chore: remove spotless from build and docs

Signed-off-by: Gregor Zeitlinger <gregor.zeitlinger@grafana.com>

Author: zeitlinger

AGENTS.md

@@ -21,22 +21,16 @@ mise run test
 # Run all tests including integration tests
 mise run test-all
 
-# Format code with Google Java Format
-mise run format
-
 # Run a single test class
 ./mvnw test -Dtest=CounterTest \
-  -Dspotless.check.skip=true \
   -Dcoverage.skip=true -Dcheckstyle.skip=true
 
 # Run a single test method
 ./mvnw test -Dtest=CounterTest#testIncrement \
-  -Dspotless.check.skip=true \
   -Dcoverage.skip=true -Dcheckstyle.skip=true
 
 # Run tests in a specific module
 ./mvnw test -pl prometheus-metrics-core \
-  -Dspotless.check.skip=true \
   -Dcoverage.skip=true -Dcheckstyle.skip=true
 
 # Regenerate protobuf classes (after protobuf dep update)
@@ -86,7 +80,7 @@ Pre-built instrumentations:
 
 ## Code Style
 
-- **Formatter**: Google Java Format (enforced via Spotless)
+- **Formatter**: Google Java Format (enforced via flint)
 - **Line length**: 100 characters
   (enforced for ALL files including Markdown, Java, YAML)
 - **Indentation**: 2 spaces
@@ -109,7 +103,7 @@ commits. CI will fail if these checks fail.
 
 - **ALWAYS** run `mise run build` after modifying Java files
   to ensure:
-  - Code formatting (Spotless with Google Java Format)
+  - Code formatting via flint
   - Static analysis (`Error Prone` with NullAway)
   - Checkstyle validation
   - Build succeeds (tests are skipped;

CONTRIBUTING.md

@@ -43,12 +43,9 @@ git push --force-with-lease
 
 ## Formatting
 
-This repository uses [Google Java Format](https://github.com/google/google-java-format) to format
-the code.
+This repository uses flint to run formatting and lint checks.
 
-Run `./mvnw spotless:apply` to format the code (only changed files) before committing.
-
-Or run all the linters:
+Run all the linters:
 
 `mise run lint`
 
@@ -79,15 +76,14 @@ mise --cd .mise/envs/native run native-test
 
 ### Avoid failures while running tests
 
-- Use `-Dspotless.check.skip=true` to skip the formatting check during development.
 - Use `-Dcoverage.skip=true` to skip the coverage check during development.
 - Use `-Dcheckstyle.skip=true` to skip the checkstyle check during development.
 - Use `-Dwarnings=-nowarn` to skip the warnings during development.
 
 Combine all with
 
 ```shell
-./mvnw install -DskipTests -Dspotless.check.skip=true -Dcoverage.skip=true \
+./mvnw install -DskipTests -Dcoverage.skip=true \
   -Dcheckstyle.skip=true -Dwarnings=-nowarn
 ```
 

integration-tests/it-spring-boot-smoke-test/pom.xml

@@ -168,24 +168,6 @@
               <!-- editorconfig-checker-enable -->
             </configuration>
           </plugin>
-          <plugin>
-            <groupId>com.diffplug.spotless</groupId>
-            <artifactId>spotless-maven-plugin</artifactId>
-            <version>3.3.0</version>
-            <configuration>
-              <java>
-                <googleJavaFormat/>
-              </java>
-            </configuration>
-            <executions>
-              <execution>
-                <phase>verify</phase>
-                <goals>
-                  <goal>check</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
         </plugins>
       </build>
     </profile>

mise.toml

@@ -32,28 +32,22 @@ run = "./mvnw clean install"
 env.REQUIRE_PROTO_UP_TO_DATE = "true"
 env.PROTO_GENERATION = "true"
 
-[tasks.format]
-description = "format source code"
-# Use fully-qualified plugin goal and deactivate the examples-and-integration-tests
-# profile because standalone example modules don't inherit the spotless plugin.
-run = "./mvnw com.diffplug.spotless:spotless-maven-plugin:apply -P '!examples-and-integration-tests'"
-
 [tasks.clean]
 description = "clean all modules"
 run = "./mvnw clean"
 
 [tasks.compile]
 description = "bare compile, ignoring formatting and linters"
-run = "./mvnw install -DskipTests -Dspotless.check.skip=true -Dcoverage.skip=true -Dcheckstyle.skip=true -Dwarnings=-nowarn"
+run = "./mvnw install -DskipTests -Dcoverage.skip=true -Dcheckstyle.skip=true -Dwarnings=-nowarn"
 
 [tasks.generate]
 description = "regenerate protobuf sources"
-run = "./mvnw clean install -DskipTests -Dspotless.check.skip=true -Dcoverage.skip=true -Dcheckstyle.skip=true -Dwarnings=-nowarn"
+run = "./mvnw clean install -DskipTests -Dcoverage.skip=true -Dcheckstyle.skip=true -Dwarnings=-nowarn"
 env.PROTO_GENERATION = "true"
 
 [tasks.test]
 description = "run unit tests, ignoring formatting and linters"
-run = "./mvnw test -Dspotless.check.skip=true -Dcoverage.skip=true -Dcheckstyle.skip=true -Dwarnings=-nowarn"
+run = "./mvnw test -Dcoverage.skip=true -Dcheckstyle.skip=true -Dwarnings=-nowarn"
 
 [tasks.test-all]
 description = "run all tests"

pom.xml

@@ -29,7 +29,6 @@
     <jacoco.line-coverage>0.70</jacoco.line-coverage>
     <checkstyle.skip>false</checkstyle.skip>
     <coverage.skip>false</coverage.skip>
-    <spotless.skip>false</spotless.skip>
     <javadoc.skip>false</javadoc.skip>
     <warnings>-Werror</warnings>
   </properties>

prometheus-metrics-bom/pom.xml

@@ -17,10 +17,6 @@
     Bill of Materials for the Prometheus Metrics library
   </description>
 
-  <properties>
-    <spotless.skip>true</spotless.skip>
-  </properties>
-
   <dependencyManagement>
     <dependencies>
       <dependency>

prometheus-metrics-otel-support/pom.xml

@@ -21,7 +21,6 @@
   <properties>
     <checkstyle.skip>true</checkstyle.skip>
     <coverage.skip>true</coverage.skip>
-    <spotless.skip>true</spotless.skip>
     <javadoc.skip>true</javadoc.skip>
   </properties>
 

prometheus-metrics-parent/pom.xml

@@ -16,7 +16,6 @@
   <properties>
     <checkstyle.skip>true</checkstyle.skip>
     <coverage.skip>true</coverage.skip>
-    <spotless.skip>true</spotless.skip>
     <javadoc.skip>true</javadoc.skip>
   </properties>
 
@@ -70,35 +69,6 @@
   </build>
 
   <profiles>
-    <profile>
-      <id>java17-plus</id>
-      <activation>
-        <jdk>[17,)</jdk>
-      </activation>
-      <build>
-        <plugins>
-          <plugin>
-            <groupId>com.diffplug.spotless</groupId>
-            <artifactId>spotless-maven-plugin</artifactId>
-            <version>3.3.0</version>
-            <configuration>
-              <java>
-                <googleJavaFormat/>
-              </java>
-              <skip>${spotless.skip}</skip>
-            </configuration>
-            <executions>
-              <execution>
-                <phase>verify</phase>
-                <goals>
-                  <goal>check</goal>
-                </goals>
-              </execution>
-            </executions>
-          </plugin>
-        </plugins>
-      </build>
-    </profile>
     <profile>
       <id>release</id>
       <build>