diff --git a/als-server/shared/src/test/resources/diagnostics/avro/async26-imports-invalid-avro.yaml b/als-server/shared/src/test/resources/diagnostics/avro/async26-imports-invalid-avro.yaml
new file mode 100644
index 000000000..8e8bb6b18
--- /dev/null
+++ b/als-server/shared/src/test/resources/diagnostics/avro/async26-imports-invalid-avro.yaml
@@ -0,0 +1,23 @@
+asyncapi: 2.6.0
+info:
+  title: Market Data API
+  version: 1.0.0
+  description: This API provides real-time market data updates.
+
+channels:
+  m1:
+    description: Pancho
+     
+components:
+  messages:
+    m1:
+      schemaFormat: application/vnd.apache.avro;version=1.9.0
+      payload:
+        $ref: schemas/union-type-invalid-payload.avsc
+      examples:
+        - payload:
+                name: John Doe
+                address: 
+                  zipcode: 1355
+                age: 20
+                favoriteProgrammingLanguage: Java
\ No newline at end of file
diff --git a/als-server/shared/src/test/resources/diagnostics/avro/async26-imports-valid-avro.yaml b/als-server/shared/src/test/resources/diagnostics/avro/async26-imports-valid-avro.yaml
new file mode 100644
index 000000000..3776f14b7
--- /dev/null
+++ b/als-server/shared/src/test/resources/diagnostics/avro/async26-imports-valid-avro.yaml
@@ -0,0 +1,15 @@
+asyncapi: 2.6.0
+info:
+  title: Market Data API
+  version: 1.0.0
+  description: This API provides real-time market data updates.
+channels:
+  m1:
+    description: Pancho
+  
+components:
+  messages:
+    m1:
+      schemaFormat: application/vnd.apache.avro;version=1.9.0
+      payload:
+        $ref: schemas/union-type-payload.avsc
\ No newline at end of file
diff --git a/als-server/shared/src/test/resources/diagnostics/avro/schemas/avro-user/avrotoavro.avsc b/als-server/shared/src/test/resources/diagnostics/avro/schemas/avro-user/avrotoavro.avsc
new file mode 100644
index 000000000..4d560fa65
--- /dev/null
+++ b/als-server/shared/src/test/resources/diagnostics/avro/schemas/avro-user/avrotoavro.avsc
@@ -0,0 +1,20 @@
+{
+	"type" : "record",
+	"name" : "avrotoavro",
+	"fields" : [
+		{"name": "user_user", "type":  {
+			"name": "user",
+			"type": "record",
+			"fields": [
+				{
+					"name": "username",
+					"type": "string"
+				},
+				{
+					"name": "age",
+					"type": "int"
+				}
+			]
+		}}
+	]
+}
\ No newline at end of file
diff --git a/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-invalid-payload.avsc b/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-invalid-payload.avsc
new file mode 100644
index 000000000..24f929f5c
--- /dev/null
+++ b/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-invalid-payload.avsc
@@ -0,0 +1,20 @@
+{
+  "type": "record",
+  "name": "Person",
+  "fields": [
+    {"name": "name", "type": "string", "example": "Donkey"},
+    {"name": "age", "type": ["null", "int"], "default": null},
+    {
+      "name": "favoriteProgrammingLanguage",
+      "type": {"name": "ProgrammingLanguage", "type": "enum", "symbols": ["JS", "Java", "Go", "Rust", "C"]}
+    },
+    {
+      "name": "address",
+      "type": {
+        "name": "Address",
+        "type": "record",
+        "fields": [{"name": "zipcode", "type": "int"}, {"name": "zipcode", "type": "boolean"}]
+      }
+    }
+  ]
+}
\ No newline at end of file
diff --git a/als-server/shared/src/test/resources/diagnostics/avro/union-type-payload-error.avsc b/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-payload-error.avsc
similarity index 100%
rename from als-server/shared/src/test/resources/diagnostics/avro/union-type-payload-error.avsc
