Adds scalafmt via spotless plugin

scala/.scalafmt.conf

@@ -0,0 +1,37 @@
+# tune this file as appropriate to your style!  see: https://olafurpg.github.io/scalafmt/#Configuration
+
+version = "3.7.1"
+
+runner.dialect = "scala3"
+
+maxColumn = 150
+
+continuationIndent.callSite = 2
+
+newlines {
+  sometimesBeforeColonInMethodReturnType = false
+}
+
+align {
+  arrowEnumeratorGenerator = false
+  ifWhileOpenParen = false
+  openParenCallSite = false
+  openParenDefnSite = false
+
+  tokens = ["%", "%%"]
+}
+
+docstrings.style = Asterisk
+
+rewrite {
+  rules = [SortImports, RedundantBraces]
+  redundantBraces.maxLines = 1
+}
+
+optIn {
+  breaksInsideChains = true
+}
+
+project.excludeFilters = [
+    "metals.sbt"
+]

scala/README.md

@@ -1,4 +1,21 @@
-# 🦜️🔗 LangChain4s examples
+# 🦜️🔗 LangChain4s
+
+Build the project locally, from the project root:
+
+```bash
+./gradlew build
+```
+
+## Scalafmt
+
+The Scala module uses the [spotless](https://github.com/diffplug/spotless/tree/main/plugin-gradle#scala) plugin. 
+Therefore, the previous command (`./gradlew build`) will fail in case there is any formatting issue. To apply format, you can run the following command:
+
+```bash
+./gradlew spotlessApply
+```
+
+## Examples
 
 The following use cases show in a simplified way different functionality of LangChain4s:
 

scala/build.gradle.kts

@@ -3,6 +3,7 @@
 plugins {
     scala
     alias(libs.plugins.scala.multiversion)
+    alias(libs.plugins.spotless)
 }
 
 repositories {
@@ -36,4 +37,10 @@ dependencies {
 
 tasks.withType<Test>().configureEach {
     useJUnit()
+}
+
+spotless {
+    scala {
+        scalafmt("3.7.1").configFile(".scalafmt.conf").scalaMajorVersion("2.13")
+    }
 }