Add string helper to validate coloured column

src/test/scala/com/github/mrpowers/spark/fast/tests/DatasetComparerTest.scala

@@ -3,6 +3,7 @@ package com.github.mrpowers.spark.fast.tests
 import org.apache.spark.sql.types._
 import SparkSessionExt._
 import com.github.mrpowers.spark.fast.tests.SchemaComparer.DatasetSchemaMismatch
+import com.github.mrpowers.spark.fast.tests.StringExt.StringOps
 import org.scalatest.freespec.AnyFreeSpec
 
 object Person {
@@ -20,7 +21,26 @@ class DatasetComparerTest extends AnyFreeSpec with DatasetComparer with SparkSes
  import spark.implicits._
 
  "provides a good README example" in {
+ val sourceDS = Seq(
+ Person("juan", 5),
+ Person("bob", 1),
+ Person("li", 49),
+ Person("alice", 5)
+ ).toDS
+
+ val expectedDS = Seq(
+ Person("juan", 5),
+ Person("frank", 10),
+ Person("li", 49),
+ Person("lucy", 5)
+ ).toDS
+
+ val e = intercept[DatasetContentMismatch] {
+ assertSmallDatasetEquality(sourceDS, expectedDS)
+ }
+ }
 
+ "Correctly mark unequal column" in {
  val sourceDS = Seq(
  Person("juan", 5),
  Person("bob", 1),
@@ -39,10 +59,14 @@ class DatasetComparerTest extends AnyFreeSpec with DatasetComparer with SparkSes
  assertSmallDatasetEquality(sourceDS, expectedDS)
  }
 
+ val colourGroup = e.getMessage.extractColorGroup
+ val expectedColourGroup = colourGroup.get(Console.GREEN)
+ val actualColourGroup = colourGroup.get(Console.RED)
+ assert(expectedColourGroup.contains(Seq("[frank,10]", "lucy")))
+ assert(actualColourGroup.contains(Seq("[bob,1]", "alice")))
  }
 
  "works with really long columns" in {
-
  val sourceDS = Seq(
  Person("juanisareallygoodguythatilikealotOK", 5),
  Person("bob", 1),
@@ -60,7 +84,6 @@ class DatasetComparerTest extends AnyFreeSpec with DatasetComparer with SparkSes
  val e = intercept[DatasetContentMismatch] {
  assertSmallDatasetEquality(sourceDS, expectedDS)
  }
-
  }
 
  "does nothing if the DataFrames have the same schemas and content" in {

src/test/scala/com/github/mrpowers/spark/fast/tests/StringExt.scala

@@ -0,0 +1,15 @@
+package com.github.mrpowers.spark.fast.tests
+
+import scala.util.matching.Regex
+
+object StringExt {
+ val coloredStringPattern: Regex = "(\u001B\\[\\d{1,2}m)([\\s\\S]*?)(?=\u001B\\[\\d{1,2}m)".r
+ implicit class StringOps(s: String) {
+ def extractColorGroup: Map[String, Seq[String]] = coloredStringPattern
+ .findAllMatchIn(s)
+ .map(m => (m.group(1), m.group(2)))
+ .toSeq
+ .groupBy(_._1)
+ .mapValues(_.map(_._2))
+ }
+}