fix: mapped number types in Record syntax (#2418)

Author: srsudar

src/NodeParser/MappedTypeNodeParser.ts

@@ -52,18 +52,20 @@ export class MappedTypeNodeParser implements SubNodeParser {
             return new ObjectType(id, [], this.getProperties(node, new UnionType([keyListType]), context), false);
         }
 
+        const maybeUnionType = this.childNodeParser.createType(
+            node.type!,
+            this.createSubContext(node, keyListType, context),
+        );
+        if (maybeUnionType instanceof UnionType && constraintType?.getId() === "number") {
+            // Then we turn it into an array
+            return maybeUnionType instanceof NeverType ? new NeverType() : new ArrayType(maybeUnionType);
+        }
+
         if (
             keyListType instanceof StringType ||
             keyListType instanceof NumberType ||
             keyListType instanceof SymbolType
         ) {
-            if (constraintType?.getId() === "number") {
-                const type = this.childNodeParser.createType(
-                    node.type!,
-                    this.createSubContext(node, keyListType, context),
-                );
-                return type instanceof NeverType ? new NeverType() : new ArrayType(type);
-            }
             // Key type widens to `string`
             const type = this.childNodeParser.createType(node.type!, this.createSubContext(node, keyListType, context));
             // const resultType = type instanceof NeverType ? new NeverType() : new ObjectType(id, [], [], type);

test/valid-data/type-mapped-number/index.test.ts

@@ -1,4 +1,4 @@
 import { assertValidSchema } from "../../utils";
 import { test } from "node:test";
 
-test("type-mapped-number", assertValidSchema("type-mapped-number", "MyObject"));
+test("type-mapped-number", assertValidSchema("type-mapped-number", "*"));

test/valid-data/type-mapped-number/main.ts

@@ -1 +1,5 @@
 export type MyObject = Record<number, string>;
+
+export type MyObjectKVSyntax = {
+    [key: number]: string;
+};

test/valid-data/type-mapped-number/schema.json

@@ -1,12 +1,17 @@
 {
-  "$ref": "#/definitions/MyObject",
   "$schema": "http://json-schema.org/draft-07/schema#",
   "definitions": {
     "MyObject": {
-      "items": {
+      "additionalProperties": {
         "type": "string"
       },
-      "type": "array"
+      "type": "object"
+    },
+    "MyObjectKVSyntax": {
+      "additionalProperties": {
+        "type": "string"
+      },
+      "type": "object"
     }
   }
 }