Contains in order more details draft (#43) (#3907)

fix the following bug - the test below was passing:
```
 "fail to detect count mismatch" {
            sequenceOf("apple", "apple", "orange") should containAllInAnyOrder(
                sequenceOf("apple", "orange", "orange")
            )
        }
```
* also fix two tests named "for subset, same count with nulls" - they
were not validating correct behavior.
* also provide more details about what exactly did not match, such as:
```
Sequence should contain the values of [1, 1, 2] in any order, but was [1, 2, 2].
Count Mismatches: 
  For 1: expected count: <2>, but was: <1>
  For 2: expected count: <1>, but was: <2>
```

kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/matchers/sequences/UnorderedCollectionsDifference.kt

@@ -0,0 +1,66 @@
+package io.kotest.matchers.sequences
+
+import io.kotest.assertions.print.print
+
+internal data class UnorderedCollectionsDifference<T>(
+   val missingElements: Set<T>,
+   val extraElements: Set<T>,
+   val countMismatches: List<CountMismatch<T>>
+) {
+   private val describedMismatches = sequenceOf(
+      DescribedMismatch(missingElements, "Missing Elements"),
+      DescribedMismatch(extraElements, "Extra Elements"),
+      DescribedMismatch(countMismatches, "Count Mismatches")
+   )
+
+   fun isMatch(): Boolean {
+      return describedMismatches.all { it.elements.isEmpty() }
+   }
+
+   override fun toString(): String {
+      return if (isMatch()) "" else "\n" + describedMismatches
+         .map { it.toString() }
+         .filter { it.isNotEmpty() }
+         .joinToString("\n")
+   }
+
+   private data class DescribedMismatch<T>(
+      val elements: Collection<T>,
+      val description: String
+   ) {
+      override fun toString(): String {
+         return if (elements.isEmpty()) "" else
+             "$description:\n${elements.joinToString("\n") { it.print().value }}"
+      }
+   }
+
+   companion object {
+      fun<T> of(expected: List<T>, value: List<T>): UnorderedCollectionsDifference<T> {
+         val expectedCounts = expected.counted()
+         val valueCounts = value.counted()
+         return UnorderedCollectionsDifference(
+             missingElements = expectedCounts.keys - valueCounts.keys,
+             extraElements = valueCounts.keys - expectedCounts.keys,
+             countMismatches = expectedCounts.mapNotNull { expected ->
+                 val valueCount = valueCounts[expected.key]
+                 valueCount?.let {
+                     if (expected.value == valueCount) null else
+                         CountMismatch(expected.key, expected.value, valueCount)
+                 }
+             }
+         )
+      }
+   }
+
+   internal data class CountMismatch<T>(
+      val value: T,
+      val expectedCount: Int,
+      val actualCount: Int
+   ) {
+      init {
+         require(expectedCount != actualCount) { "Expected count should be different from actual, but both were: $expectedCount" }
+      }
+
+      override fun toString(): String = "  For ${value.print().value}: expected count: <$expectedCount>, but was: <$actualCount>"
+   }
+}

kotest-assertions/kotest-assertions-core/src/commonMain/kotlin/io/kotest/matchers/sequences/matchers.kt

@@ -168,14 +168,16 @@ fun <T> containAllInAnyOrder(vararg expected: T): Matcher<Sequence<T>?> =
 fun <T, C : Sequence<T>> containAllInAnyOrder(expected: C): Matcher<C?> = neverNullMatcher { value ->
    val valueAsList = value.toList()
    val expectedAsList = expected.toList()
-   val passed = valueAsList.size == expectedAsList.size && valueAsList.containsAll(expectedAsList)
+   val comparison = UnorderedCollectionsDifference.of(expectedAsList, valueAsList)
    MatcherResult(
-      passed,
-      { "Sequence should contain the values of $expectedAsList in any order, but was $valueAsList" },
+      comparison.isMatch(),
+      { "Sequence should contain the values of $expectedAsList in any order, but was $valueAsList.${comparison}" },
       { "Sequence should not contain the values of $expectedAsList in any order" }
    )
 }
 
+internal fun<T> List<T>.counted(): Map<T, Int> = this.groupingBy { it }.eachCount()
+
 infix fun <T : Comparable<T>, C : Sequence<T>> C.shouldHaveUpperBound(t: T) = this should haveUpperBound(t)
 
 fun <T : Comparable<T>, C : Sequence<T>> haveUpperBound(t: T) = object : Matcher<C> {

kotest-assertions/kotest-assertions-core/src/jvmTest/kotlin/com/sksamuel/kotest/matchers/collections/SequenceMatchersTest.kt

