Allow to disable Bloop file content comparison (#666)

Use --strict-bloop-json-check=false

This can potentially save several 100 ms if the Bloop files are already
on disk.

Author: alexarchambault

modules/build/src/main/scala/scala/build/Build.scala

@@ -115,6 +115,8 @@ object Build {
     def diagnostics: None.type   = None
   }
 
+  def defaultStrictBloopJsonCheck = true
+
   def updateInputs(
     inputs: Inputs,
     options: BuildOptions,
@@ -724,7 +726,10 @@ object Build {
 
     val project = value(buildProject(inputs, sources, generatedSources, options, scope, logger))
 
-    val updatedBloopConfig = project.writeBloopFile(logger)
+    val updatedBloopConfig = project.writeBloopFile(
+      options.internal.strictBloopJsonCheck.getOrElse(defaultStrictBloopJsonCheck),
+      logger
+    )
 
     if (updatedBloopConfig && os.isDir(classesDir0)) {
       logger.debug(s"Clearing $classesDir0")

modules/build/src/main/scala/scala/build/Project.scala

@@ -68,12 +68,16 @@ final case class Project(
   def bloopFile: BloopConfig.File =
     BloopConfig.File(BloopConfig.File.LatestVersion, bloopProject)
 
-  def writeBloopFile(logger: Logger): Boolean = {
-    val bloopFileContent = writeAsJsonToArray(bloopFile)(BloopCodecs.codecFile)
-    val dest             = directory / ".bloop" / s"$projectName.json"
+  def writeBloopFile(strictCheck: Boolean, logger: Logger): Boolean = {
+    lazy val bloopFileContent =
+      writeAsJsonToArray(bloopFile)(BloopCodecs.codecFile)
+    val dest = directory / ".bloop" / s"$projectName.json"
     val doWrite = !os.isFile(dest) || {
-      val currentContent = os.read.bytes(dest)
-      !Arrays.equals(currentContent, bloopFileContent)
+      strictCheck && {
+        logger.debug(s"Checking Bloop project in $dest")
+        val currentContent = os.read.bytes(dest)
+        !Arrays.equals(currentContent, bloopFileContent)
+      }
     }
     if (doWrite) {
       logger.debug(s"Writing bloop project in $dest")

modules/build/src/main/scala/scala/build/options/InternalOptions.scala

@@ -7,7 +7,8 @@ final case class InternalOptions(
   keepDiagnostics: Boolean = false,
   cache: Option[FileCache[Task]] = None,
   localRepository: Option[String] = None,
-  verbosity: Option[Int] = None
+  verbosity: Option[Int] = None,
+  strictBloopJsonCheck: Option[Boolean] = None
 )
 
 object InternalOptions {

modules/cli/src/main/scala/scala/cli/commands/SharedOptions.scala

@@ -101,7 +101,10 @@ final case class SharedOptions(
   @Hidden
     forbid: List[String] = Nil,
   @Recurse
-  helpGroups: HelpGroupOptions = HelpGroupOptions()
+  helpGroups: HelpGroupOptions = HelpGroupOptions(),
+
+  @Hidden
+    strictBloopJsonCheck: Option[Boolean] = None
 ) {
   // format: on
 
@@ -171,7 +174,8 @@ final case class SharedOptions(
       internal = bo.InternalOptions(
         cache = Some(coursierCache),
         localRepository = LocalRepo.localRepo(directories.directories.localRepoDir),
-        verbosity = Some(logging.verbosity)
+        verbosity = Some(logging.verbosity),
+        strictBloopJsonCheck = strictBloopJsonCheck
       )
     )
   }

website/docs/reference/cli-options.md

@@ -1043,6 +1043,8 @@ Generate SemanticDBs
 
 #### `--forbid`
 
+#### `--strict-bloop-json-check`
+
 ## Test options
 
 Available in commands: