Fix handling of relative refs without leading dot

modules/swagger-parser/src/main/java/io/swagger/parser/util/SwaggerDeserializer.java

@@ -7,6 +7,7 @@
 import io.swagger.models.parameters.*;
 import io.swagger.models.properties.Property;
 import io.swagger.models.properties.PropertyBuilder;
+import io.swagger.models.properties.RefProperty;
 import io.swagger.util.Json;
 
 import java.math.BigDecimal;
@@ -424,6 +425,22 @@ public List<Parameter> parameters(ArrayNode obj, String location, ParseResult re
         return output;
     }
 
+    // Refs may need to be massaged slightly to ensure that swagger-core (specifically GenericRef) recognizes
+    // relative refs properly.  This should be done anywhere refs could appear (properties, parameters, schema, etc),
+    // so we have this function to ensure it is done consistently (and hopefully correctly) for all these occurrences.
+    //
+    // Returns a new ref string is change is needed, else returns null
+    public String mungedRef(String refString) {
+        // Ref: IETF RFC 3966, Section 5.2.2
+        if (!refString.contains(":") &&   // No scheme
+                !refString.startsWith("#") && // Path is not empty
+                !refString.startsWith("/") && // Path is not absolute
+                 refString.indexOf(".") > 0) { // Path does not start with dot but contains "." (file extension)
+            return "./" + refString;
+        }
+        return null;
+    }
+
     public Parameter parameter(ObjectNode obj, String location, ParseResult result) {
         if(obj == null) {
             return null;
@@ -433,6 +450,12 @@ public Parameter parameter(ObjectNode obj, String location, ParseResult result)
         JsonNode ref = obj.get("$ref");
         if(ref != null) {
             if(ref.getNodeType().equals(JsonNodeType.STRING)) {
+                // work-around for https://github.com/swagger-api/swagger-core/issues/2138
+                String mungedRef = mungedRef(ref.textValue());
+                if (mungedRef != null) {
+                    obj.put("$ref", mungedRef);
+                    ref = obj.get("$ref");
+                }
                 return refParameter((TextNode) ref, location, result);
             }
             else {
@@ -979,10 +1002,9 @@ public Property property(ObjectNode node, String location, ParseResult result) {
         // work-around for https://github.com/swagger-api/swagger-core/issues/1977
         if(node.get("$ref") != null && node.get("$ref").isTextual()) {
             // check if it's a relative ref
-            String refString = node.get("$ref").textValue();
-            if(refString.indexOf("/") == -1 && refString.indexOf(".") > 0) {
-                refString = "./" + refString;
-                node.put("$ref", refString);
+            String mungedRef = mungedRef(node.get("$ref").textValue());
+            if(mungedRef != null) {
+                node.put("$ref", mungedRef);
             }
         }
         return Json.mapper().convertValue(node, Property.class);
@@ -1085,7 +1107,25 @@ public Response response(ObjectNode node, String location, ParseResult result) {
 
         ObjectNode schema = getObject("schema", node, false, location, result);
         if(schema != null) {
-            output.schema(Json.mapper().convertValue(schema, Property.class));
+            JsonNode schemaRef = schema.get("$ref");
+            if (schemaRef != null) {
+                if (schemaRef.getNodeType().equals(JsonNodeType.STRING)) {
+
+                    // work-around for https://github.com/swagger-api/swagger-core/issues/2138
+                    String mungedRef = mungedRef(schemaRef.textValue());
+                    if (mungedRef != null) {
+                        schema.put("$ref", mungedRef);
+                        schemaRef = schema.get("$ref");
+                    }
+
+                    Property schemaProp = new RefProperty(schemaRef.textValue());
+                    output.schema(schemaProp);
+                } else {
+                    result.invalidType(location, "$ref", "string", node);
+                }
+            } else {
+                output.schema(Json.mapper().convertValue(schema, Property.class));
+            }
         }
         ObjectNode headersNode = getObject("headers", node, false, location, result);
         if(headersNode != null) {

modules/swagger-parser/src/test/java/io/swagger/parser/FileReferenceTests.java

@@ -1,12 +1,19 @@
 package io.swagger.parser;
 
 import io.swagger.models.*;
+
+import io.swagger.models.parameters.BodyParameter;
+import io.swagger.models.parameters.Parameter;
+import io.swagger.models.parameters.RefParameter;
 import io.swagger.models.properties.ArrayProperty;
 import io.swagger.models.properties.Property;
 import io.swagger.models.properties.RefProperty;
+import io.swagger.models.refs.RefFormat;
 import io.swagger.parser.util.SwaggerDeserializationResult;
 import org.testng.annotations.Test;
 
