[SPARK-3854][BUILD] Scala style: require spaces before `{`.

## What changes were proposed in this pull request?

Since the opening curly brace, '{', has many usages as discussed in [SPARK-3854](https://issues.apache.org/jira/browse/SPARK-3854), this PR adds a ScalaStyle rule to prevent '){' pattern  for the following majority pattern and fixes the code accordingly. If we enforce this in ScalaStyle from now, it will improve the Scala code quality and reduce review time.
```
// Correct:
if (true) {
  println("Wow!")
}

// Incorrect:
if (true){
   println("Wow!")
}
```
IntelliJ also shows new warnings based on this.

## How was this patch tested?

Pass the Jenkins ScalaStyle test.

Author: Dongjoon Hyun <dongjoon@apache.org>

Closes #11637 from dongjoon-hyun/SPARK-3854.

5 files changed, 5 insertions, 5 deletions

diff --git a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
index 339e61e572..24f61992d4 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/DataFrame.scala
@@ -1147,7 +1147,7 @@ class DataFrame private[sql](
    * columns of the input row are implicitly joined with each value that is output by the function.
    *
    * {{{
-   *   df.explode("words", "word"){words: String => words.split(" ")}
+   *   df.explode("words", "word") {words: String => words.split(" ")}
    * }}}
    * @group dfops
    * @since 1.3.0
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala b/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
index dd1fbcf3c8..daddf6e0c5 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/Dataset.scala
@@ -605,7 +605,7 @@ class Dataset[T] private[sql](
    * duplicate items.  As such, it is analogous to `UNION ALL` in SQL.
    * @since 1.6.0
    */
-  def union(other: Dataset[T]): Dataset[T] = withPlan[T](other){ (left, right) =>
+  def union(other: Dataset[T]): Dataset[T] = withPlan[T](other) { (left, right) =>
     // This breaks caching, but it's usually ok because it addresses a very specific use case:
     // using union to union many files or partitions.
     CombineUnions(Union(left, right))
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/CompressionCodecs.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/CompressionCodecs.scala
index 032ba61d9d..41cff07472 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/CompressionCodecs.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/datasources/CompressionCodecs.scala
@@ -57,7 +57,7 @@ private[datasources] object CompressionCodecs {
    * `codec` should be a full class path
    */
   def setCodecConfiguration(conf: Configuration, codec: String): Unit = {
-    if (codec != null){
+    if (codec != null) {
       conf.set("mapreduce.output.fileoutputformat.compress", "true")
       conf.set("mapreduce.output.fileoutputformat.compress.type", CompressionType.BLOCK.toString)
       conf.set("mapreduce.output.fileoutputformat.compress.codec", codec)
diff --git a/sql/core/src/main/scala/org/apache/spark/sql/execution/ui/ExecutionPage.scala b/sql/core/src/main/scala/org/apache/spark/sql/execution/ui/ExecutionPage.scala
index 49915adf6c..9d3cd9bb14 100644
--- a/sql/core/src/main/scala/org/apache/spark/sql/execution/ui/ExecutionPage.scala
+++ b/sql/core/src/main/scala/org/apache/spark/sql/execution/ui/ExecutionPage.scala
@@ -114,7 +114,7 @@ private[sql] class ExecutionPage(parent: SQLTab) extends WebUIPage("execution")
         {metadata}
       </div>
       {planVisualizationResources}
-      <script>$(function(){{ renderPlanViz(); }})</script>
+      <script>$(function() {{ renderPlanViz(); }})</script>
     </div>
   }
 
diff --git a/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetIOSuite.scala b/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetIOSuite.scala
index 34e914cb1e..b7834d76cc 100644
--- a/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetIOSuite.scala
+++ b/sql/core/src/test/scala/org/apache/spark/sql/execution/datasources/parquet/ParquetIOSuite.scala
@@ -145,7 +145,7 @@ class ParquetIOSuite extends QueryTest with ParquetTest with SharedSQLContext {
       withTempPath { dir =>
         val data = makeDecimalRDD(DecimalType(precision, scale))
         data.write.parquet(dir.getCanonicalPath)
-        readParquetFile(dir.getCanonicalPath){ df => {
+        readParquetFile(dir.getCanonicalPath) { df => {
           checkAnswer(df, data.collect().toSeq)
         }}
       }