From 0b04c7dccad565bdbd75524608798d03ceb21433 Mon Sep 17 00:00:00 2001
From: daanboer <39552979+daanboer@users.noreply.github.com>
Date: Thu, 26 May 2022 15:44:13 +0200
Subject: [PATCH] feat: support empty mapped types (#1261)

---
 src/NodeParser/MappedTypeNodeParser.ts                |  5 +++++
 test/valid-data-type.test.ts                          |  2 ++
 test/valid-data/type-mapped-empty-exclude/main.ts     |  1 +
 test/valid-data/type-mapped-empty-exclude/schema.json | 10 ++++++++++
 test/valid-data/type-mapped-never/main.ts             |  1 +
 test/valid-data/type-mapped-never/schema.json         | 10 ++++++++++
 6 files changed, 29 insertions(+)
 create mode 100644 test/valid-data/type-mapped-empty-exclude/main.ts
 create mode 100644 test/valid-data/type-mapped-empty-exclude/schema.json
 create mode 100644 test/valid-data/type-mapped-never/main.ts
 create mode 100644 test/valid-data/type-mapped-never/schema.json

diff --git a/src/NodeParser/MappedTypeNodeParser.ts b/src/NodeParser/MappedTypeNodeParser.ts
index bae958e05..312332344 100644
--- a/src/NodeParser/MappedTypeNodeParser.ts
+++ b/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
diff --git a/test/valid-data-type.test.ts b/test/valid-data-type.test.ts
index 1bc376d36..d650fd9b5 100644
--- a/test/valid-data-type.test.ts
+++ b/test/valid-data-type.test.ts
@@ -96,6 +96,8 @@ 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"));
diff --git a/test/valid-data/type-mapped-empty-exclude/main.ts b/test/valid-data/type-mapped-empty-exclude/main.ts
new file mode 100644
index 000000000..cd509dde4
--- /dev/null
+++ b/test/valid-data/type-mapped-empty-exclude/main.ts
@@ -0,0 +1 @@
+export type MyObject = { [K in Exclude<"key", "key">]: never };
diff --git a/test/valid-data/type-mapped-empty-exclude/schema.json b/test/valid-data/type-mapped-empty-exclude/schema.json
new file mode 100644
index 000000000..88f128ddf
--- /dev/null
+++ b/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"
+    }
+  }
+}
diff --git a/test/valid-data/type-mapped-never/main.ts b/test/valid-data/type-mapped-never/main.ts
new file mode 100644
index 000000000..9a7847492
--- /dev/null
+++ b/test/valid-data/type-mapped-never/main.ts
@@ -0,0 +1 @@
+export type MyObject = { [K in never]: never };
diff --git a/test/valid-data/type-mapped-never/schema.json b/test/valid-data/type-mapped-never/schema.json
new file mode 100644
index 000000000..88f128ddf
--- /dev/null
+++ b/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"
+    }
+  }
+}