Exception in thread "main" java.lang.ClassNotFoundException: Failed to find data source: csv. Please find packages at http://spark.apache.org/third-party-projects.html
        at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:660)
        at org.apache.spark.sql.DataFrameReader.load(DataFrameReader.scala:194)
        at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:615)
        at org.apache.spark.sql.DataFrameReader.csv(DataFrameReader.scala:467)
        at ru.ofd.test.de.report$.process(report.scala:11)
        at ru.ofd.test.de.report$.main(report.scala:68)
        at ru.ofd.test.de.report.main(report.scala)
Caused by: java.lang.ClassNotFoundException: csv.DefaultSource
        at java.net.URLClassLoader.findClass(URLClassLoader.java:382)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:418)
        at sun.misc.Launcher$AppClassLoader.loadClass(Launcher.java:352)
        at java.lang.ClassLoader.loadClass(ClassLoader.java:351)
        at org.apache.spark.sql.execution.datasources.DataSource$.$anonfun$lookupDataSource$5(DataSource.scala:634)
        at scala.util.Try$.apply(Try.scala:213)
        at org.apache.spark.sql.execution.datasources.DataSource$.$anonfun$lookupDataSource$4(DataSource.scala:634)
        at scala.util.Failure.orElse(Try.scala:224)
        at org.apache.spark.sql.execution.datasources.DataSource$.lookupDataSource(DataSource.scala:634)
        ... 6 more

lazy val root = (project in file(".")).
  settings(
    name := "name",
    version := "1.0",
    scalaVersion := "2.12.8",
    mainClass in Compile := Some("class"),
    mainClass in assembly := Some("class")
  )

assemblyMergeStrategy in assembly := {
  case PathList("META-INF", xs@_*) => MergeStrategy.discard
  case x => MergeStrategy.first
}

val sparkVersion = "2.4.2"

libraryDependencies ++= Seq("org.apache.spark" %% "spark-sql" % sparkVersion,
  "org.apache.spark" %% "spark-core" % sparkVersion,
  "org.apache.spark" %% "spark-graphx" % sparkVersion,
  "org.xerial" % "sqlite-jdbc" % "3.32.3.2",
  "org.scala-lang" % "scala-library" % "2.12.8"
)

[IJ]assembly
[info] Strategy 'discard' was applied to 419 files (Run the task at debug level to see details)
[info] Strategy 'first' was applied to 465 files (Run the task at debug level to see details)
[success] Total time: 16 s, completed Dec 2, 2020 2:01:32 AM

assemblyMergeStrategy in assembly := {
  case "reference.conf"                       => MergeStrategy.concat
  case "application.conf"                     => MergeStrategy.concat
  case n if n.startsWith("META-INF/services") => MergeStrategy.concat
  case n
      if n.endsWith(".SF") || n.endsWith(".RSA") || n.endsWith(".DSA") || n
        .endsWith(".semanticdb") =>
    MergeStrategy.discard
  case "META-INF/MANIFEST.MF" => MergeStrategy.discard
  case _                      => MergeStrategy.first
}