rename to als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-payload-error.avsc
diff --git a/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-payload.avsc b/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-payload.avsc
new file mode 100644
index 000000000..07cd0fb76
--- /dev/null
+++ b/als-server/shared/src/test/resources/diagnostics/avro/schemas/union-type-payload.avsc
@@ -0,0 +1,20 @@
+{
+  "type": "record",
+  "name": "Person",
+  "fields": [
+    {"name": "name", "type": "string", "example": "Donkey"},
+    {"name": "age", "type": ["null", "int"], "default": null},
+    {
+      "name": "favoriteProgrammingLanguage",
+      "type": {"name": "ProgrammingLanguage", "type": "enum", "symbols": ["JS", "Java", "Go", "Rust", "C"]}
+    },
+    {
+      "name": "address",
+      "type": {
+        "name": "Address",
+        "type": "record",
+        "fields": [{"name": "zipcode", "type": "int"}]
+      }
+    }
+  ]
+}
\ No newline at end of file
diff --git a/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/BasicCleanDiagnosticTest.scala b/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/BasicCleanDiagnosticTest.scala
index 62e06ca4a..2535e5401 100644
--- a/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/BasicCleanDiagnosticTest.scala
+++ b/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/BasicCleanDiagnosticTest.scala
@@ -5,6 +5,7 @@ import org.mulesoft.als.server.client.scala.LanguageServerBuilder
 import org.mulesoft.als.server.modules.WorkspaceManagerFactoryBuilder
 import org.mulesoft.als.server.protocol.LanguageServer
 import org.mulesoft.als.server.{LanguageServerBaseTest, MockDiagnosticClientNotifier}
+import org.mulesoft.lsp.feature.diagnostic.DiagnosticSeverity
 
 import scala.concurrent.ExecutionContext
 
@@ -13,32 +14,6 @@ class BasicCleanDiagnosticTest extends LanguageServerBaseTest {
   override implicit def executionContext: ExecutionContext = scala.concurrent.ExecutionContext.Implicits.global
   override def rootPath: String                            = "diagnostics"
 
-  test("async 2.6 with only one error") {
-    withServer(buildServer()) { server =>
-      for {
-        d <- requestCleanDiagnostic(server)(filePath("async26/async-api26-full.yaml"))
-      } yield {
-        server.shutdown()
-        assert(d.size == 1)
-        assert(d.head.diagnostics.size == 1)
-        assert(d.head.diagnostics.head.message == "Property 'error' not supported in a ASYNC 2.6 webApi node")
-        assert(d.head.profile == ProfileNames.ASYNC26)
-      }
-    }
-  }
-
-  test("Avro with only one error") {
-    withServer(buildServer()) { server =>
-      for {
-        d <- requestCleanDiagnostic(server)(filePath("avro/union-type-payload-error.avsc"))
-      } yield {
-        server.shutdown()
-        assert(d.size == 1)
-        assert(d.head.diagnostics.isEmpty)
-        assert(d.head.profile == ProfileNames.AVROSCHEMA)
-      }
-    }
-  }
 
 
   def buildServer(): LanguageServer = {
diff --git a/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/support/async/Async26CleanDiagnosticTest.scala b/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/support/async/Async26CleanDiagnosticTest.scala
new file mode 100644
index 000000000..93efea05b
--- /dev/null
+++ b/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/support/async/Async26CleanDiagnosticTest.scala
@@ -0,0 +1,27 @@
+package org.mulesoft.als.server.modules.diagnostic.support.async
+
+import amf.core.client.common.validation.ProfileNames
+import org.mulesoft.als.server.client.scala.LanguageServerBuilder
+import org.mulesoft.als.server.modules.WorkspaceManagerFactoryBuilder
