From 2dc6ab3896e876d7ec2371b3faa6112971e9e849 Mon Sep 17 00:00:00 2001
From: Anton Kaliaev <anton.kalyaev@gmail.com>
Date: Wed, 8 Mar 2017 17:16:01 +0400
Subject: [PATCH] use golang default if an arg is missing (Refs #7)

---
 server/handlers.go       | 54 +++++++++++++++++++++++-----------------
 test/integration_test.sh | 19 +++++++++++++-
 2 files changed, 49 insertions(+), 24 deletions(-)

diff --git a/server/handlers.go b/server/handlers.go
index beb664d9f..7085b81e2 100644
--- a/server/handlers.go
+++ b/server/handlers.go
@@ -141,20 +141,20 @@ func makeJSONRPCHandler(funcMap map[string]*RPCFunc) http.HandlerFunc {
 
 // Convert a list of interfaces to properly typed values
 func jsonParamsToArgs(rpcFunc *RPCFunc, params map[string]interface{}) ([]reflect.Value, error) {
-	if len(rpcFunc.argNames) != len(params) {
-		return nil, fmt.Errorf("Expected %v parameters (%v), got %v (%v)",
-			len(rpcFunc.argNames), rpcFunc.argNames, len(params), params)
-	}
+	values := make([]reflect.Value, len(rpcFunc.args))
 
-	values := make([]reflect.Value, len(params))
+	// fill each value with default
+	for i, argType := range rpcFunc.args {
+		values[i] = reflect.Zero(argType)
+	}
 
 	for name, param := range params {
 		i := indexOf(name, rpcFunc.argNames)
 		if -1 == i {
 			return nil, fmt.Errorf("%s is not an argument (args: %v)", name, rpcFunc.argNames)
 		}
-		ty := rpcFunc.args[i]
-		v, err := _jsonObjectToArg(ty, param)
+		argType := rpcFunc.args[i]
+		v, err := _jsonObjectToArg(argType, param)
 		if err != nil {
 			return nil, err
 		}
@@ -176,21 +176,21 @@ func indexOf(value string, values []string) int {
 
 // Same as above, but with the first param the websocket connection
 func jsonParamsToArgsWS(rpcFunc *RPCFunc, params map[string]interface{}, wsCtx types.WSRPCContext) ([]reflect.Value, error) {
-	if len(rpcFunc.argNames) != len(params) {
-		return nil, fmt.Errorf("Expected %v parameters (%v), got %v (%v)",
-			len(rpcFunc.argNames)-1, rpcFunc.argNames[1:], len(params), params)
-	}
-
-	values := make([]reflect.Value, len(params)+1)
+	values := make([]reflect.Value, len(rpcFunc.args))
 	values[0] = reflect.ValueOf(wsCtx)
 
+	// fill each value with default
+	for i, argType := range rpcFunc.args {
+		values[i+1] = reflect.Zero(argType)
+	}
+
 	for name, param := range params {
 		i := indexOf(name, rpcFunc.argNames)
 		if -1 == i {
 			return nil, fmt.Errorf("%s is not an argument (args: %v)", name, rpcFunc.argNames)
 		}
-		ty := rpcFunc.args[i+1]
-		v, err := _jsonObjectToArg(ty, param)
+		argType := rpcFunc.args[i+1]
+		v, err := _jsonObjectToArg(argType, param)
 		if err != nil {
 			return nil, err
 		}
@@ -245,16 +245,23 @@ func makeHTTPHandler(rpcFunc *RPCFunc) func(http.ResponseWriter, *http.Request)
 // Covert an http query to a list of properly typed values.
 // To be properly decoded the arg must be a concrete type from tendermint (if its an interface).
 func httpParamsToArgs(rpcFunc *RPCFunc, r *http.Request) ([]reflect.Value, error) {
-	argTypes := rpcFunc.args
-	argNames := rpcFunc.argNames
+	values := make([]reflect.Value, len(rpcFunc.args))
 
-	values := make([]reflect.Value, len(argNames))
-	for i, name := range argNames {
-		ty := argTypes[i]
+	// fill each value with default
+	for i, argType := range rpcFunc.args {
+		values[i] = reflect.Zero(argType)
+	}
+
+	for i, name := range rpcFunc.argNames {
+		argType := rpcFunc.args[i]
 		arg := GetParam(r, name)
-		// log.Notice("param to arg", "ty", ty, "name", name, "arg", arg)
+		// log.Notice("param to arg", "argType", argType, "name", name, "arg", arg)
+
+		if "" == arg {
+			continue
+		}
 
-		v, err, ok := nonJsonToArg(ty, arg)
+		v, err, ok := nonJsonToArg(argType, arg)
 		if err != nil {
 			return nil, err
 		}
@@ -264,11 +271,12 @@ func httpParamsToArgs(rpcFunc *RPCFunc, r *http.Request) ([]reflect.Value, error
 		}
 
 		// Pass values to go-wire
-		values[i], err = _jsonStringToArg(ty, arg)
+		values[i], err = _jsonStringToArg(argType, arg)
 		if err != nil {
 			return nil, err
 		}
 	}
+
 	return values, nil
 }
 
diff --git a/test/integration_test.sh b/test/integration_test.sh
index 5c85704be..ea246c896 100755
--- a/test/integration_test.sh
+++ b/test/integration_test.sh
@@ -28,6 +28,7 @@ if [[ "$R1" != "$R2" ]]; then
 	echo "responses are not identical:"
 	echo "R1: $R1"
 	echo "R2: $R2"
+	echo "FAIL"
 	exit 1
 else
 	echo "OK"
@@ -40,18 +41,33 @@ if [[ "$R1" != "$R2" ]]; then
 	echo "responses are not identical:"
 	echo "R1: $R1"
 	echo "R2: $R2"
+	echo "FAIL"
 	exit 1
 else
 	echo "OK"
 fi
 
-# request with unquoted string arg
+echo "==> request with missing params"
+R1=$(curl -s 'http://localhost:8008/hello_world')
+R2='{"jsonrpc":"2.0","id":"","result":{"Result":"hi  0"},"error":""}'
+if [[ "$R1" != "$R2" ]]; then
+  echo "responses are not identical:"
+  echo "R1: $R1"
+  echo "R2: $R2"
+	echo "FAIL"
+  exit 1
+else
+  echo "OK"
+fi
+
+echo "==> request with unquoted string arg"
 R1=$(curl -s 'http://localhost:8008/hello_world?name=abcd&num=123')
 R2="{\"jsonrpc\":\"2.0\",\"id\":\"\",\"result\":null,\"error\":\"Error converting http params to args: invalid character 'a' looking for beginning of value\"}"
 if [[ "$R1" != "$R2" ]]; then
 	echo "responses are not identical:"
 	echo "R1: $R1"
 	echo "R2: $R2"
+	echo "FAIL"
 	exit 1
 else
 	echo "OK"
@@ -64,6 +80,7 @@ if [[ "$R1" != "$R2" ]]; then
 	echo "responses are not identical:"
 	echo "R1: $R1"
 	echo "R2: $R2"
+	echo "FAIL"
 	exit 1
 else
 	echo "OK"