+import java.util.List;
+
 import static org.testng.Assert.*;
 import java.util.Arrays;
 import java.util.Map;
@@ -168,4 +175,38 @@ public void testAllOfFlatAndNested() {
             assertEquals(((RefProperty) ((ArrayProperty) props.get("siblings")).getItems()).getSimpleRef(), "pet");
         }
     }
+
+    @Test
+    public void testIssue421() {
+        SwaggerDeserializationResult result = new SwaggerParser().readWithInfo("./src/test/resources/nested-file-references/issue-421.yaml", null, true);
+        assertNotNull(result.getSwagger());
+
+        Swagger swagger = result.getSwagger();
+        assertNotNull(swagger.getPath("/pet/{petId}"));
+        assertNotNull(swagger.getPath("/pet/{petId}").getGet());
+        assertNotNull(swagger.getPath("/pet/{petId}").getGet().getParameters());
+        assertTrue(swagger.getPath("/pet/{petId}").getGet().getParameters().size() == 1);
+        assertTrue(swagger.getPath("/pet/{petId}").getGet().getParameters().get(0).getName().equals("petId"));
+        assertTrue(swagger.getDefinitions().get("Pet") instanceof ModelImpl);
+        assertTrue(swagger.getDefinitions().get("Pet").getProperties().size() == 6);
+
+        assertNotNull(swagger.getPath("/pet/{petId}").getPost());
+        assertNotNull(swagger.getPath("/pet/{petId}").getPost().getParameters());
+        assertTrue(swagger.getPath("/pet/{petId}").getPost().getParameters().size() == 3);
+        assertTrue(swagger.getPath("/pet/{petId}").getPost().getParameters().get(1) instanceof RefParameter);
+        assertTrue(((RefParameter)swagger.getPath("/pet/{petId}").getPost().getParameters().get(1)).getRefFormat() == RefFormat.INTERNAL);
+        assertTrue(((RefParameter)swagger.getPath("/pet/{petId}").getPost().getParameters().get(1)).getSimpleRef().equals("name"));
+
+        assertNotNull(swagger.getPath("/store/order"));
+        assertNotNull(swagger.getPath("/store/order").getPost());
+        assertNotNull(swagger.getPath("/store/order").getPost().getParameters());
+        assertTrue(swagger.getPath("/store/order").getPost().getParameters().size() == 1);
+        assertTrue(swagger.getPath("/store/order").getPost().getParameters().get(0) instanceof BodyParameter);
+        assertNotNull(((BodyParameter)swagger.getPath("/store/order").getPost().getParameters().get(0)).getSchema());
+        assertTrue(((BodyParameter)swagger.getPath("/store/order").getPost().getParameters().get(0)).getSchema() instanceof RefModel);
+        assertTrue(((RefModel)((BodyParameter)swagger.getPath("/store/order").getPost().getParameters().get(0)).getSchema()).getSimpleRef().equals("Order"));
+
+        assertTrue(swagger.getDefinitions().get("Order") instanceof ModelImpl);
+        assertTrue(swagger.getDefinitions().get("Order").getProperties().size() == 6);
+    }
 }

modules/swagger-parser/src/test/resources/nested-file-references/common/issue-421-defns.yaml

@@ -0,0 +1,59 @@
+definitions:
+  Pet:
+    type: object
+    required:
+      - name
+      - photoUrls
+    properties:
+      id:
+        type: integer
+        format: int64
+        x-is-unique: true
+      category:
+        $ref: '#/definitions/Category'
+      name:
+        type: string
+        example: doggie
+      photoUrls:
+        type: array
+        xml:
+          name: photoUrl
+          wrapped: true
+        items:
+          type: string
+      tags:
+        type: array
+        xml:
+          name: tag
+          wrapped: true
+        items:
+          $ref: '#/definitions/Tag'
+      status:
+        type: string
+        description: pet status in the store
+        enum:
+          - available
+          - pending
+          - sold
+    xml:
+      name: Pet
+  Category:
+    type: object
+    properties:
+      id:
+        type: integer
+        format: int64
+      name:
+        type: string
+    xml:
+      name: Category
+  Tag:
+    type: object
+    properties:
+      id:
+        type: integer
+        format: int64
+      name:
+        type: string
+    xml:
+      name: Tag

modules/swagger-parser/src/test/resources/nested-file-references/common/issue-421-parms.yaml

@@ -0,0 +1,7 @@
+petIdParam:
+  name: petId
+  in: path
+  description: ID of pet to return
+  required: true
+  type: integer
+  format: int64

modules/swagger-parser/src/test/resources/nested-file-references/issue-421.yaml

@@ -0,0 +1,100 @@
+swagger: '2.0'
+info:
+  title: Test API
+  version: '1'
+host: example.com
+basePath: /api/v1
+schemes:
+  - https
+
+paths:
+  '/pet/{petId}':
+    get:
+      tags:
+        - pet
+      summary: Find pet by ID
+      description: Returns a single pet
+      operationId: getPetById
+      produces:
+        - application/json
+      parameters:
+        - $ref: 'common/issue-421-parms.yaml#/petIdParam'
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: 'common/issue-421-defns.yaml#/definitions/Pet'
+        '400':
+          description: Invalid ID supplied
+        '404':
+          description: Pet not found
+    post:
+      tags:
+        - pet
+      summary: Updates a pet in the store with form data
+      description: ''
+      operationId: updatePetWithForm
+      consumes:
+        - application/x-www-form-urlencoded
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - $ref: 'common/issue-421-parms.yaml#/petIdParam'
+        - $ref: '#/parameters/name'
+        - $ref: '#/parameters/status'
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: '#/definitions/ApiResponse'
+        '405':
+          description: Invalid input
+  /store/order:
+    post:
+      tags:
+        - store
+      summary: Place an order for a pet
+      description: ''
+      operationId: placeOrder
+      produces:
+        - application/xml
+        - application/json
+      parameters:
+        - in: body
+          name: body
+          description: order placed for purchasing the pet
+          required: true
+          schema:
+            $ref: 'http://petstore.swagger.io/v2/swagger.json#/definitions/Order'
+      responses:
+        '200':
+          description: successful operation
+          schema:
+            $ref: 'http://petstore.swagger.io/v2/swagger.json#/definitions/Order'
+        '400':
+          description: Invalid Order
+
+parameters:
+  - name: name
+    in: formData
+    description: Updated name of the pet
+    required: false
+    type: string
+  - name: status
+    in: formData
+    description: Updated status of the pet
+    required: false
+    type: string
+
+definitions:
+  ApiResponse:
+    type: object
+    properties:
+      code:
+        type: integer
+        format: int32
+      type:
+        type: string
+      message:
+        type: string