Adds Spotless configuration for Java (#2485)

Author: haydenbaker

.github/workflows/ci.yml

@@ -26,7 +26,7 @@ jobs:
           distribution: 'corretto'
 
       - name: Clean, build, test, and javadoc
-        run: ./gradlew clean build javadoc -Plog-tests --stacktrace
+        run: ./gradlew clean build javadoc -PnoFormat -Plog-tests --stacktrace
 
       - name: Allow long file names in git for windows
         if: matrix.os == 'windows-latest'

buildSrc/build.gradle.kts

@@ -12,7 +12,6 @@ dependencies {
     implementation(libs.spotbugs)
     implementation(libs.spotless)
     implementation(libs.jmh)
-
     // https://github.com/gradle/gradle/issues/15383
     implementation(files(libs.javaClass.superclass.protectionDomain.codeSource.location))
 }

buildSrc/src/main/kotlin/smithy.formatting-conventions.gradle.kts

@@ -1,15 +1,33 @@
+import java.util.regex.Pattern
+
 plugins {
-    checkstyle
     id("com.diffplug.spotless")
 }
 
-// TODO: Add spotless java configuration
 /*
  * Formatting
  * ==================
  * see: https://github.com/diffplug/spotless/blob/main/plugin-gradle/README.md
  */
 spotless {
+    java {
+        // Enforce a common license header on all files
+        licenseHeaderFile("${project.rootDir}/config/spotless/license-header.txt")
+            .onlyIfContentMatches("^((?!SKIPLICENSECHECK)[\\s\\S])*\$")
+        indentWithSpaces()
+        endWithNewline()
+        eclipse().configFile("${project.rootDir}/config/spotless/formatting.xml")
+        // Fixes for some strange formatting applied by eclipse:
+        // see: https://github.com/kamkie/demo-spring-jsf/blob/bcacb9dc90273a5f8d2569470c5bf67b171c7d62/build.gradle.kts#L159
+        custom("Lambda fix") { it.replace("} )", "})").replace("} ,", "},") }
+        custom("Long literal fix") { Pattern.compile("([0-9_]+) [Ll]").matcher(it).replaceAll("\$1L") }
+        // Static first, then everything else alphabetically
+        removeUnusedImports()
+        importOrder("\\#", "")
+        // Ignore generated code for formatter check
+        targetExclude("*/build/**/*.*")
+    }
+
     // Formatting for build.gradle.kts files
     kotlinGradle {
         ktlint()
@@ -21,4 +39,12 @@ spotless {
             "import|tasks|apply|plugins|rootProject"
         )
     }
+    tasks {
+        // If the property "noFormat" is set, don't auto-format source file (like in CI)
+        if(!project.hasProperty("noFormat")) {
+            build {
+                dependsOn(spotlessApply)
+            }
+        }
+    }
 }

buildSrc/src/main/kotlin/smithy.java-conventions.gradle.kts

@@ -106,12 +106,6 @@ if (project.hasProperty("log-tests")) {
     }
 }
 
-// ==== CheckStyle ====
-// https://docs.gradle.org/current/userguide/checkstyle_plugin.html
-tasks.named("checkstyleTest") {
-    enabled = false
-}
-
 // ==== Code coverage ====
 // https://docs.gradle.org/current/userguide/jacoco_plugin.html