fix: primitive parsing for strings as DateTimes is too greedy

src/Microsoft.OpenApi/Writers/OpenApiWriterAnyExtensions.cs

@@ -68,13 +68,13 @@ public static void WriteAny(this IOpenApiWriter writer, JsonNode node)
                     writer.WriteObject(node as JsonObject);
                     break;
                 case JsonValueKind.String: // Primitive
-                    writer.WritePrimitive(node);
+                    writer.WriteValue(node.GetValue<string>());
                     break;
                 case JsonValueKind.Number: // Primitive
-                    writer.WritePrimitive(node);
+                    writer.WriteNumber(node);
                     break;
                 case JsonValueKind.True or JsonValueKind.False: // Primitive
-                    writer.WritePrimitive(node);
+                    writer.WriteValue(node.GetValue<bool>());
                     break;
                 case JsonValueKind.Null: // null
                     writer.WriteNull();
@@ -109,43 +109,10 @@ private static void WriteObject(this IOpenApiWriter writer, JsonObject entity)
             writer.WriteEndObject();
         }
 
-        private static void WritePrimitive(this IOpenApiWriter writer, JsonNode primitive)
+        private static void WriteNumber(this IOpenApiWriter writer, JsonNode number)
         {
-            Utils.CheckArgumentNull(writer);
-
-            var valueKind = primitive.GetValueKind();
-
-            if (valueKind == JsonValueKind.String && primitive is JsonValue jsonStrValue)
+            if (number is JsonValue jsonValue)
             {
-                if (jsonStrValue.TryGetValue<DateTimeOffset>(out var dto))
-                {
-                    writer.WriteValue(dto);
-                }
-                else if (jsonStrValue.TryGetValue<DateTime>(out var dt))
-                {
-                    writer.WriteValue(dt);
-                }
-                else if (jsonStrValue.TryGetValue<string>(out var strValue))
-                {
-                    // check whether string is actual string or date time object
-                    if (DateTimeOffset.TryParse(strValue, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out var dateTimeOffset))
-                    {
-                        writer.WriteValue(dateTimeOffset);
-                    }
-                    else if (DateTime.TryParse(strValue, CultureInfo.InvariantCulture, DateTimeStyles.RoundtripKind, out var dateTime))
-                    { // order matters, DTO needs to be checked first!!!
-                        writer.WriteValue(dateTime);
-                    }
-                    else
-                    {
-                        writer.WriteValue(strValue);
-                    }
-                }
-            }
-
-            else if (valueKind == JsonValueKind.Number && primitive is JsonValue jsonValue)
-            {
-
                 if (jsonValue.TryGetValue<decimal>(out var decimalValue))
                 {
                     writer.WriteValue(decimalValue);
@@ -167,14 +134,6 @@ private static void WritePrimitive(this IOpenApiWriter writer, JsonNode primitiv
                     writer.WriteValue(intValue);
                 }
             }
-            else if (valueKind is JsonValueKind.False)
-            {
-                writer.WriteValue(false);
-            }
-            else if (valueKind is JsonValueKind.True)
-            {
-                writer.WriteValue(true);
-            }
         }
     }
 }

test/Microsoft.OpenApi.Readers.Tests/V31Tests/OpenApiSchemaTests.cs

@@ -520,5 +520,41 @@ public void ParseSchemaWithUnrecognizedKeywordsWorks()
             Assert.Equal(2, schema.UnrecognizedKeywords.Count);
         }
 
+        [Fact]
+        public void ParseSchemaExampleWithPrimitivesWorks()
+        {
+            var expected1 = @"{
+  ""type"": ""string"",
+  ""example"": ""2024-01-02""
+}";
+
+            var expected2 = @"{
+  ""type"": ""string"",
+  ""example"": ""3.14""
+}";
+            var schema = new OpenApiSchema()
+            {
+                Type = JsonSchemaType.String,
+                Example = JsonValue.Create("2024-01-02")
+            };
+
+            var schema2 = new OpenApiSchema()
+            {
+                Type = JsonSchemaType.String,
+                Example = JsonValue.Create("3.14")
+            };
+
+            var textWriter = new StringWriter();
+            var writer = new OpenApiJsonWriter(textWriter);
+            schema.SerializeAsV31(writer);
+            var actual1 = textWriter.ToString();
+            Assert.Equal(expected1.MakeLineBreaksEnvironmentNeutral(), actual1.MakeLineBreaksEnvironmentNeutral());
+
+            textWriter = new StringWriter();
+            writer = new OpenApiJsonWriter(textWriter);
+            schema2.SerializeAsV31(writer);
+            var actual2 = textWriter.ToString();
+            Assert.Equal(expected2.MakeLineBreaksEnvironmentNeutral(), actual2.MakeLineBreaksEnvironmentNeutral());
+        }
     }
 }

test/Microsoft.OpenApi.Tests/Writers/OpenApiWriterAnyExtensionsTests.cs

@@ -164,12 +164,8 @@ from shouldBeTerse in shouldProduceTerseOutputValues
         [MemberData(nameof(StringifiedDateTimes))]
         public async Task WriteOpenApiDateTimeAsJsonWorksAsync(string inputString, bool produceTerseOutput)
         {
-            // Arrange
-            var input = DateTimeOffset.Parse(inputString, CultureInfo.InvariantCulture);
-            var dateTimeValue = input;
-
-            var json = await WriteAsJsonAsync(dateTimeValue, produceTerseOutput);
-            var expectedJson = "\"" + input.ToString("o") + "\"";
+            var json = await WriteAsJsonAsync(inputString, produceTerseOutput);
+            var expectedJson = "\"" + inputString + "\"";
 
             // Assert
             Assert.Equal(expectedJson, json);