@@ -716,7 +716,7 @@ class SequenceMatchersTest : WordSpec() {
             sampleData.countup.shouldContainAllInAnyOrder((5..15).asSequence())
          }
 
-         succeed("for subset, same count with nulls") {
+         fail("for subset, same count with nulls") {
             sampleData.sparse.shouldContainAllInAnyOrder(sampleData.nulls)
          }
 
@@ -735,6 +735,17 @@ class SequenceMatchersTest : WordSpec() {
          fail("for same, different count") {
             sampleData.repeating.shouldContainAllInAnyOrder(sampleData.unique)
          }
+
+         succeed("detect different count of individual elements in collections of same length") {
+            shouldThrowAny{
+               sequenceOf(1, 2, 2).shouldContainAllInAnyOrder(sequenceOf(1, 1, 2))
+            }.shouldHaveMessage("""
+            |Sequence should contain the values of [1, 1, 2] in any order, but was [1, 2, 2].
+            |Count Mismatches:
+            |  For 1: expected count: <2>, but was: <1>
+            |  For 2: expected count: <1>, but was: <2>
+            """.trimMargin())
+         }
       }
 
       "not contain in any order" should {
@@ -754,7 +765,7 @@ class SequenceMatchersTest : WordSpec() {
             sampleData.countup.shouldNotContainAllInAnyOrder((5..15).asSequence())
          }
 
-         fail("for subset, same count with nulls") {
+         succeed("for subset, same count with nulls") {
             sampleData.sparse.shouldNotContainAllInAnyOrder(sampleData.nulls)
          }
 
@@ -774,6 +785,9 @@ class SequenceMatchersTest : WordSpec() {
             sampleData.repeating.shouldNotContainAllInAnyOrder(sampleData.unique)
          }
 
+         succeed("detect different count of individual elements in sequences of same length") {
+            sequenceOf(1, 2, 2).shouldNotContainAllInAnyOrder(sequenceOf(1, 1, 2))
+         }
       }
 
       "contain in order" should {

kotest-assertions/kotest-assertions-core/src/jvmTest/kotlin/com/sksamuel/kotest/matchers/sequences/UnorderedCollectionsDifferenceTest.kt

@@ -0,0 +1,52 @@
+package com.sksamuel.kotest.matchers.sequences
+
+import io.kotest.core.spec.style.StringSpec
+import io.kotest.matchers.sequences.UnorderedCollectionsDifference
+import io.kotest.matchers.shouldBe
+
+class UnorderedCollectionsDifferenceTest: StringSpec() {
+   init {
+      "detect match" {
+         UnorderedCollectionsDifference.of(
+            expected = listOf("apple", "orange", "apple"),
+            value = listOf("apple", "apple", "orange"),
+         ).isMatch() shouldBe true
+      }
+      "detect missing elements" {
+         UnorderedCollectionsDifference.of(
+            expected = listOf("apple", "orange", "apple", "banana"),
+            value = listOf("apple", "apple", "orange"),
+         ) shouldBe UnorderedCollectionsDifference(
+            missingElements = setOf("banana"),
+            extraElements = setOf(),
+            countMismatches = listOf()
+         )
+      }
+      "detect extra elements" {
+         UnorderedCollectionsDifference.of(
+            expected = listOf("apple", "orange", "apple"),
+            value = listOf("apple", "apple", "orange", "banana"),
+         ) shouldBe UnorderedCollectionsDifference(
+            missingElements = setOf(),
+            extraElements = setOf("banana"),
+            countMismatches = listOf()
+         )
+      }
+      "detect count mismatch" {
+         UnorderedCollectionsDifference.of(
+            expected = listOf("apple", "orange", "apple"),
+            value = listOf("apple", "apple", "orange", "orange"),
+         ) shouldBe UnorderedCollectionsDifference(
+            missingElements = setOf(),
+            extraElements = setOf(),
+            countMismatches = listOf(
+               UnorderedCollectionsDifference.CountMismatch(
+                  value = "orange",
+                  expectedCount = 1,
+                  actualCount = 2
+               )
+            )
+         )
+      }
+   }
+}