rewrite-maven-plugin not picking up checkstyle XML config

[BudWhiteStudying]

My goal is to bulk-refactor a project at build time, following the CheckStyle rules defined in a checkstyle.xml file.

To that end, I read the documentation at https://docs.openrewrite.org/running-recipes/popular-recipe-guides/automatically-fix-checkstyle-violations, mandating the following Maven config:

pom.xml from the documentation page

<project>
  <build>
    <plugins>
      <plugin>
        <groupId>org.openrewrite.maven</groupId>
        <artifactId>rewrite-maven-plugin</artifactId>
        <version>6.16.1</version>
        <configuration>
          <activeRecipes>
            <recipe>org.openrewrite.staticanalysis.CodeCleanup</recipe>
          </activeRecipes>
        </configuration>
        <dependencies>
          <dependency>
            <groupId>org.openrewrite.recipe</groupId>
            <artifactId>rewrite-static-analysis</artifactId>
            <version>{{VERSION_REWRITE_STATIC_ANALYSIS}}</version>
          </dependency>
        </dependencies>
      </plugin>
      <plugin>
        <groupId>org.apache.maven.plugins</groupId>
        <artifactId>maven-checkstyle-plugin</artifactId>
        <version>3.4.0</version>
        <configuration>
          <configLocation>checkstyle.xml</configLocation>
        </configuration>
      </plugin>
    </plugins>
  </build>
</project>

My own Maven config (relevant part of) is the following, which looks similar enough:

My own pom.xml

        <plugins>
            <plugin>
                <groupId>org.openrewrite.maven</groupId>
                <artifactId>rewrite-maven-plugin</artifactId>
                <version>6.17.0</version>
                <configuration>
                    <activeRecipes>
                        <recipe>org.openrewrite.staticanalysis.CodeCleanup</recipe>
                    </activeRecipes>
                </configuration>
                <dependencies>
                    <dependency>
                        <groupId>org.openrewrite.recipe</groupId>
                        <artifactId>rewrite-static-analysis</artifactId>
                        <version>2.16.0</version>
                        <scope>runtime</scope>
                    </dependency>
                </dependencies>
            </plugin>
            <plugin>
                <groupId>org.apache.maven.plugins</groupId>
                <artifactId>maven-checkstyle-plugin</artifactId>
                <version>${checkstyle.version}</version> // 3.6.0
                <executions>
                    <execution>
                        <phase>verify</phase>
                        <goals>
                            <goal>check</goal>
                        </goals>
                    </execution>
                </executions>
                <configuration>
                    <configLocation>checkstyle.xml</configLocation>
                    <consoleOutput>true</consoleOutput>
                    <failsOnError>true</failsOnError>
                    <violationSeverity>warning</violationSeverity>
                </configuration>
            </plugin>
        </plugins>

However, running mvn rewrite:dryRun seems to ignore some style issues that CheckStyle complains about, and complains about issues that CheckStyle does not complain about; in other words, it seems rewrite-maven-plugin isn't picking up the checkstyle.xml file.

Indeed, if I run mvn rewrite:discover I get

...
[INFO] 
[INFO] Active Styles:
[INFO] 
[INFO] Active Recipes:
[INFO]     org.openrewrite.staticanalysis.CodeCleanup
[INFO] 
[INFO] Found 447 available recipes and 6 available styles.
[INFO] Configured with 1 active recipes and 0 active styles.

So, no active styles.

I double-checked that, on the other hand, CheckStyle is actually running based on that file (if I alter the name of the file in the <configLocation/> property, mvn clean checkstyle:check breaks because it can't find it.

What could I be doing wrong?

Thanks in advance!

Edit: here is a small PoC of this problem.

[sambsnyd]

Hi there. We don't have recipes for every single checkstyle rule. So it may be the case that the configuration is read but a recipe does not yet exist to resolve the checkstyle complaint in question. Can you be specific about which checkstyle rules you're hoping to have automatically resolved?

[BudWhiteStudying]

Hi there. We don't have recipes for every single checkstyle rule. So it may be the case that the configuration is read but a recipe does not yet exist to resolve the checkstyle complaint in question. Can you be specific about which checkstyle rules you're hoping to have automatically resolved?

Thanks for getting back to me. I set up a small proof of concept here https://github.com/BudWhiteStudying/checkstyle-integration-poc; I am also editing the OP in order to mention it there as well.

