Add JSONInputDecoder for array input support

Signed-off-by: Peter Broadhurst <peter.broadhurst@kaleido.io>

Author: peterbroadhurst

pkg/ffapi/apiserver_test.go

@@ -18,6 +18,7 @@ package ffapi
 
 import (
 	"context"
+	"encoding/json"
 	"fmt"
 	"io"
 	"net/http"
@@ -112,6 +113,29 @@ var utAPIRoute2 = &Route{
 	},
 }
 
+type testInputStruct struct {
+	Input1 string `json:"input1,omitempty"`
+}
+
+var utAPIRoute3 = &Route{
+	Name:        "utAPIRoute3",
+	Path:        "ut/utresource/{resourceid}/postbatch",
+	Method:      http.MethodPost,
+	Description: "post an array to check arrays go through ok",
+	JSONInputDecoder: func(req *http.Request, body io.Reader) (interface{}, error) {
+		var arrayInput []*testInputStruct
+		err := json.NewDecoder(body).Decode(&arrayInput)
+		return arrayInput, err
+	},
+	JSONInputValue:  func() interface{} { return []*testInputStruct{} },
+	JSONOutputValue: func() interface{} { return []*testInputStruct{} },
+	Extensions: &APIServerRouteExt[*utManager]{
+		JSONHandler: func(a *APIRequest, um *utManager) (output interface{}, err error) {
+			return a.Input.([]*testInputStruct), nil
+		},
+	},
+}
+
 func initUTConfig() (config.Section, config.Section, config.Section) {
 	config.RootConfigReset()
 	apiConfig := config.RootSection("ut.api")
@@ -129,7 +153,7 @@ func newTestAPIServer(t *testing.T, start bool) (*utManager, *apiServer[*utManag
 	um := &utManager{t: t}
 	as := NewAPIServer(ctx, APIServerOptions[*utManager]{
 		MetricsRegistry: metric.NewPrometheusMetricsRegistry("ut"),
-		Routes:          []*Route{utAPIRoute1, utAPIRoute2},
+		Routes:          []*Route{utAPIRoute1, utAPIRoute2, utAPIRoute3},
 		EnrichRequest: func(r *APIRequest) (*utManager, error) {
 			// This could be some dynamic object based on extra processing in the request,
 			// but the most common case is you just have a "manager" that you inject into each
@@ -176,6 +200,30 @@ func TestAPIServerInvokeAPIRouteStream(t *testing.T) {
 	assert.Equal(t, "a stream!", string(res.Body()))
 }
 
+func TestAPIServerInvokeAPIPostEmptyArray(t *testing.T) {
+	_, as, done := newTestAPIServer(t, true)
+	defer done()
+
+	<-as.Started()
+
+	var o []*testInputStruct
+	res, err := resty.New().R().
+		SetBody([]*testInputStruct{}).
+		SetResult(&o).
+		Post(fmt.Sprintf("%s/api/v1/ut/utresource/id12345/postbatch", as.APIPublicURL()))
+	assert.NoError(t, err)
+	assert.Equal(t, 200, res.StatusCode())
+	assert.Equal(t, []*testInputStruct{}, o)
+
+	res, err = resty.New().R().
+		SetBody([]*testInputStruct{{Input1: "in1"}}).
+		SetResult(&o).
+		Post(fmt.Sprintf("%s/api/v1/ut/utresource/id12345/postbatch", as.APIPublicURL()))
+	assert.NoError(t, err)
+	assert.Equal(t, 200, res.StatusCode())
+	assert.Equal(t, []*testInputStruct{{Input1: "in1"}}, o)
+}
+
 func TestAPIServerInvokeAPIRouteLiveness(t *testing.T) {
 	_, as, done := newTestAPIServer(t, true)
 	defer done()

pkg/ffapi/handler.go

@@ -216,7 +216,9 @@ func (hs *HandlerFactory) RouteHandler(route *Route) http.HandlerFunc {
 				req.Header.Set("Content-Type", "application/json; charset=utf8")
 				fallthrough
 			case strings.HasPrefix(strings.ToLower(contentType), "application/json"):
-				if jsonInput != nil {
+				if route.JSONInputDecoder != nil {
+					jsonInput, err = route.JSONInputDecoder(req, req.Body)
+				} else if jsonInput != nil {
 					d := json.NewDecoder(req.Body)
 					d.UseNumber()
 					err = d.Decode(&jsonInput)

pkg/ffapi/routes.go

@@ -19,6 +19,7 @@ package ffapi
 import (
 	"context"
 	"io"
+	"net/http"
 
 	"github.com/getkin/kin-openapi/openapi3"
 	"github.com/hyperledger/firefly-common/pkg/config"
@@ -52,6 +53,8 @@ type Route struct {
 	PreTranslatedDescription string
 	// FilterFactory models the filter fields that can be specified on the API, and will automatically be parsed
 	FilterFactory QueryFactory
+	// JSONInputDecoder is a function that does the decoding completely - needed (as this was written pre-generics) for handling arrays
+	JSONInputDecoder func(req *http.Request, body io.Reader) (interface{}, error)
 	// JSONInputValue is a function that returns a pointer to a structure to take JSON input
 	JSONInputValue func() interface{}
 	// JSONInputMask are fields that aren't available for users to supply on input