add example usage of request validation with gorilla/mux router (#359)

Signed-off-by: Pierre Fenoll <pierrefenoll@gmail.com>

openapi3filter/testdata/petstore.yaml

@@ -0,0 +1,100 @@
+openapi: "3.0.0"
+info:
+  description: "This is a sample server Petstore server.  You can find out more about     Swagger at [http://swagger.io](http://swagger.io) or on [irc.freenode.net, #swagger](http://swagger.io/irc/).      For this sample, you can use the api key `special-key` to test the authorization     filters."
+  version: "1.0.0"
+  title: "Swagger Petstore"
+  termsOfService: "http://swagger.io/terms/"
+  contact:
+    email: "apiteam@swagger.io"
+  license:
+    name: "Apache 2.0"
+    url: "http://www.apache.org/licenses/LICENSE-2.0.html"
+tags:
+- name: "pet"
+  description: "Everything about your Pets"
+  externalDocs:
+    description: "Find out more"
+    url: "http://swagger.io"
+- name: "store"
+  description: "Access to Petstore orders"
+- name: "user"
+  description: "Operations about user"
+  externalDocs:
+    description: "Find out more about our store"
+    url: "http://swagger.io"
+paths:
+  /pet:
+    post:
+      tags:
+      - "pet"
+      summary: "Add a new pet to the store"
+      description: ""
+      operationId: "addPet"
+      requestBody:
+        required: true
+        content: 
+          'application/json':
+            schema:
+              $ref: '#/components/schemas/Pet'
+      responses:
+        "405":
+          description: "Invalid input"
+components:
+  schemas:
+    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"
+    Pet:
+      type: "object"
+      required:
+      - "name"
+      - "photoUrls"
+      properties:
+        id:
+          type: "integer"
+          format: "int64"
+        category:
+          $ref: "#/components/schemas/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: "#/components/schemas/Tag"
+        status:
+          type: "string"
+          description: "pet status in the store"
+          enum:
+          - "available"
+          - "pending"
+          - "sold"
+      xml:
+        name: "Pet"

