feat: Set up ktfmt to format code

BUILD

@@ -2,3 +2,8 @@ alias(
     name = "bazel-diff",
     actual = "//cli:bazel-diff",
 )
+
+alias(
+    name = "format",
+    actual = "//cli:format",
+)

MODULE.bazel

@@ -4,6 +4,7 @@ module(
     compatibility_level = 0,
 )
 
+bazel_dep(name = "aspect_rules_lint", version = "1.0.2")
 bazel_dep(name = "bazel_skylib", version = "1.6.1")
 bazel_dep(name = "rules_proto", version = "6.0.0-rc2")
 bazel_dep(name = "rules_java", version = "7.6.5")
@@ -31,3 +32,6 @@ use_repo(
     maven,
     bazel_diff_maven = "bazel_diff_maven",
 )
+
+non_module_repositories = use_extension("//:extensions.bzl", "non_module_repositories")
+use_repo(non_module_repositories, "ktfmt")

WORKSPACE

@@ -64,3 +64,17 @@ maven_install(
 load("@bazel_diff_maven//:defs.bzl", "pinned_maven_install")
 
 pinned_maven_install()
+
+load("@aspect_bazel_lib//lib:repositories.bzl", "aspect_bazel_lib_dependencies")
+
+aspect_bazel_lib_dependencies()
+
+load(
+    "@aspect_rules_lint//format:repositories.bzl",
+    "fetch_ktfmt",
+    "rules_lint_dependencies",
+)
+
+rules_lint_dependencies()
+
+fetch_ktfmt()

cli/BUILD

@@ -1,3 +1,4 @@
+load("@aspect_rules_lint//format:defs.bzl", "format_multirun")
 load("@rules_java//java:defs.bzl", "java_binary")
 load("@rules_kotlin//kotlin:jvm.bzl", "kt_jvm_library", "kt_jvm_test")
 
@@ -58,7 +59,6 @@ kt_jvm_test(
     runtime_deps = [":cli-test-lib"],
 )
 
-
 kt_jvm_test(
     name = "SourceFileHasherTest",
     data = [
@@ -106,10 +106,10 @@ kt_jvm_test(
 
 kt_jvm_test(
     name = "E2ETest",
+    data = [":workspaces"],
     jvm_flags = ["-Djava.security.manager=allow"],
     test_class = "com.bazel_diff.e2e.E2ETest",
     runtime_deps = [":cli-test-lib"],
-    data = [":workspaces"],
 )
 
 kt_jvm_test(
@@ -146,3 +146,15 @@ filegroup(
         "src/test/resources/workspaces",
     ],
 )
+
+java_binary(
+    name = "ktfmt",
+    main_class = "com.facebook.ktfmt.cli.Main",
+    runtime_deps = ["@ktfmt//jar"],
+)
+
+format_multirun(
+    name = "format",
+    kotlin = ":ktfmt",
+    visibility = ["//visibility:public"],
+)

cli/src/main/kotlin/com/bazel_diff/Main.kt

@@ -1,15 +1,15 @@
 package com.bazel_diff
 
 import com.bazel_diff.cli.BazelDiff
-import picocli.CommandLine
 import kotlin.system.exitProcess
+import picocli.CommandLine
 
 class Main {
-    companion object {
-        @JvmStatic
-        fun main(args: Array<String>) {
-            val exitCode = CommandLine(BazelDiff()).execute(*args)
-            exitProcess(exitCode)
-        }
+  companion object {
+    @JvmStatic
+    fun main(args: Array<String>) {
+      val exitCode = CommandLine(BazelDiff()).execute(*args)
+      exitProcess(exitCode)
     }
+  }
 }

cli/src/main/kotlin/com/bazel_diff/bazel/BazelClient.kt

@@ -2,59 +2,65 @@ package com.bazel_diff.bazel
 
 import com.bazel_diff.log.Logger
 import com.google.devtools.build.lib.query2.proto.proto2api.Build
+import java.util.Calendar
 import org.koin.core.component.KoinComponent
 import org.koin.core.component.inject
-import java.util.Calendar
 
 class BazelClient(
-        private val useCquery: Boolean,
-        private val fineGrainedHashExternalRepos: Set<String>,
-        private val excludeExternalTargets: Boolean
+    private val useCquery: Boolean,
+    private val fineGrainedHashExternalRepos: Set<String>,
+    private val excludeExternalTargets: Boolean
 ) : KoinComponent {
-    private val logger: Logger by inject()
-    private val queryService: BazelQueryService by inject()
+  private val logger: Logger by inject()
+  private val queryService: BazelQueryService by inject()
 
