration file. Alternatively, you can configure prettier directly via the Maven plugin using the following options:

Name	-D property name	Default Value	Description
skip	N/A	false	If set to true, plugin execution will be skipped
fail	N/A	true	Only appplies to check goal. If set to true, the plugin execution will fail if any unformatted files are found
generateDiff	N/A	false	Only appplies to check goal. Be sure to have to sh and diff in your PATH. If set to true, a diff will be generated between the current code and the prettier-formatted code.
diffGenerator	prettier.diffGenerator	_	Only appplies to check goal. Can be used to supply a custom implementation of DiffGenerator
nodeVersion	prettier.nodeVersion	16.13.1	Controls version of Node used to run prettier-java.
nodePath	prettier.nodePath	-	Can be used to supply your own node executable, rather than having the plugin download it. To use the version of node on your $PATH, you can simply set this option to node.
npmPath	prettier.npmPath	-	Can be used to supply your own npm executable, rather than having the plugin download it. To use the version of npm on your $PATH, you can simply set this option to npm.
prettierJavaVersion	prettier.prettierJavaVersion	0.7.0	Controls version of prettier-java that is used.
printWidth	prettier.printWidth	null	If set, will be passed to prettier as --print-width. More information here
tabWidth	prettier.tabWidth	null	If set, will be passed to prettier as --tab-width. More information here
useTabs	prettier.useTabs	null	If set, will be passed to prettier as --use-tabs. More information here
endOfLine	prettier.endOfLine	null	If set, will be passed to prettier as --end-of-line. More information here
ignoreConfigFile	prettier.ignoreConfigFile	false	If set to true, pretter will be invoked with --no-config. More information here
ignoreEditorConfig	prettier.ignoreEditorConfig	false	If set to true, pretter will be invoked with --no-editorconfig. More information here
inputGlobs	prettier.inputGlobs	src/{main,test}/java/**/*.java	Controls the input paths passed to prettier, useful for formatting additional directories or file types. More information here
disableGenericsLinebreaks	prettier.disableGenericsLinebreaks	false	Prevents prettier from adding linebreaks to generic type declarations (see #78 for more background)

Generic Linebreaks

The disableGenericsLinebreaks option is implemented by patching prettier-plugin-java after downloading. As new versions of prettier-java are released, we may need to create updated patches. The basic flow for creating a new patch is:

1. Download the new version of prettier-java

• cd /tmp && npm install prettier-plugin-java@{version}

2. Make two copies of prettier-java code

• mkdir -p a/node_modules && cp -r node_modules/prettier-plugin-java a/node_modules)
• mkdir -p b/node_modules && cp -r node_modules/prettier-plugin-java b/node_modules)

3. Update the code within b/node_modules/prettier-plugin-java/dist/ as needed to revert the generic linebreak behavior (for now, these are the relevant PRs: #512, #584)
4. Generate a diff between a/ (original code) and b/ (updated code)

• git diff -p a b --no-prefix > no-linebreak-generics-{version}.patch

5. Add the patch to src/main/resources/ and update the logic in PrettierArgs.java to use it as appropriate

Note

For convenience, this plugin downloads Node, prettier, and prettier-java as needed. Node is downloaded from https://nodejs.org/dist/ and prettier-plugin-java is downloaded via npm