+import org.mulesoft.als.server.modules.diagnostic.BasicCleanDiagnosticTest
+import org.mulesoft.als.server.protocol.LanguageServer
+import org.mulesoft.als.server.{LanguageServerBaseTest, MockDiagnosticClientNotifier}
+
+import scala.concurrent.ExecutionContext
+
+class Async26CleanDiagnosticTest extends BasicCleanDiagnosticTest {
+
+  test("async 2.6 with only one error") {
+    withServer(buildServer()) { server =>
+      for {
+        d <- requestCleanDiagnostic(server)(filePath("async26/async-api26-full.yaml"))
+      } yield {
+        server.shutdown()
+        assert(d.size == 1)
+        assert(d.head.diagnostics.size == 1)
+        assert(d.head.diagnostics.head.message == "Property 'error' not supported in a ASYNC 2.6 webApi node")
+        assert(d.head.profile == ProfileNames.ASYNC26)
+      }
+    }
+  }
+}
diff --git a/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/support/avro/AvroCleanDiagnosticTest.scala b/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/support/avro/AvroCleanDiagnosticTest.scala
new file mode 100644
index 000000000..3352bedb5
--- /dev/null
+++ b/als-server/shared/src/test/scala/org/mulesoft/als/server/modules/diagnostic/support/avro/AvroCleanDiagnosticTest.scala
@@ -0,0 +1,67 @@
+package org.mulesoft.als.server.modules.diagnostic.support.avro
+
+import amf.core.client.common.validation.ProfileNames
+import org.mulesoft.als.server.modules.diagnostic.BasicCleanDiagnosticTest
+import org.mulesoft.lsp.feature.diagnostic.DiagnosticSeverity
+
+
+class AvroCleanDiagnosticTest extends BasicCleanDiagnosticTest {
+
+  test("Async importing valid Avro") {
+    withServer(buildServer()) { server =>
+      for {
+        d <- requestCleanDiagnostic(server)(filePath("avro/async26-imports-valid-avro.yaml"))
+      } yield {
+        server.shutdown()
+        d.foreach(filediag => assert(filediag.diagnostics.isEmpty))
+        assert(d.size == 2)
+        assert(d.head.profile == ProfileNames.ASYNC26)
+      }
+    }
+  }
+
+  test("Async importing invalid Avro") {
+    withServer(buildServer()) { server =>
+      for {
+        d <- requestCleanDiagnostic(server)(filePath("avro/async26-imports-invalid-avro.yaml"))
+      } yield {
+        server.shutdown()
+        assert(d.size == 2)
+        val avroFileDiagnostics = d.find(d => d.uri.contains("avro/async26-imports-invalid-avro.yaml"))
+        assert(avroFileDiagnostics.isDefined)
+        assert(avroFileDiagnostics.get.diagnostics.length == 1)
+        val errorMessage = avroFileDiagnostics.get.diagnostics.head.message.toLowerCase()
+        assert(errorMessage.contains("duplicate") && errorMessage.contains("address"))
+        assert(avroFileDiagnostics.get.diagnostics.head.severity.get == DiagnosticSeverity.Error)
+        assert(avroFileDiagnostics.get.profile == ProfileNames.ASYNC26)
+      }
+    }
+  }
+
+
+  test("valid complex avro") {
+    withServer(buildServer()) { server =>
+      for {
+        d <- requestCleanDiagnostic(server)(filePath("avro/schemas/avro-user/avrotoavro.avsc"))
+      } yield {
+        server.shutdown()
+        assert(d.size == 1)
+        assert(d.head.diagnostics.isEmpty)
+        assert(d.head.profile == ProfileNames.AVROSCHEMA)
+      }
+    }
+  }
+
+  test("valid avro with unions") {
+    withServer(buildServer()) { server =>
+      for {
+        d <- requestCleanDiagnostic(server)(filePath("avro/schemas/union-type-payload-error.avsc"))
+      } yield {
+        server.shutdown()
+        assert(d.size == 1)
+        assert(d.head.diagnostics.isEmpty)
+        assert(d.head.profile == ProfileNames.AVROSCHEMA)
+      }
+    }
+  }
+}