support master with no paths case

Author: tomzo

README.md

@@ -13,7 +13,7 @@ The input swagger specs must follow a convention:
 
 ## Merge specification
 
- * All input files are valid swagger files alone
+ * All input files are valid swagger files alone, except for master which may have no paths.
  * Only **paths, definitions, parameters and responses** are copied from partials.
  * If element is defined only in one partial, it is copied as is.
  * If element exists in more than one partial, then:

src/test/java/com/ai_traders/swagger/composer/ComposerTest.java

@@ -45,6 +45,24 @@ public void shouldMergeSimpleCase() throws Exception {
         assertThat(outputMerged.getConflicts().size(),is(0));
     }
 
+    InputSwaggers loadNoPathsMasterCase() throws IOException {
+        return new InputSwaggers(
+                loadSwaggerSource("noPathsMaster/master.yaml"),
+                loadSwaggerSource("noPathsMaster/part1.yaml"));
+    }
+
+    @Test
+    public void shouldNoPathsMasterCase() throws Exception {
+        InputSwaggers input = loadNoPathsMasterCase();
+        MergedSwagger outputMerged = composer.merge(input);
+        Swagger output = outputMerged.getMerged();
+        assertNull(output.getPath("/v1/products"));
+        assertNotNull(output.getPath("/v2/products"));
+        assertNotNull(output.getDefinitions().get("Product"));
+        assertNotNull(output.getDefinitions().get("Error"));
+        assertThat(outputMerged.getConflicts().size(),is(0));
+    }
+
     InputSwaggers loadBasePathCase() throws IOException {
         return new InputSwaggers(
                 loadSwaggerSource("basePath/master.yaml"),

src/test/resources/noPathsMaster/master.yaml

@@ -0,0 +1,43 @@
+# this is an example of the Uber API
+# as a demonstration of an API spec in YAML
+swagger: '2.0'
+info:
+  title: Uber API
+  description: Move your app forward with the Uber API
+  version: "1.0.0"
+# the domain of the service
+host: api.uber.com
+# array of all schemes that your API supports
+schemes:
+  - https
+produces:
+  - application/json
+definitions:
+  Product:
+    type: object
+    properties:
+      product_id:
+        type: string
+        description: Unique identifier representing a specific product for a given latitude & longitude. For example, uberX in San Francisco will have a different product_id than uberX in Los Angeles.
+      description:
+        type: string
+        description: Description of product.
+      display_name:
+        type: string
+        description: Display name of product.
+      capacity:
+        type: string
+        description: Capacity of product. For example, 4 people.
+      image:
+        type: string
+        description: Image URL representing the product.
+  Error:
+    type: object
+    properties:
+      code:
+        type: integer
+        format: int32
+      message:
+        type: string
+      fields:
+        type: string

src/test/resources/noPathsMaster/part1.yaml

@@ -0,0 +1,78 @@
+# this is an example of the Uber API
+# as a demonstration of an API spec in YAML
+swagger: '2.0'
+info:
+  title: Uber API
+  description: Move your app forward with the Uber API
+  version: "1.0.0"
+# the domain of the service
+host: api.uber.com
+# array of all schemes that your API supports
+schemes:
+  - https
+produces:
+  - application/json
+paths:
+  /v2/products:
+    get:
+      summary: Product Types
+      description: |
+        The Products endpoint returns information about the *Uber* products
+        offered at a given location. The response includes the display name
+        and other details about each product, and lists the products in the
+        proper display order.
+      parameters:
+        - name: latitude
+          in: query
+          description: Latitude component of location.
+          required: true
+          type: number
+          format: double
+        - name: longitude
+          in: query
+          description: Longitude component of location.
+          required: true
+          type: number
+          format: double
+      tags:
+        - Products
+      responses:
+        200:
+          description: An array of products
+          schema:
+            type: array
+            items:
+              $ref: '#/definitions/Product'
+        default:
+          description: Unexpected error
+          schema:
+            $ref: '#/definitions/Error'
+definitions:
+  Product:
+    type: object
+    properties:
+      product_id:
+        type: string
+        description: Unique identifier representing a specific product for a given latitude & longitude. For example, uberX in San Francisco will have a different product_id than uberX in Los Angeles.
+      description:
+        type: string
+        description: Description of product.
+      display_name:
+        type: string
+        description: Display name of product.
+      capacity:
+        type: string
+        description: Capacity of product. For example, 4 people.
+      image:
+        type: string
+        description: Image URL representing the product.
+  Error:
+    type: object
+    properties:
+      code:
+        type: integer
+        format: int32
+      message:
+        type: string
+      fields:
+        type: string