Add flag to disable blank lines between configurations

app/src/main/kotlin/com/squareup/sort/SortCommand.kt

@@ -50,6 +50,11 @@ class SortCommand(
     help = "Flag to control whether file tree walking looks in build and hidden directories. True by default.",
   ).flag("--no-skip-hidden-and-build-dirs", default = true)
 
+  private val noBlankLines by option(
+    "--no-blank-lines",
+    help = "When enabled, blank lines will not be inserted between different dependency configurations. False by default",
+  ).flag(default = false)
+
   val mode by option("-m", "--mode", help = "Mode: [sort, check]. Defaults to 'sort'. Check will report if a file is already sorted")
     .enum<Mode>().default(Mode.SORT)
 
@@ -100,9 +105,11 @@ class SortCommand(
     var successCount = 0
     var parseErrorCount = 0
     var alreadySortedCount = 0
+    val insertBlankLines = !noBlankLines
+
     filesToSort.parallelStream().forEach { file ->
       try {
-        val newContent = Sorter.sorterFor(file).rewritten()
+        val newContent = Sorter.sorterFor(file, insertBlankLines).rewritten()
         file.writeText(newContent, Charsets.UTF_8, StandardOpenOption.TRUNCATE_EXISTING)
         logger.trace("Successfully sorted: ${file.pathString} ")
         successCount++
@@ -141,6 +148,7 @@ class SortCommand(
     val notSorted = mutableListOf<Path>()
     var parseErrorCount = 0
     var alreadySortedCount = 0
+    val insertBlankLines = !noBlankLines
 
     filesToSort.parallelStream().forEach { file ->
       try {

sort-dependencies-gradle-plugin/src/main/kotlin/com/squareup/sort/SortDependenciesExtension.kt

@@ -28,6 +28,14 @@ abstract class SortDependenciesExtension @Inject constructor(
         ?: error("Can't find '$VERSION_FILENAME'")
     )
 
+  /**
+   * When true, a blank line will be inserted between dependencies of different configurations
+   * (`api`, `implementation`, etc.). Enabled by default.
+   */
+  val insertBlankLines: Property<Boolean> = objects
+    .property(Boolean::class.java)
+    .convention(true)
+
   internal val check: Property<Boolean> = objects.property(Boolean::class.java).convention(true)
 
   fun check(shouldCheck: Boolean) {

sort-dependencies-gradle-plugin/src/main/kotlin/com/squareup/sort/SortDependenciesPlugin.kt

@@ -24,10 +24,10 @@ class SortDependenciesPlugin : Plugin<Project> {
     }
 
     tasks.register("sortDependencies", SortDependenciesTask::class.java) { t ->
-      t.configure("sort", target, sortApp)
+      t.configure("sort", target, sortApp, extension)
     }
     val checkTask = tasks.register("checkSortDependencies", SortDependenciesTask::class.java) { t ->
-      t.configure("check", target, sortApp)
+      t.configure("check", target, sortApp, extension)
     }
 
     afterEvaluate {
@@ -45,10 +45,12 @@ class SortDependenciesPlugin : Plugin<Project> {
   private fun SortDependenciesTask.configure(
     mode: String,
     project: Project,
-    sortApp: Configuration
+    sortApp: Configuration,
+    extension: SortDependenciesExtension,
   ) {
     buildScript.set(project.buildFile)
     sortProgram.setFrom(sortApp)
     this.mode.set(mode)
+    insertBlankLines.set(extension.insertBlankLines)
   }
 }

sort-dependencies-gradle-plugin/src/main/kotlin/com/squareup/sort/SortDependenciesTask.kt

@@ -45,11 +45,16 @@ abstract class SortDependenciesTask @Inject constructor(
   @get:Input
   abstract val verbose: Property<Boolean>
 
+  @get:Optional
+  @get:Input
+  abstract val insertBlankLines: Property<Boolean>
+
   @TaskAction
   fun action() {
     val buildScript = buildScript.get().asFile.absolutePath
     val mode = mode.getOrElse("sort")
     val verbose = verbose.getOrElse(false)
+    val insertBlankLines = insertBlankLines.getOrElse(true)
 
     if (mode != "check" && mode != "sort") {
       throw InvalidUserDataException("Mode must be 'sort' or 'check'. Was '$mode'.")
@@ -65,9 +70,8 @@ abstract class SortDependenciesTask @Inject constructor(
           add(buildScript)
           add("--mode")
           add(mode)
-          if (verbose) {
-            add("--verbose")
-          }
+          if (verbose) add("--verbose")
+          if (!insertBlankLines) add("--no-blank-lines")
         }
       }
     }

sort-dependencies-gradle-plugin/src/test/groovy/com/squareup/sort/FunctionalSpec.groovy

@@ -224,6 +224,108 @@ final class FunctionalSpec extends Specification {
     build(dir, 'sortDependencies', '--verbose')
   }
 
