bugfix: walk on parameter references

The walker doesn't walk on parameter references (#/parameters/<id>) which
may contain definition references (#/definitions/<id>) that we want to
keep.

This happens often with DeleteOptions and the DeleteOptions definition
ends up being filtered out when looking at a OpenAPI V2 document.

Author: tomleb

pkg/aggregator/aggregator_test.go

@@ -45,7 +45,9 @@ func (d DebugSpec) String() string {
 }
 func TestFilterSpecs(t *testing.T) {
 	var spec1, spec1_filtered *spec.Swagger
-	yaml.Unmarshal([]byte(`
+	ast := assert.New(t)
+
+	err := yaml.Unmarshal([]byte(`
 swagger: "2.0"
 paths:
   /test:
@@ -65,6 +67,11 @@ paths:
         405:
           description: "Invalid input"
           $ref: "#/definitions/InvalidInput"
+    delete:
+      summary: "Test API Delete"
+      operationId: "deleteTest"
+      parameters:
+      - $ref: "#/parameters/body-deleteoptions"
   /othertest:
     post:
       tags:
@@ -82,6 +89,12 @@ paths:
         required: true
         schema:
           $ref: "#/definitions/Test2"
+    delete:
+      summary: "Test2 API Delete"
+      operationId: "deleteTest2"
+      parameters:
+      - schema:
+          $ref: "#/definitions/DeleteOptions"
 definitions:
   Test:
     type: "object"
@@ -102,9 +115,24 @@ definitions:
         $ref: "#/definitions/Other"
   Other:
     type: "string"
+  DeleteOptions:
+    type: "object"
+    properties:
+      preconditions:
+        $ref: "#/definitions/Preconditions"
+  Preconditions:
+    type: "string"
+parameters:
+  body-deleteoptions:
+    name: body
+    in: body
+    schema:
+      $ref: "#/definitions/DeleteOptions"
 `), &spec1)
 
-	yaml.Unmarshal([]byte(`
+	ast.NoError(err)
+
+	err = yaml.Unmarshal([]byte(`
 swagger: "2.0"
 paths:
   /test:
@@ -124,6 +152,11 @@ paths:
         405:
           description: "Invalid input"
           $ref: "#/definitions/InvalidInput"
+    delete:
+      summary: "Test API Delete"
+      operationId: "deleteTest"
+      parameters:
+      - $ref: "#/parameters/body-deleteoptions"
 definitions:
   Test:
     type: "object"
@@ -137,9 +170,22 @@ definitions:
   InvalidInput:
     type: "string"
     format: "string"
+  DeleteOptions:
+    type: "object"
+    properties:
+      preconditions:
+        $ref: "#/definitions/Preconditions"
+  Preconditions:
+    type: "string"
+parameters:
+  body-deleteoptions:
+    name: body
+    in: body
+    schema:
+      $ref: "#/definitions/DeleteOptions"
 `), &spec1_filtered)
+	ast.NoError(err)
 
-	ast := assert.New(t)
 	orig_spec1, _ := cloneSpec(spec1)
 	new_spec1 := FilterSpecByPathsWithoutSideEffects(spec1, []string{"/test"})
 	ast.Equal(DebugSpec{spec1_filtered}, DebugSpec{new_spec1})

pkg/aggregator/walker.go

@@ -48,16 +48,25 @@ func walkOnAllReferences(walkRef func(ref *spec.Ref), root *spec.Swagger) {
 		walkRef(ref)
 
 		refStr := ref.String()
-		if refStr == "" || !strings.HasPrefix(refStr, definitionPrefix) {
+		if refStr == "" {
 			return
 		}
-		defName := refStr[len(definitionPrefix):]
 
-		if _, found := root.Definitions[defName]; found && !alreadyVisited[refStr] {
-			alreadyVisited[refStr] = true
-			def := root.Definitions[defName]
-			walker.walkSchema(&def)
+		if strings.HasPrefix(refStr, parameterPrefix) {
+			paramName := refStr[len(parameterPrefix):]
+			if param, found := root.Parameters[paramName]; found {
+				walker.walkParam(param)
+			}
+		} else if strings.HasPrefix(refStr, definitionPrefix) {
+			defName := refStr[len(definitionPrefix):]
+
+			if _, found := root.Definitions[defName]; found && !alreadyVisited[refStr] {
+				alreadyVisited[refStr] = true
+				def := root.Definitions[defName]
+				walker.walkSchema(&def)
+			}
 		}
+
 	}
 	walker.Start()
 }
@@ -116,11 +125,15 @@ func (s *readonlyReferenceWalker) walkParams(params []spec.Parameter) {
 		return
 	}
 	for _, param := range params {
-		s.walkRefCallback(&param.Ref)
-		s.walkSchema(param.Schema)
-		if param.Items != nil {
-			s.walkRefCallback(&param.Items.Ref)
-		}
+		s.walkParam(param)
+	}
+}
+
+func (s *readonlyReferenceWalker) walkParam(param spec.Parameter) {
+	s.walkRefCallback(&param.Ref)
+	s.walkSchema(param.Schema)
+	if param.Items != nil {
+		s.walkRefCallback(&param.Items.Ref)
 	}
 }