fix(ISSUE-810): oneOf/allOf/anyOf fixing (#830)

* fix(ISSUE-810): oneOf/allOf/anyOf with empty definitions at yaml generating error solving, also add tests

* fix(ISSUE-810): tests additional and immutable

Author: sadfsdfdsa

src/utils.ts

@@ -218,6 +218,8 @@ export function tsTupleOf(types: string[]): string {
 export function tsIntersectionOf(types: string[]): string {
   const typesWithValues = types.filter(Boolean);
 
+  if (!typesWithValues.length) return "undefined"; // usually allOf/anyOf with empty input - so it's undefined
+
   if (typesWithValues.length === 1) return typesWithValues[0]; // don’t add parentheses around one thing
   return `(${typesWithValues.join(") & (")})`;
 }
@@ -233,6 +235,8 @@ export function tsReadonly(immutable: boolean): string {
 
 /** Convert [X, Y, Z] into X | Y | Z */
 export function tsUnionOf(types: Array<string | number | boolean>): string {
+  if (!types.length) return "undefined"; // usually oneOf with empty input - so it's undefined
+
   if (types.length === 1) return `${types[0]}`; // don’t add parentheses around one thing
   return `(${types.join(") | (")})`;
 }

test/v3/specs/one-of-empty.yaml

@@ -0,0 +1,22 @@
+openapi: 3.0
+paths:
+  /test:
+    get:
+      tags:
+        - test
+      summary: "Just a test path"
+      responses:
+        200:
+          description: A list of types.
+components:
+  schemas:
+    Example:
+      description: Enum with null and nullable
+      type: object
+      properties:
+        emptyAllOf:
+          allOf: []
+        emptyOneOf:
+          oneOf: []
+        emptyAnyOf:
+          anyOf: []