+  def "no blank lines between different configurations when flag is disabled"() {
+    given: 'A build script with unsorted dependencies and multiple configurations'
+    def buildScript = dir.resolve('build.gradle.kts')
+    Files.writeString(buildScript,
+      """\
+        plugins {
+          `java-library`
+          id("com.squareup.sort-dependencies")
+        }
+
+        sortDependencies {
+          insertBlankLines = false
+        }
+
+        repositories {
+          mavenCentral()
+          maven { url = uri("$REPO") }
+        }
+
+        dependencies {
+          implementation("com.squareup.okio:okio:3.2.0")
+          api("com.squareup.okhttp3:okhttp:4.10.0")
+          testImplementation(platform("com.squareup.okhttp3:okhttp-bom:4.10.0"))
+        }
+      """.stripIndent()
+    )
+
+    when: 'We sort dependencies in the build folder'
+    build(dir, 'sortDependencies')
+
+    then: 'The build script is sorted with no blank lines between api and implementation'
+    buildScript.text == """\
+      plugins {
+        `java-library`
+        id("com.squareup.sort-dependencies")
+      }
+
+      sortDependencies {
+        insertBlankLines = false
+      }
+
+      repositories {
+        mavenCentral()
+        maven { url = uri("$REPO") }
+      }
+
+      dependencies {
+        api("com.squareup.okhttp3:okhttp:4.10.0")
+        implementation("com.squareup.okio:okio:3.2.0")
+        testImplementation(platform("com.squareup.okhttp3:okhttp-bom:4.10.0"))
+      }
+    """.stripIndent()
+  }
+
+  def "insert blank lines between different configurations when flag is omitted"() {
+    given: 'A build script with unsorted dependencies and multiple configurations'
+    def buildScript = dir.resolve('build.gradle.kts')
+    Files.writeString(buildScript,
+      """\
+        plugins {
+          `java-library`
+          id("com.squareup.sort-dependencies")
+        }
+
+        repositories {
+          mavenCentral()
+          maven { url = uri("$REPO") }
+        }
+
+        dependencies {
+          implementation("com.squareup.okio:okio:3.2.0")
+          api("com.squareup.okhttp3:okhttp:4.10.0")
+          testImplementation(platform("com.squareup.okhttp3:okhttp-bom:4.10.0"))
+        }
+      """.stripIndent()
+    )
+
+    when: 'We sort dependencies in the build folder'
+    build(dir, 'sortDependencies')
+
+    then: 'The build script is sorted with a blank line between api and implementation'
+    buildScript.text == """\
+      plugins {
+        `java-library`
+        id("com.squareup.sort-dependencies")
+      }
+
+      repositories {
+        mavenCentral()
+        maven { url = uri("$REPO") }
+      }
+
+      dependencies {
+        api("com.squareup.okhttp3:okhttp:4.10.0")
+
+        implementation("com.squareup.okio:okio:3.2.0")
+
+        testImplementation(platform("com.squareup.okhttp3:okhttp-bom:4.10.0"))
+      }
+    """.stripIndent()
+  }
+
   private static final BUILD_SCRIPT = """\
     plugins {
       id 'java-library'

sort/src/main/kotlin/com/squareup/sort/Sorter.kt

@@ -27,6 +27,7 @@ public class Sorter private constructor(
   private val rewriter: TokenStreamRewriter,
   private val errorListener: RewriterErrorListener,
   private val filePath: String,
+  private val insertBlankLines: Boolean,
 ) : GradleScriptBaseListener() {
 
   // We use a default of two spaces, but update it at most once later on.
@@ -130,7 +131,9 @@ public class Sorter private constructor(
     appendLine("dependencies {")
     dependenciesByConfiguration.entries.sortedWith(ConfigurationComparator)
       .forEachIndexed { i, entry ->
-        if (i != 0) appendLine()
+        // Place a blank line between chunks of the same configuration, if configured
+        if (i != 0 && insertBlankLines) appendLine()
+
         entry.value.sortedWith(dependencyComparator)
           .map { dependency ->
             dependency to Texts(
@@ -165,7 +168,10 @@ public class Sorter private constructor(
 
   public companion object {
     @JvmStatic
-    public fun sorterFor(file: Path): Sorter {
+    public fun sorterFor(file: Path): Sorter = sorterFor(file, insertBlankLines = true)
+
+    @JvmStatic
+    public fun sorterFor(file: Path, insertBlankLines: Boolean): Sorter {
       val input = Files.newInputStream(file, StandardOpenOption.READ).use {
         CharStreams.fromStream(it)
       }
@@ -186,7 +192,8 @@ public class Sorter private constructor(
         tokens = tokens,
         rewriter = TokenStreamRewriter(tokens),
         errorListener = errorListener,
-        filePath = file.absolutePathString()
+        filePath = file.absolutePathString(),
+        insertBlankLines = insertBlankLines,
       )
       val tree = parser.script()
       walker.walk(listener, tree)

sort/src/test/groovy/com/squareup/sort/SorterSpec.groovy

@@ -438,6 +438,41 @@ final class SorterSpec extends Specification {
     )).inOrder()
   }
 
+  def "sort without inserting newlines between different configurations"() {
+    given:
+    def buildScript = dir.resolve('build.gradle')
+    Files.writeString(buildScript,
+            '''\
+          dependencies {
+            implementation(projects.foo)
+            implementation(projects.bar)
+            implementation(projects.foo)
+
+            api(projects.foo)
+            api(projects.bar)
+            api(projects.foo)
+          }
+        '''.stripIndent())
+
+    when:
+    def newScript = Sorter.sorterFor(buildScript, false).rewritten()
+
+    then:
+    notThrown(BuildScriptParseException)
+
+    and:
+    assertThat(trimmedLinesOf(newScript)).containsExactlyElementsIn(trimmedLinesOf(
+            '''\
+          dependencies {
+            api(projects.bar)
+            api(projects.foo)
+            implementation(projects.bar)
+            implementation(projects.foo)
+          }
+        '''.stripIndent()
+    )).inOrder()
+  }
+
     def "sort add function call in dependencies"() {
     given:
     def buildScript = dir.resolve('build.gradle')