openapi3: tests for #931 (#887)

* repro #883

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

* try harder

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

* skip yaml unmarshaler for maplike types for now

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

* docs.sh

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

---------

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

.github/docs/openapi3.txt

@@ -1696,7 +1696,7 @@ func (doc *T) JSONLookup(token string) (interface{}, error)
     JSONLookup implements
     https://pkg.go.dev/github.com/go-openapi/jsonpointer#JSONPointable
 
-func (doc T) MarshalJSON() ([]byte, error)
+func (doc *T) MarshalJSON() ([]byte, error)
     MarshalJSON returns the JSON encoding of T.
 
 func (doc *T) UnmarshalJSON(data []byte) error

openapi3/issue883_test.go

@@ -0,0 +1,103 @@
+package openapi3_test
+
+import (
+	"testing"
+
+	invopopYaml "github.com/invopop/yaml"
+	"github.com/stretchr/testify/require"
+	v3 "gopkg.in/yaml.v3"
+
+	"github.com/getkin/kin-openapi/openapi3"
+)
+
+func TestIssue883(t *testing.T) {
+	spec := `
+openapi: '3.0.0'
+info:
+  version: '1.0.0'
+  title: Swagger Petstore
+  license:
+    name: MIT
+servers:
+- url: http://petstore.swagger.io/v1
+paths:
+  /simple:
+    get:
+      summary: A simple GET request
+      responses:
+        '200':
+          description: OK
+`[1:]
+
+	sl := openapi3.NewLoader()
+	doc, err := sl.LoadFromData([]byte(spec))
+	require.NoError(t, err)
+	require.NotNil(t, doc.Paths)
+
+	err = doc.Validate(sl.Context)
+	require.NoError(t, err)
+	require.NotNil(t, doc.Paths)
+
+	t.Run("Roundtrip invopop/yaml", func(t *testing.T) {
+		justPaths, err := invopopYaml.Marshal(doc.Paths)
+		require.NoError(t, err)
+		require.NotNil(t, doc.Paths)
+		require.YAMLEq(t, `
+/simple:
+  get:
+    summary: A simple GET request
+    responses:
+      '200':
+        description: OK
+`[1:], string(justPaths))
+
+		marshalledYaml, err := invopopYaml.Marshal(doc)
+		require.NoError(t, err)
+		require.NotNil(t, doc.Paths)
+		require.YAMLEq(t, spec, string(marshalledYaml))
+
+		var newDoc openapi3.T
+		err = invopopYaml.Unmarshal(marshalledYaml, &newDoc)
+		require.NoError(t, err)
+		require.NotNil(t, newDoc.Paths)
+		require.Equal(t, doc, &newDoc)
+	})
+
+	t.Run("Roundtrip yaml.v3", func(t *testing.T) {
+		justPaths, err := doc.Paths.MarshalJSON()
+		require.NoError(t, err)
+		require.NotNil(t, doc.Paths)
+		require.YAMLEq(t, `
+/simple:
+  get:
+    summary: A simple GET request
+    responses:
+      '200':
+        description: OK
+`[1:], string(justPaths))
+
+		justPaths, err = v3.Marshal(doc.Paths)
+		require.NoError(t, err)
+		require.NotNil(t, doc.Paths)
+		require.YAMLEq(t, `
+/simple:
+  get:
+    summary: A simple GET request
+    responses:
+      '200':
+        description: OK
+`[1:], string(justPaths))
+
+		marshalledYaml, err := v3.Marshal(doc)
+		require.NoError(t, err)
+		require.NotNil(t, doc.Paths)
+		require.YAMLEq(t, spec, string(marshalledYaml))
+
+		t.Skip("TODO: impl https://pkg.go.dev/gopkg.in/yaml.v3#Unmarshaler on maplike types")
+		var newDoc openapi3.T
+		err = v3.Unmarshal(marshalledYaml, &newDoc)
+		require.NoError(t, err)
+		require.NotNil(t, newDoc.Paths)
+		require.Equal(t, doc, &newDoc)
+	})
+}

openapi3/openapi3.go

@@ -54,7 +54,7 @@ func (doc *T) JSONLookup(token string) (interface{}, error) {
 }
 
 // MarshalJSON returns the JSON encoding of T.
-func (doc T) MarshalJSON() ([]byte, error) {
+func (doc *T) MarshalJSON() ([]byte, error) {
 	m := make(map[string]interface{}, 4+len(doc.Extensions))
 	for k, v := range doc.Extensions {
 		m[k] = v