feat: support empty mapped types

src/NodeParser/MappedTypeNodeParser.ts

@@ -7,6 +7,7 @@ import { ArrayType } from "../Type/ArrayType";
 import { BaseType } from "../Type/BaseType";
 import { EnumType, EnumValue } from "../Type/EnumType";
 import { LiteralType } from "../Type/LiteralType";
+import { NeverType } from "../Type/NeverType";
 import { NumberType } from "../Type/NumberType";
 import { ObjectProperty, ObjectType } from "../Type/ObjectType";
 import { StringType } from "../Type/StringType";
@@ -58,6 +59,10 @@ export class MappedTypeNodeParser implements SubNodeParser {
             return type === undefined ? undefined : new ArrayType(type);
         } else if (keyListType instanceof EnumType) {
             return new ObjectType(id, [], this.getValues(node, keyListType, context), false);
+        } else if (keyListType instanceof NeverType) {
+            return new ObjectType(id, [], [], false);
+        } else if (keyListType === undefined) {
+            return new ObjectType(id, [], [], false);
         } else {
             throw new LogicError(
                 // eslint-disable-next-line max-len

test/valid-data-type.test.ts

@@ -95,6 +95,8 @@ describe("valid-data-type", () => {
     it("type-mapped-exclude", assertValidSchema("type-mapped-exclude", "MyObject", "extended"));
     it("type-mapped-double-exclude", assertValidSchema("type-mapped-double-exclude", "MyObject", "extended"));
     it("type-mapped-symbol", assertValidSchema("type-mapped-symbol", "MyObject"));
+    it("type-mapped-never", assertValidSchema("type-mapped-never", "MyObject"));
+    it("type-mapped-empty-exclude", assertValidSchema("type-mapped-empty-exclude", "MyObject"));
     it("type-mapped-annotated-string", assertValidSchema("type-mapped-annotated-string", "ExchangeRate", "extended"));
 
     it("type-conditional-simple", assertValidSchema("type-conditional-simple", "MyObject"));

test/valid-data/type-mapped-empty-exclude/main.ts

@@ -0,0 +1 @@
+export type MyObject = { [K in Exclude<"key", "key">]: never };

test/valid-data/type-mapped-empty-exclude/schema.json

@@ -0,0 +1,10 @@
+{
+  "$ref": "#/definitions/MyObject",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "MyObject": {
+      "additionalProperties": false,
+      "type": "object"
+    }
+  }
+}

test/valid-data/type-mapped-never/main.ts

@@ -0,0 +1 @@
+export type MyObject = { [K in never]: never };

test/valid-data/type-mapped-never/schema.json

@@ -0,0 +1,10 @@
+{
+  "$ref": "#/definitions/MyObject",
+  "$schema": "http://json-schema.org/draft-07/schema#",
+  "definitions": {
+    "MyObject": {
+      "additionalProperties": false,
+      "type": "object"
+    }
+  }
+}