fix and test for issue#1643

Author: gracekarina

modules/swagger-parser-v3/src/main/java/io/swagger/v3/parser/util/OpenAPIDeserializer.java

@@ -139,8 +139,9 @@ public class OpenAPIDeserializer {
 	private static final String REFERENCE_SEPARATOR = "#/";
 	private Components components;
 	private final Set<String> operationIDs = new HashSet<>();
+    private List<String> internalProperties = new ArrayList();
 
-	public SwaggerParseResult deserialize(JsonNode rootNode) {
+    public SwaggerParseResult deserialize(JsonNode rootNode) {
 		return deserialize(rootNode, null);
 	}
 
@@ -184,6 +185,11 @@ public OpenAPI parseRoot(JsonNode node, ParseResult result, String path) {
 				Components components = getComponents(obj, "components", result);
 				openAPI.setComponents(components);
 				this.components = components;
+                for (String schema : internalProperties){
+                    if(components.getSchemas().get(schema) == null){
+                        result.missing("components.schemas",schema);
+                    }
+                }
 			}
 
 			obj = getObject("paths", rootNode, true, location, result);
@@ -2292,6 +2298,10 @@ public Schema getSchema(ObjectNode node, String location, ParseResult result) {
 				} else {
 					schema.set$ref(ref.asText());
 				}
+                if(schema.get$ref().startsWith("#/components/schemas")){// it's internal
+                    String refName  = schema.get$ref().substring(schema.get$ref().lastIndexOf("/")+1);
+                    internalProperties.add(refName);
+                }
 				return schema;
 			} else {
 				result.invalidType(location, "$ref", "string", node);

modules/swagger-parser-v3/src/test/java/io/swagger/v3/parser/test/OpenAPIV3ParserTest.java

@@ -85,6 +85,49 @@ public class OpenAPIV3ParserTest {
     protected int serverPort = getDynamicPort();
     protected WireMockServer wireMockServer;
 
+    @Test
+    public void testIssue1643() throws Exception{
+        ParseOptions options = new ParseOptions();
+        String issue1643 = "openapi: \"3.0.0\"\n" +
+                "info:\n" +
+                "  version: 1.0.0\n" +
+                "  title: People\n" +
+                "paths:\n" +
+                "  /person:\n" +
+                "    get:\n" +
+                "      operationId: getPerson\n" +
+                "      parameters:\n" +
+                "        - name: name\n" +
+                "          in: query\n" +
+                "          required: true\n" +
+                "          schema:\n" +
+                "            type: string\n" +
+                "      responses:\n" +
+                "        '200':\n" +
+                "          description: The person with the given name.          \n" +
+                "          content:\n" +
+                "            application/json:\n" +
+                "              schema:\n" +
+                "                $ref: '#/components/schemas/Person'\n" +
+                "components:\n" +
+                "  schemas:\n" +
+                "    Person:\n" +
+                "      required:\n" +
+                "      - name\n" +
+                "      type: object\n" +
+                "      properties:\n" +
+                "        name:\n" +
+                "          type: string\n" +
+                "        employee:\n" +
+                "          $ref: '#/components/schemas/Employee'";
+        SwaggerParseResult result = new OpenAPIV3Parser().readContents(issue1643, null, options);
+
+        Assert.assertNotNull(result);
+        Assert.assertNotNull(result.getOpenAPI());
+        assertEquals(result.getMessages().size(),1);
+        assertTrue(result.getMessages().contains("attribute components.schemas.Employee is missing"));
+    }
+
     @Test
     public void testExampleFormatByte() throws Exception{