From 91abe796603a4f12f93fbd45fc24b7c98291fda1 Mon Sep 17 00:00:00 2001
From: "Daniel G. Taylor" <danielgtaylor@gmail.com>
Date: Tue, 12 Mar 2019 23:07:28 -0700
Subject: [PATCH] Add readOnly/writeOnly support. Part 1 of #30

---
 CHANGELOG.md    |  1 +
 apisprout.go    |  2 +-
 example.go      | 49 +++++++++++++++++++++++++++++++++++++++++--------
 example_test.go | 46 +++++++++++++++++++++++++++++++++++++++++++++-
 4 files changed, 88 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 75a5030..72637df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -5,6 +5,7 @@ The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
 ## [Unreleased]
+- Add `readOnly` and `writeOnly` support to the example generator.
 - Revamped support for `--validate-server` (short `-s`)
   - Requires the use of server base path(s) on the client.
   - Localhost is now always allowed on all known base paths.
diff --git a/apisprout.go b/apisprout.go
index d57fa10..ece1385 100644
--- a/apisprout.go
+++ b/apisprout.go
@@ -153,7 +153,7 @@ func getTypedExample(mt *openapi3.MediaType) (interface{}, error) {
 	}
 
 	if mt.Schema != nil {
-		return OpenAPIExample(mt.Schema.Value)
+		return OpenAPIExample(ModeResponse, mt.Schema.Value)
 	}
 	// TODO: generate data from JSON schema, if no examples available?
 
diff --git a/example.go b/example.go
index a44a477..b2d13ba 100644
--- a/example.go
+++ b/example.go
@@ -6,6 +6,16 @@ import (
 	"github.com/getkin/kin-openapi/openapi3"
 )
 
+// Mode defines a mode of operation for example generation.
+type Mode int
+
+const (
+	// ModeRequest is for the request body (writes to the server)
+	ModeRequest Mode = iota
+	// ModeResponse is for the response body (reads from the server)
+	ModeResponse
+)
+
 func getSchemaExample(schema *openapi3.Schema) (interface{}, bool) {
 	if schema.Example != nil {
 		return schema.Example, true
@@ -66,10 +76,26 @@ func stringFormatExample(format string) string {
 	return ""
 }
 
+// excludeFromMode will exclude a schema if the mode is request and the schema
+// is read-only, or if the mode is response and the schema is write only.
+func excludeFromMode(mode Mode, schema *openapi3.Schema) bool {
+	if schema == nil {
+		return true
+	}
+
+	if mode == ModeRequest && schema.ReadOnly {
+		return true
+	} else if mode == ModeResponse && schema.WriteOnly {
+		return true
+	}
+
+	return false
+}
+
 // OpenAPIExample creates an example structure from an OpenAPI 3 schema
 // object, which is an extended subset of JSON Schema.
 // https://github.com/OAI/OpenAPI-Specification/blob/master/versions/3.0.1.md#schemaObject
-func OpenAPIExample(schema *openapi3.Schema) (interface{}, error) {
+func OpenAPIExample(mode Mode, schema *openapi3.Schema) (interface{}, error) {
 	if ex, ok := getSchemaExample(schema); ok {
 		return ex, nil
 	}
@@ -133,7 +159,7 @@ func OpenAPIExample(schema *openapi3.Schema) (interface{}, error) {
 		example := []interface{}{}
 
 		if schema.Items != nil && schema.Items.Value != nil {
-			ex, err := OpenAPIExample(schema.Items.Value)
+			ex, err := OpenAPIExample(mode, schema.Items.Value)
 			if err != nil {
 				return nil, fmt.Errorf("can't get example for array item")
 			}
@@ -150,7 +176,11 @@ func OpenAPIExample(schema *openapi3.Schema) (interface{}, error) {
 		example := map[string]interface{}{}
 
 		for k, v := range schema.Properties {
-			ex, err := OpenAPIExample(v.Value)
+			if excludeFromMode(mode, v.Value) {
+				continue
+			}
+
+			ex, err := OpenAPIExample(mode, v.Value)
 			if err != nil {
 				return nil, fmt.Errorf("can't get example for '%s'", k)
 			}
@@ -160,12 +190,15 @@ func OpenAPIExample(schema *openapi3.Schema) (interface{}, error) {
 
 		if schema.AdditionalProperties != nil && schema.AdditionalProperties.Value != nil {
 			addl := schema.AdditionalProperties.Value
-			ex, err := OpenAPIExample(addl)
-			if err != nil {
-				return nil, fmt.Errorf("can't get example for additional properties")
-			}
 
-			example["additionalPropertyName"] = ex
+			if !excludeFromMode(mode, addl) {
+				ex, err := OpenAPIExample(mode, addl)
+				if err != nil {
+					return nil, fmt.Errorf("can't get example for additional properties")
+				}
+
+				example["additionalPropertyName"] = ex
+			}
 		}
 
 		return example, nil
diff --git a/example_test.go b/example_test.go
index 8a5ea92..941b687 100644
--- a/example_test.go
+++ b/example_test.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"encoding/json"
+	"strings"
 	"testing"
 
 	"github.com/getkin/kin-openapi/openapi3"
@@ -377,6 +378,45 @@ var schemaTests = []struct {
 		`{"type": "string", "default": "one", "example": "two"}`,
 		`"two"`,
 	},
+	// ----- Modes -----
+	{
+		"Request mode",
+		`{"type": "object", "required": ["normal", "readOnly", "writeOnly"],
+			"properties": {
+				"normal": {
+					"type": "string"
+				},
+				"readOnly": {
+					"type": "string",
+					"readOnly": true
+				},
+				"writeOnly": {
+					"type": "string",
+					"writeOnly": true
+				}
+			}
+		}`,
+		`{"normal": "string", "writeOnly": "string"}`,
+	},
+	{
+		"Response mode",
+		`{"type": "object", "required": ["normal", "readOnly", "writeOnly"],
+			"properties": {
+				"normal": {
+					"type": "string"
+				},
+				"readOnly": {
+					"type": "string",
+					"readOnly": true
+				},
+				"writeOnly": {
+					"type": "string",
+					"writeOnly": true
+				}
+			}
+		}`,
+		`{"normal": "string", "readOnly": "string"}`,
+	},
 }
 
 func TestGenExample(t *testing.T) {
@@ -385,7 +425,11 @@ func TestGenExample(t *testing.T) {
 			schema := &openapi3.Schema{}
 			err := schema.UnmarshalJSON([]byte(tt.in))
 			assert.NoError(t, err)
-			example, err := OpenAPIExample(schema)
+			m := ModeRequest
+			if strings.Contains(tt.name, "Response") {
+				m = ModeResponse
+			}
+			example, err := OpenAPIExample(m, schema)
 
 			if tt.out == "" {
 				// Expected to return an error.