Add kotlin and java SourceFile factories

These allow annotating the contents parameter with `@Language`, which in turn is great for consumers because IntelliJ will then apply syntax highlighting to these parameters. This also assumes they're already indented (which is necessary for the syntax highlighting), while allowing specification of is it needs to be treated as not already indented

Author: ZacSweers

src/main/kotlin/com/tschuchort/compiletesting/SourceFile.kt

@@ -2,6 +2,7 @@ package com.tschuchort.compiletesting
 
 import okio.buffer
 import okio.sink
+import org.intellij.lang.annotations.Language
 import java.io.File
 
 /**
@@ -11,6 +12,22 @@ abstract class SourceFile {
     internal abstract fun writeIfNeeded(dir: File): File
 
     companion object {
+        /**
+         * Create a new Java source file for the compilation when the compilation is run
+         */
+        fun java(name: String, @Language("java") contents: String, trimIndent: Boolean = true): SourceFile {
+            val finalContents = if (trimIndent) contents.trimIndent() else contents
+            return new(name, finalContents)
+        }
+
+        /**
+         * Create a new Kotlin source file for the compilation when the compilation is run
+         */
+        fun kotlin(name: String, @Language("kotlin") contents: String, trimIndent: Boolean = true): SourceFile {
+            val finalContents = if (trimIndent) contents.trimIndent() else contents
+            return new(name, finalContents)
+        }
+
         /**
          * Create a new source file for the compilation when the compilation is run
          */
@@ -38,4 +55,4 @@ abstract class SourceFile {
             override fun writeIfNeeded(dir: File): File = path
         }
     }
-}
+}