Check command and error details (#29)

* add check command to verify validity of a script
* add details field to /script api responses in case of an error, with a url to numscript playground showing the formatted error

api/http.go

@@ -3,6 +3,10 @@ package api
 import (
 	"context"
 	_ "embed"
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+	"log"
 	"strings"
 
 	"github.com/gin-contrib/cors"
@@ -118,7 +122,18 @@ func NewHttpAPI(lc fx.Lifecycle, resolver *ledger.Resolver) *HttpAPI {
 		}
 
 		if err != nil {
-			res["err"] = err.Error()
+			err_str := err.Error()
+			err_str = strings.ReplaceAll(err_str, "\n", "\r\n")
+			payload, err := json.Marshal(gin.H{
+				"error": err_str,
+			})
+			if err != nil {
+				log.Fatal(err)
+			}
+			payload_b64 := base64.StdEncoding.EncodeToString([]byte(payload))
+			link := fmt.Sprintf("https://play.numscript.org/?payload=%v", payload_b64)
+			res["err"] = err_str
+			res["details"] = link
 		}
 
 		c.JSON(200, res)

cmd/root.go

@@ -15,6 +15,7 @@ import (
 	"github.com/numary/ledger/config"
 	"github.com/numary/ledger/ledger"
 	"github.com/numary/ledger/storage"
+	"github.com/numary/machine/script/compiler"
 	"github.com/spf13/cobra"
 	"github.com/spf13/viper"
 	"go.uber.org/fx"
@@ -91,7 +92,7 @@ func Execute() {
 		},
 	})
 
-	script := &cobra.Command{
+	script_exec := &cobra.Command{
 		Use:  "exec [ledger] [script]",
 		Args: cobra.ExactArgs(2),
 		Run: func(cmd *cobra.Command, args []string) {
@@ -144,18 +145,40 @@ func Execute() {
 				log.Fatal(err)
 			}
 			if result.Ok {
-				fmt.Println("Script ran successfully 👍")
+				fmt.Println("Script ran successfully ✅")
 			} else {
 				log.Fatal(result.Err)
 			}
 		},
 	}
 
+	script_check := &cobra.Command{
+		Use:  "check [script]",
+		Args: cobra.ExactArgs(1),
+		Run: func(cmd *cobra.Command, args []string) {
+			config.Init()
+
+			b, err := ioutil.ReadFile(args[0])
+
+			if err != nil {
+				log.Fatal(err)
+			}
+
+			_, err = compiler.Compile(string(b))
+			if err != nil {
+				log.Fatal(err)
+			} else {
+				fmt.Println("Script is correct ✅")
+			}
+		},
+	}
+
 	root.AddCommand(server)
 	root.AddCommand(conf)
 	root.AddCommand(UICmd)
 	root.AddCommand(store)
-	root.AddCommand(script)
+	root.AddCommand(script_exec)
+	root.AddCommand(script_check)
 
 	if err := root.Execute(); err != nil {
 		fmt.Fprintln(os.Stderr, err)