Fix co-pilot comments

Signed-off-by: Ricardo Zanini <ricardozanini@gmail.com>

Author: ricardozanini

fluent/spec/src/main/java/io/serverlessworkflow/fluent/spec/InputBuilder.java

@@ -64,13 +64,35 @@ public InputBuilder from(Object object) {
   }
 
   public InputBuilder schema(Object schema) {
-    if (this.input.getSchema() == null) this.input.setSchema(new SchemaUnion());
+    if (schema == null) {
+      this.input.setSchema(null);
+      return this;
+    }
+
+    if (this.input.getSchema() == null) {
+      this.input.setSchema(new SchemaUnion());
+    } else {
+      // Clear external schema when setting inline schema
+      this.input.getSchema().setSchemaExternal(null);
+    }
+
     this.input.getSchema().setSchemaInline(new SchemaInline(schema));
     return this;
   }
 
   public InputBuilder schema(String schema) {
-    if (this.input.getSchema() == null) this.input.setSchema(new SchemaUnion());
+    if (schema == null) {
+      this.input.setSchema(null);
+      return this;
+    }
+
+    if (this.input.getSchema() == null) {
+      this.input.setSchema(new SchemaUnion());
+    } else {
+      // Clear inline schema when setting external schema
+      this.input.getSchema().setSchemaInline(null);
+    }
+
     this.input
         .getSchema()
         .setSchemaExternal(
@@ -84,7 +106,18 @@ public InputBuilder schema(String schema) {
   }
 
   public InputBuilder schemaAsJsonString(String schema) {
-    if (this.input.getSchema() == null) this.input.setSchema(new SchemaUnion());
+    if (schema == null) {
+      this.input.setSchema(null);
+      return this;
+    }
+
+    if (this.input.getSchema() == null) {
+      this.input.setSchema(new SchemaUnion());
+    } else {
+      // Clear external schema when setting inline schema
+      this.input.getSchema().setSchemaExternal(null);
+    }
+
     this.input.getSchema().setSchemaInline(new SchemaInline(schema));
     return this;
   }

fluent/spec/src/test/java/io/serverlessworkflow/fluent/spec/InputBuilderTest.java

@@ -119,8 +119,7 @@ void testFromObjectThenString() {
 
   @Test
   void testSchemaObjectThenString() {
-    // Setting schema(Object) then schema(String) sets external schema
-    // Note: SchemaUnion may keep both inline and external, last one set takes precedence
+    // Setting schema(Object) then schema(String) should clear inline and set external
     Map<String, Object> inlineSchema = Map.of("type", "object");
     String externalUri = "http://example.com/schema.json";
     Input input = new InputBuilder().schema(inlineSchema).schema(externalUri).build();
@@ -134,7 +133,7 @@ void testSchemaObjectThenString() {
 
   @Test
   void testSchemaStringThenObject() {
-    // Setting schema(String) then schema(Object) should replace external with inline
+    // Setting schema(String) then schema(Object) should clear external and set inline
     String externalUri = "http://example.com/schema.json";
     Map<String, Object> inlineSchema = Map.of("type", "object");
     Input input = new InputBuilder().schema(externalUri).schema(inlineSchema).build();
@@ -255,4 +254,50 @@ void testSchemaOnlyDoesNotRequireSetFromNull() {
     // Verify this would not cause "Both object and str are null" validation error
     // (in the actual runtime, this input would be validated without errors)
   }
+
+  @Test
+  void testFromNullClearsFrom() {
+    // Passing null to from() should clear the from field
+    Input input = new InputBuilder().from("$.data").from((String) null).build();
+
+    assertNull(input.getFrom(), "From should be cleared when passing null");
+  }
+
+  @Test
+  void testFromObjectNullClearsFrom() {
+    // Passing null object to from() should clear the from field
+    Input input = new InputBuilder().from(Map.of("key", "value")).from((Object) null).build();
+
+    assertNull(input.getFrom(), "From should be cleared when passing null object");
+  }
+
+  @Test
+  void testSchemaNullClearsSchema() {
+    // Passing null to schema(Object) should clear the schema field
+    Input input = new InputBuilder().schema(Map.of("type", "object")).schema((Object) null).build();
+
+    assertNull(input.getSchema(), "Schema should be cleared when passing null");
+  }
+
+  @Test
+  void testSchemaStringNullClearsSchema() {
+    // Passing null to schema(String) should clear the schema field
+    Input input =
+        new InputBuilder().schema("http://example.com/schema").schema((String) null).build();
+
+    assertNull(input.getSchema(), "Schema should be cleared when passing null string");
+  }
+
+  @Test
+  void testSchemaAsJsonStringNullClearsSchema() {
+    // Passing null to schemaAsJsonString should clear the schema field
+    Input input =
+        new InputBuilder()
+            .schemaAsJsonString("{\"type\":\"object\"}")
+            .schemaAsJsonString(null)
+            .build();
+
+    assertNull(
+        input.getSchema(), "Schema should be cleared when passing null to schemaAsJsonString");
+  }
 }