-    suspend fun queryAllTargets(): List<BazelTarget> {
-        val queryEpoch = Calendar.getInstance().getTimeInMillis()
+  suspend fun queryAllTargets(): List<BazelTarget> {
+    val queryEpoch = Calendar.getInstance().getTimeInMillis()
 
-        val repoTargetsQuery = if (excludeExternalTargets) emptyList() else listOf("//external:all-targets")
-        val targets = if (useCquery) {
-            // Explicitly listing external repos here sometimes causes issues mentioned at
-            // https://bazel.build/query/cquery#recursive-target-patterns. Hence, we query all dependencies with `deps`
-            // instead. However, we still need to append all "//external:*" targets because fine-grained hash
-            // computation depends on hashing of source files in external repos as well, which is limited to repos
-            // explicitly mentioned in `fineGrainedHashExternalRepos` flag. Therefore, for any repos not mentioned there
-            // we are still relying on the repo-generation target under `//external` to compute the hash.
-            //
-            // In addition, we must include all source dependencies in this query in order for them to show up in
-            // `configuredRuleInput`. Hence, one must not filter them out with `kind(rule, deps(..))`. However, these
-            // source targets are omitted inside BazelQueryService with the custom starlark function used to print
-            // labels.
-            (queryService.query("deps(//...:all-targets)", useCquery = true) +
-                queryService.query(repoTargetsQuery.joinToString(" + ") { "'$it'" }))
-                .distinctBy { it.rule.name }
+    val repoTargetsQuery =
+        if (excludeExternalTargets) emptyList() else listOf("//external:all-targets")
+    val targets =
+        if (useCquery) {
+          // Explicitly listing external repos here sometimes causes issues mentioned at
+          // https://bazel.build/query/cquery#recursive-target-patterns. Hence, we query all
+          // dependencies with `deps`
+          // instead. However, we still need to append all "//external:*" targets because
+          // fine-grained hash
+          // computation depends on hashing of source files in external repos as well, which is
+          // limited to repos
+          // explicitly mentioned in `fineGrainedHashExternalRepos` flag. Therefore, for any repos
+          // not mentioned there
+          // we are still relying on the repo-generation target under `//external` to compute the
+          // hash.
+          //
+          // In addition, we must include all source dependencies in this query in order for them to
+          // show up in
+          // `configuredRuleInput`. Hence, one must not filter them out with `kind(rule, deps(..))`.
+          // However, these
+          // source targets are omitted inside BazelQueryService with the custom starlark function
+          // used to print
+          // labels.
+          (queryService.query("deps(//...:all-targets)", useCquery = true) +
+                  queryService.query(repoTargetsQuery.joinToString(" + ") { "'$it'" }))
+              .distinctBy { it.rule.name }
         } else {
-            val buildTargetsQuery = listOf("//...:all-targets") + fineGrainedHashExternalRepos.map { "@$it//...:all-targets" }
-            queryService.query((repoTargetsQuery + buildTargetsQuery).joinToString(" + ") { "'$it'" })
+          val buildTargetsQuery =
+              listOf("//...:all-targets") +
+                  fineGrainedHashExternalRepos.map { "@$it//...:all-targets" }
+          queryService.query((repoTargetsQuery + buildTargetsQuery).joinToString(" + ") { "'$it'" })
         }
-        val queryDuration = Calendar.getInstance().getTimeInMillis() - queryEpoch
-        logger.i { "All targets queried in $queryDuration" }
-        return targets.mapNotNull { target: Build.Target ->
-            when (target.type) {
-                Build.Target.Discriminator.RULE -> BazelTarget.Rule(target)
-                Build.Target.Discriminator.SOURCE_FILE -> BazelTarget.SourceFile(
-                    target
-                )
-
-                Build.Target.Discriminator.GENERATED_FILE -> BazelTarget.GeneratedFile(
-                    target
-                )
-
-                else -> {
-                    logger.w { "Unsupported target type in the build graph: ${target.type.name}" }
-                    null
-                }
-            }
+    val queryDuration = Calendar.getInstance().getTimeInMillis() - queryEpoch
+    logger.i { "All targets queried in $queryDuration" }
+    return targets.mapNotNull { target: Build.Target ->
+      when (target.type) {
+        Build.Target.Discriminator.RULE -> BazelTarget.Rule(target)
+        Build.Target.Discriminator.SOURCE_FILE -> BazelTarget.SourceFile(target)
+        Build.Target.Discriminator.GENERATED_FILE -> BazelTarget.GeneratedFile(target)
+        else -> {
+          logger.w { "Unsupported target type in the build graph: ${target.type.name}" }
+          null
         }
+      }
     }
+  }
 }