From 3ed07f543d993a75c2ddb3e3d1e47cd1a825dce95509cd1cfa61b73c6668ff0b Mon Sep 17 00:00:00 2001
From: Sergey Matveev <stargrave@stargrave.org>
Date: Fri, 4 Apr 2025 13:05:55 +0300
Subject: [PATCH] Less panics, more checks

---
 go/schema/check.go | 47 ++++++++++++++++++++++++++++++++++++----------
 1 file changed, 37 insertions(+), 10 deletions(-)

diff --git a/go/schema/check.go b/go/schema/check.go
index 9143eab..6b48831 100644
--- a/go/schema/check.go
+++ b/go/schema/check.go
@@ -47,7 +47,14 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 	var single bool // TAKEn, not EACH
 	var vs []any
 	for i, act := range acts {
-		switch cmd := act[0].(string); cmd {
+		if len(act) == 0 {
+			return fmt.Errorf("%s: %d: empty command", schemaName, i)
+		}
+		cmd, ok := act[0].(string)
+		if !ok {
+			return fmt.Errorf("%s: %d: non command: %+v", schemaName, i, act[0])
+		}
+		switch cmd {
 		case CmdExists:
 			if vs == nil {
 				return fmt.Errorf("%s: %d: %s", schemaName, i, cmd)
@@ -58,6 +65,9 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 			}
 		case CmdTake:
 			single = true
+			if len(act) != 2 {
+				return fmt.Errorf("%s: %d: %s: wrong number of args", schemaName, i, cmd)
+			}
 			switch k := act[1].(type) {
 			case string:
 				if k == "." {
@@ -75,7 +85,7 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 				l := data.([]any)
 				vs = []any{l[k]}
 			default:
-				panic("bad take target")
+				return fmt.Errorf("%s: %d: %s: bad target", schemaName, i, cmd)
 			}
 		case CmdEach:
 			single = false
@@ -99,8 +109,15 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 				continue
 			}
 			expected := make([]types.Type, 0, len(act)-1)
-			for _, t := range act[1:] {
-				switch t := t.(string); t {
+			if len(act) < 2 {
+				return fmt.Errorf("%s: %d: %s: wrong number of args", schemaName, i, cmd)
+			}
+			for _, tAny := range act[1:] {
+				t, ok := tAny.(string)
+				if !ok {
+					return fmt.Errorf("%s: %d: %s: non-str: %+v", schemaName, i, cmd, tAny)
+				}
+				switch t {
 				case "NIL":
 					expected = append(expected, types.NIL)
 				case "BOOL":
@@ -124,7 +141,7 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 				case "STR":
 					expected = append(expected, types.Str)
 				default:
-					panic("unknown type: " + t)
+					return fmt.Errorf("%s: %d: %s: unknown type: %s", schemaName, i, cmd, t)
 				}
 			}
 			var typ types.Type
@@ -161,7 +178,7 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 				case keks.Raw:
 					typ = types.Raw
 				default:
-					panic(fmt.Errorf("unsupported type: %+v", v))
+					return fmt.Errorf("%s: %d: %s: unsupported type: %T", schemaName, i, cmd, v)
 				}
 				if !slices.Contains(expected, typ) {
 					return fmt.Errorf("%s: %d: %d: %s: %T", schemaName, i, n, cmd, v)
@@ -172,13 +189,16 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 				continue
 			}
 			var expect int64
+			if len(act) != 2 {
+				return fmt.Errorf("%s: %d: %s: wrong number of args", schemaName, i, cmd)
+			}
 			switch v := act[1].(type) {
 			case uint64:
 				expect = int64(v)
 			case int64:
 				expect = v
 			default:
-				panic(fmt.Errorf("unsupported type: %+v", v))
+				return fmt.Errorf("%s: %d: %s: unsupported type: %T", schemaName, i, cmd, v)
 			}
 			for _, v := range vs {
 				var got int64
@@ -197,7 +217,7 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 					case int64:
 						got = v
 					default:
-						panic("non len-able")
+						return fmt.Errorf("%s: %d: %s: non len-able: %T", schemaName, i, cmd, v)
 					}
 				}
 				switch cmd {
@@ -215,13 +235,20 @@ func Check(schemaName string, schemas map[string][][]any, data any) error {
 			if vs == nil {
 				continue
 			}
+			if len(act) != 2 {
+				return fmt.Errorf("%s: %d: %s: wrong number of args", schemaName, i, cmd)
+			}
+			name, ok := act[1].(string)
+			if !ok {
+				return fmt.Errorf("%s: %d: %s: bad name: %+v", schemaName, i, cmd, act[1])
+			}
 			for n, v := range vs {
-				if err := Check(act[1].(string), schemas, v); err != nil {
+				if err := Check(name, schemas, v); err != nil {
 					return fmt.Errorf("%s: %d: %d: %s: %w", schemaName, i, n, cmd, err)
 				}
 			}
 		default:
-			panic("unknown command: " + cmd)
+			return fmt.Errorf("%s: %d: %s: unknown command", schemaName, i, cmd)
 		}
 	}
 	return nil
-- 
2.48.1