In the PoC, if I run mvn verify CheckStyle picks up 6 style issues, based on the content of the checkstyle.xml file:

[WARNING] src/main/java/com/rewrite/example/checkstyle/integration/poc/CheckstyleIntegrationPocApplication.java:[9,1] (whitespace) FileTabCharacter: Line contains a tab character.
[WARNING] src/main/java/com/rewrite/example/checkstyle/integration/poc/CheckstyleIntegrationPocApplication.java:[9,9] (indentation) Indentation: 'method def modifier' has incorrect indentation level 8, expected level should be 2.
[WARNING] src/main/java/com/rewrite/example/checkstyle/integration/poc/CheckstyleIntegrationPocApplication.java:[10,1] (whitespace) FileTabCharacter: Line contains a tab character.
[WARNING] src/main/java/com/rewrite/example/checkstyle/integration/poc/CheckstyleIntegrationPocApplication.java:[10,17] (indentation) Indentation: 'method def' child has incorrect indentation level 16, expected level should be 4.
[WARNING] src/main/java/com/rewrite/example/checkstyle/integration/poc/CheckstyleIntegrationPocApplication.java:[11,1] (whitespace) FileTabCharacter: Line contains a tab character.
[WARNING] src/main/java/com/rewrite/example/checkstyle/integration/poc/CheckstyleIntegrationPocApplication.java:[11,9] (indentation) Indentation: 'method def rcurly' has incorrect indentation level 8, expected level should be 2

All 6 are in class CheckstyleIntegrationPocApplication; if I understand correctly they belong to rules (whitespace) FileTabCharacter and (indentation) Indentation.

If I run mvn rewrite:dryRun, instead, I get:

[INFO] Using active recipe(s) [org.openrewrite.staticanalysis.CodeCleanup]
[INFO] Using active styles(s) []
[INFO] Validating active recipes...
[INFO] Project [checkstyle-integration-poc] Resolving Poms...
[INFO] Project [checkstyle-integration-poc] Parsing source files
[INFO] Running recipe(s)...
[WARNING] These recipes would make changes to src/main/java/com/rewrite/example/checkstyle/integration/poc/model/GetAnimalsResponse.java:
[WARNING]     org.openrewrite.staticanalysis.CustomImportOrder
[WARNING] These recipes would make changes to src/main/java/com/rewrite/example/checkstyle/integration/poc/service/SampleService.java:
[WARNING]     org.openrewrite.staticanalysis.CustomImportOrder

So the OpenRewrite plugin would make changes to classes GetAnimalsResponse and SampleService, instead of targeting class CheckstyleIntegrationPocApplication like CheckStyle would.

From your reply (and the documentation) I do understand that OpenRewrite doesn't support all CheckStyle rules, and I'm ok with that; maybe the rules involved in this PoC ((whitespace) FileTabCharacter and (indentation) Indentation) are among the unsupported ones, alright.

But then I would expect the plugin to suggest no changes at all; why does it suggest changes in classes that CheckStyle doesn't pick up at all? It seems to me that the plugin is running based on a completely different set of rules, ignoring my XML file altogether, hence my doubt of having misconfigured it somehow.

Does my analysis make sense to you? Is there a way to check whether the plugin is picking up the file or not?

Thanks in advance!

[BudWhiteStudying]

After running some additional tests I realised that the plugin does pick up the checkstyle.xml file, at least at some extent.

In fact, if I change the settings of the CustomImportOrder rule that rewrite:dryRun suggests to run, for example turning separateLineBetweenGroups to false, the resulting rewrite.patch file changes!

Still, for the very same rule, the OpenRewrite plugin produces a result that doesn't match the expectations of the CheckStyle plugin; in fact, if I run rewrite:run (instead of dryRun) and then launch CheskStyle's verification again, I get 4 new warnings tied to the changes made by OpenRewrite.

Summarising:

• it seems that the OpenRewrite plugin does pick up the checkstyle.xml file (the title of this issue is therefore wrong)
• the OpenRewrite plugin isn't capable of enforcing all the rules defined within the checkstyle.xml file; this much is known and stated in the docs
• it seems that, even for those rules it does pick up (e.g. CustomImportOrder ), the OpenRewrite plugin can behave differently from what the CheckStyle plugin would expect, producing an output that doesn't pass the validation enforced by the CheckStyle plugin (this is what I had wrongly identified as OpenRewrite applying rules of its own)

Although this isn't what I had hoped for, it does answer all the questions I asked in the issue. :(