CliOptions: turn info into a stream+writer wrapper

scalafmt-cli/src/main/scala/org/scalafmt/cli/CliOptions.scala

@@ -9,6 +9,7 @@ import org.scalafmt.sysops.OsSpecific
 
 import java.io.InputStream
 import java.io.PrintStream
+import java.io.PrintWriter
 import java.nio.file.Files
 import java.nio.file.NoSuchFileException
 import java.nio.file.Path
@@ -35,23 +36,26 @@ object CliOptions {
     * directly from main.
     */
   def auto(parsed: CliOptions): CliOptions = {
-    val usesOut = parsed.stdIn || parsed.writeMode.usesOut
-    val auxOut =
-      if (parsed.noStdErr || !usesOut) parsed.common.out else parsed.common.err
-
-    parsed.copy(common =
-      parsed.common.copy(
-        out = guardPrintStream(parsed.quiet && !usesOut)(parsed.common.out),
-        info = guardPrintStream(parsed.quiet || usesOut)(auxOut),
-        debug = guardPrintStream(parsed.quiet)(
-          if (parsed.debug) auxOut else parsed.common.debug,
-        ),
-        err = guardPrintStream(parsed.quiet)(parsed.common.err),
-      ),
+    val info: Output.StreamOrWriter =
+      if (parsed.quiet) Output.NoopStream
+      else {
+        val usesOut = parsed.stdIn || parsed.writeMode.usesOut
+        new Output.StreamOrWriter.Stream(
+          if (parsed.noStdErr || !usesOut) parsed.common.out
+          else parsed.common.err,
+        )
+      }
+    val common = parsed.common.copy(
+      out = guardPrintStream(parsed.quiet && !parsed.stdIn)(parsed.common.out),
+      info = info,
+      debug = (if (parsed.debug) info else Output.NoopStream).printWriter,
+      err = guardPrintStream(parsed.quiet)(parsed.common.err),
     )
+
+    parsed.copy(common = common)
   }
 
-  private def guardPrintStream(p: => Boolean)(
+  private def guardPrintStream(p: Boolean)(
       candidate: PrintStream,
   ): PrintStream = if (p) Output.NoopStream.printStream else candidate
 
@@ -62,8 +66,8 @@ case class CommonOptions(
     out: PrintStream = System.out,
     in: InputStream = System.in,
     err: PrintStream = System.err,
-    debug: PrintStream = Output.NoopStream.printStream,
-    info: PrintStream = Output.NoopStream.printStream,
+    debug: PrintWriter = Output.NoopStream.printWriter,
+    info: Output.StreamOrWriter = Output.NoopStream,
 ) {
   private[cli] lazy val workingDirectory: AbsoluteFile = cwd
     .getOrElse(AbsoluteFile.userDir)

scalafmt-cli/src/main/scala/org/scalafmt/cli/Output.scala

@@ -1,10 +1,33 @@
 package org.scalafmt.cli
 
 import java.io._
+import java.nio.charset._
 
 object Output {
 
-  object NoopStream extends OutputStream {
+  class WriterStream(
+      private[scalafmt] val writer: Writer,
+      charset: Charset = StandardCharsets.UTF_8,
+  ) extends OutputStream with StreamOrWriter {
+
+    override def write(b: Int): Unit = writer.write(b & 0xf)
+    override def write(b: Array[Byte]): Unit = writer
+      .write(new String(b, charset))
+    override def write(b: Array[Byte], off: Int, len: Int): Unit = writer
+      .write(new String(b, off, len, charset))
+
+    override def flush(): Unit = writer.flush()
+    override def close(): Unit = writer.close()
+
+    def outputStream: OutputStream = this
+    override def printStream: PrintStream = new PrintStream(this)
+    override def printWriter: PrintWriter = writer match {
+      case x: PrintWriter => x
+      case _ => new PrintWriter(writer)
+    }
+  }
+
+  object NoopStream extends OutputStream with StreamOrWriter {
     self =>
     override def write(b: Int): Unit = ()
 
@@ -18,4 +41,18 @@ object Output {
     val streamWriter = new OutputStreamWriter(self)
   }
 
+  trait StreamOrWriter {
+    def outputStream: OutputStream
+    def printStream: PrintStream
+    def printWriter: PrintWriter
+  }
+
+  object StreamOrWriter {
+    class Stream(val obj: PrintStream) extends StreamOrWriter {
+      override def outputStream: OutputStream = obj
+      override def printStream: PrintStream = obj
+      override def printWriter: PrintWriter = new PrintWriter(obj)
+    }
+  }
+
 }

scalafmt-cli/src/main/scala/org/scalafmt/cli/ScalafmtCliReporter.scala

@@ -41,11 +41,10 @@ class ScalafmtCliReporter(options: CliOptions) extends ScalafmtReporter {
   override def parsedConfig(config: Path, scalafmtVersion: String): Unit =
     options.common.debug.println(s"parsed config (v$scalafmtVersion): $config")
 
-  override def downloadWriter(): PrintWriter =
-    new PrintWriter(options.common.info)
+  override def downloadWriter(): PrintWriter = options.common.info.printWriter
 
   override def downloadOutputStreamWriter(): OutputStreamWriter =
-    new OutputStreamWriter(options.common.info)
+    new OutputStreamWriter(options.common.info.outputStream)
 }
 
 private class FailedToFormat(filename: String, cause: Throwable)

scalafmt-cli/src/main/scala/org/scalafmt/cli/ScalafmtRunner.scala

@@ -4,7 +4,6 @@ import org.scalafmt.Error
 import org.scalafmt.sysops.AbsoluteFile
 import org.scalafmt.sysops.BatchPathFinder
 
-import java.io.OutputStreamWriter
 import java.nio.file.Path
 
 trait ScalafmtRunner {
@@ -19,7 +18,7 @@ trait ScalafmtRunner {
       msg: String,
   ): TermDisplay = {
     val termDisplay = new TermDisplay(
-      new OutputStreamWriter(options.common.info),
+      options.common.info.printWriter,
       fallbackMode = options.nonInteractive || TermDisplay.defaultFallbackMode,
     )
     if (

scalafmt-tests/src/test/scala/org/scalafmt/cli/CliOptionsTest.scala

@@ -108,13 +108,17 @@ class CliOptionsTest extends FunSuite {
 
   test("write info to out if not writing to stdout") {
     val options = Cli.getConfig(Array.empty[String], baseCliOptionsWithOut).get
-    assertEquals(options.common.info, System.out)
+    assertEquals(options.common.info.printStream, System.out)
   }
 
   Seq("--stdin", "--stdout").foreach { arg =>
     test(s"don't write info when using $arg") {
       val options = Cli.getConfig(Array(arg), baseCliOptionsWithOut).get
-      assertEquals(options.common.info, Output.NoopStream.printStream)
+      options.common.info match {
+        case x: Output.StreamOrWriter.Stream
+            if x.obj eq Output.NoopStream.printStream =>
+        case x => fail(s"info should be writing to NoopStream: $x")
+      }
     }
   }