Adjusting error message to correctly state missing/extra keys (#3267)

* Adjusting error message to correctly state missing/extra keys

* Remove redundant test

kotest-assertions/kotest-assertions-json/src/commonMain/kotlin/io/kotest/assertions/json/compare.kt

@@ -201,17 +201,17 @@ internal fun compareObjects(
 ): JsonError? {
 
    if (FieldComparison.Strict == options.fieldComparison) {
-      val keys1 = expected.elements.keys
-      val keys2 = actual.elements.keys
+      val expectedKeys = expected.elements.keys
+      val actualKeys = actual.elements.keys
 
-      if (keys1.size < keys2.size) {
-         val missing = keys2 - keys1
-         return JsonError.ObjectMissingKeys(path, missing)
+      if (actualKeys.size > expectedKeys.size) {
+         val extra = actualKeys - expectedKeys
+         return JsonError.ObjectExtraKeys(path, extra)
       }
 
-      if (keys2.size < keys1.size) {
-         val extra = keys1 - keys2
-         return JsonError.ObjectExtraKeys(path, extra)
+      if (actualKeys.size < expectedKeys.size) {
+         val missing = expectedKeys - actualKeys
+         return JsonError.ObjectMissingKeys(path, missing)
       }
    }
 

kotest-assertions/kotest-assertions-json/src/jvmTest/kotlin/com/sksamuel/kotest/tests/json/EqualTest.kt

@@ -161,12 +161,12 @@ expected:<{
       }
 
       test("comparing object with extra key") {
-         val a = """ { "a" : "foo", "b" : "bar", "c": "baz" } """
-         val b = """ { "a" : "foo", "b" : "bar" } """
+         val actual = """ { "a" : "foo", "b" : "bar", "c": "baz" } """
+         val expected = """ { "a" : "foo", "b" : "bar" } """
          shouldFail {
-            a shouldEqualJson b
+            actual shouldEqualJson expected
          }.shouldHaveMessage(
-            """The top level object was missing expected field(s) [c]
+            """The top level object has extra field(s) [c]
 
 expected:<{
   "a": "foo",
@@ -180,12 +180,12 @@ expected:<{
       }
 
       test("comparing object with extra keys") {
-         val a = """ { "a" : "foo", "b" : "bar", "c": "baz", "d": true } """
-         val b = """ { "a" : "foo", "b" : "bar" } """
+         val actual = """ { "a" : "foo", "b" : "bar", "c": "baz", "d": true } """
+         val expected = """ { "a" : "foo", "b" : "bar" } """
          shouldFail {
-            a shouldEqualJson b
+            actual shouldEqualJson expected
          }.shouldHaveMessage(
-            """The top level object was missing expected field(s) [c,d]
+            """The top level object has extra field(s) [c,d]
 
 expected:<{
   "a": "foo",
@@ -200,12 +200,12 @@ expected:<{
       }
 
       test("comparing object with missing key") {
-         val a = """ { "a" : "foo", "b" : "bar" } """
-         val b = """ { "a" : "foo", "b" : "bar", "c": "baz" } """
+         val actual = """ { "a" : "foo", "b" : "bar" } """
+         val expected = """ { "a" : "foo", "b" : "bar", "c": "baz" } """
          shouldFail {
-            a shouldEqualJson b
+            actual shouldEqualJson expected
          }.shouldHaveMessage(
-            """The top level object has extra field(s) [c]
+            """The top level object was missing expected field(s) [c]
 
 expected:<{
   "a": "foo",
@@ -219,12 +219,12 @@ expected:<{
       }
 
       test("comparing object with missing keys") {
-         val a = """ { "a" : "foo", "b" : "bar" } """
-         val b = """ { "a" : "foo", "b" : "bar", "c": "baz", "d": 123 } """
+         val actual = """ { "a" : "foo", "b" : "bar" } """
+         val expected = """ { "a" : "foo", "b" : "bar", "c": "baz", "d": 123 } """
          shouldFail {
-            a shouldEqualJson b
+            actual shouldEqualJson expected
          }.shouldHaveMessage(
-            """The top level object has extra field(s) [c,d]
+            """The top level object was missing expected field(s) [c,d]
 
 expected:<{
   "a": "foo",
@@ -674,12 +674,12 @@ expected:<{
       }
 
       test("real world json without field") {
-         val a = this::class.java.getResourceAsStream("/shopify.json").bufferedReader().readText()
-         val b = this::class.java.getResourceAsStream("/shopify_without_field.json").bufferedReader().readText()
+         val actual = this::class.java.getResourceAsStream("/shopify.json").bufferedReader().readText()
+         val expected = this::class.java.getResourceAsStream("/shopify_without_field.json").bufferedReader().readText()
          shouldFail {
-            a shouldEqualJson b
+            actual shouldEqualJson expected
          }.message.shouldStartWith(
-            """At 'products.[0].variants.[0]' object was missing expected field(s) [sku]
+            """At 'products.[0].variants.[0]' object has extra field(s) [sku]
 
 expected:<{
   "products": [