openapi3filter/unpack_errors_test.go

@@ -0,0 +1,173 @@
+package openapi3filter_test
+
+import (
+	"fmt"
+	"net/http"
+	"net/http/httptest"
+	"sort"
+	"strings"
+
+	"github.com/getkin/kin-openapi/openapi3"
+	"github.com/getkin/kin-openapi/openapi3filter"
+	"github.com/getkin/kin-openapi/routers/gorillamux"
+)
+
+func Example() {
+	doc, err := openapi3.NewLoader().LoadFromFile("./testdata/petstore.yaml")
+	if err != nil {
+		panic(err)
+	}
+
+	router, err := gorillamux.NewRouter(doc)
+	if err != nil {
+		panic(err)
+	}
+
+	ts := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		route, pathParams, err := router.FindRoute(r)
+		if err != nil {
+			fmt.Println(err.Error())
+			w.WriteHeader(http.StatusInternalServerError)
+			return
+		}
+
+		err = openapi3filter.ValidateRequest(r.Context(), &openapi3filter.RequestValidationInput{
+			Request:    r,
+			PathParams: pathParams,
+			Route:      route,
+			Options: &openapi3filter.Options{
+				MultiError: true,
+			},
+		})
+		switch err := err.(type) {
+		case nil:
+		case openapi3.MultiError:
+			issues := convertError(err)
+			names := make([]string, 0, len(issues))
+			for k := range issues {
+				names = append(names, k)
+			}
+			sort.Strings(names)
+			for _, k := range names {
+				msgs := issues[k]
+				fmt.Println("===== Start New Error =====")
+				fmt.Println(k + ":")
+				for _, msg := range msgs {
+					fmt.Printf("\t%s\n", msg)
+				}
+			}
+			w.WriteHeader(http.StatusBadRequest)
+		default:
+			fmt.Println(err.Error())
+			w.WriteHeader(http.StatusBadRequest)
+		}
+	}))
+	defer ts.Close()
+
+	// (note invalid type for name and invalid status)
+	body := strings.NewReader(`{"name": 100, "photoUrls": [], "status": "invalidStatus"}`)
+	req, err := http.NewRequest("POST", ts.URL+"/pet", body)
+	if err != nil {
+		panic(err)
+	}
+	req.Header.Set("Content-Type", "application/json")
+	resp, err := http.DefaultClient.Do(req)
+	if err != nil {
+		panic(err)
+	}
+	defer resp.Body.Close()
+	fmt.Printf("response: %d %s\n", resp.StatusCode, resp.Body)
+
+	// Output:
+	// ===== Start New Error =====
+	// @body.name:
+	// 	Error at "/name": Field must be set to string or not be present
+	// Schema:
+	//   {
+	//     "example": "doggie",
+	//     "type": "string"
+	//   }
+	//
+	// Value:
+	//   "number, integer"
+	//
+	// ===== Start New Error =====
+	// @body.status:
+	// 	Error at "/status": value is not one of the allowed values
+	// Schema:
+	//   {
+	//     "description": "pet status in the store",
+	//     "enum": [
+	//       "available",
+	//       "pending",
+	//       "sold"
+	//     ],
+	//     "type": "string"
+	//   }
+	//
+	// Value:
+	//   "invalidStatus"
+	//
+	// response: 400 {}
+}
+
+const (
+	prefixBody = "@body"
+	unknown    = "@unknown"
+)
+
+func convertError(me openapi3.MultiError) map[string][]string {
+	issues := make(map[string][]string)
+	for _, err := range me {
+		switch err := err.(type) {
+		case *openapi3.SchemaError:
+			// Can inspect schema validation errors here, e.g. err.Value
+			field := prefixBody
+			if path := err.JSONPointer(); len(path) > 0 {
+				field = fmt.Sprintf("%s.%s", field, strings.Join(path, "."))
+			}
+			if _, ok := issues[field]; !ok {
+				issues[field] = make([]string, 0, 3)
+			}
+			issues[field] = append(issues[field], err.Error())
+		case *openapi3filter.RequestError: // possible there were multiple issues that failed validation
+			if err, ok := err.Err.(openapi3.MultiError); ok {
+				for k, v := range convertError(err) {
+					if _, ok := issues[k]; !ok {
+						issues[k] = make([]string, 0, 3)
+					}
+					issues[k] = append(issues[k], v...)
+				}
+				continue
+			}
+
+			// check if invalid HTTP parameter
+			if err.Parameter != nil {
+				prefix := err.Parameter.In
+				name := fmt.Sprintf("%s.%s", prefix, err.Parameter.Name)
+				if _, ok := issues[name]; !ok {
+					issues[name] = make([]string, 0, 3)
+				}
+				issues[name] = append(issues[name], err.Error())
+				continue
+			}
+
+			// check if requestBody
+			if err.RequestBody != nil {
+				if _, ok := issues[prefixBody]; !ok {
+					issues[prefixBody] = make([]string, 0, 3)
+				}
+				issues[prefixBody] = append(issues[prefixBody], err.Error())
+				continue
+			}
+		default:
+			reasons, ok := issues[unknown]
+			if !ok {
+				reasons = make([]string, 0, 3)
+			}
+			reasons = append(reasons, err.Error())
+			issues[unknown] = reasons
+		}
+	}
+	return issues
+}

openapi3filter/validate_request_test.go → routers/legacy/validate_request_test.go

@@ -1,4 +1,4 @@
-package openapi3filter_test
+package legacy_test
 
 import (
 	"bytes"
@@ -8,7 +8,7 @@ import (
 
 	"github.com/getkin/kin-openapi/openapi3"
 	"github.com/getkin/kin-openapi/openapi3filter"
-	legacyrouter "github.com/getkin/kin-openapi/routers/legacy"
+	"github.com/getkin/kin-openapi/routers/legacy"
 )
 
 const spec = `
@@ -73,7 +73,7 @@ func Example() {
 		panic(err)
 	}
 
-	router, err := legacyrouter.NewRouter(doc)
+	router, err := legacy.NewRouter(doc)
 	if err != nil {
 		panic(err)
 	}