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

src/utils.ts

@@ -180,6 +180,8 @@ 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(") & (")})`;
 }
@@ -195,6 +197,8 @@ 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/expected/one-of-empty.additional.ts

@@ -0,0 +1,30 @@
+/**
+ * This file was auto-generated by openapi-typescript.
+ * Do not make direct changes to the file.
+ */
+
+export interface paths {
+  "/test": {
+    get: {
+      responses: {
+        /** A list of types. */
+        200: unknown;
+      };
+    };
+  };
+}
+
+export interface components {
+  schemas: {
+    /** @description Enum with null and nullable */
+    Example: {
+      emptyAllOf?: { [key: string]: unknown };
+      emptyOneOf?: undefined & { [key: string]: unknown };
+      emptyAnyOf?: { [key: string]: unknown };
+    } & { [key: string]: unknown };
+  };
+}
+
+export interface operations {}
+
+export interface external {}

test/v3/expected/one-of-empty.immutable.ts

@@ -0,0 +1,30 @@
+/**
+ * This file was auto-generated by openapi-typescript.
+ * Do not make direct changes to the file.
+ */
+
+export interface paths {
+  readonly "/test": {
+    readonly get: {
+      readonly responses: {
+        /** A list of types. */
+        readonly 200: unknown;
+      };
+    };
+  };
+}
+
+export interface components {
+  readonly schemas: {
+    /** @description Enum with null and nullable */
+    readonly Example: {
+      readonly emptyAllOf?: undefined;
+      readonly emptyOneOf?: undefined;
+      readonly emptyAnyOf?: undefined;
+    };
+  };
+}
+
+export interface operations {}
+
+export interface external {}

test/v3/expected/one-of-empty.ts

@@ -0,0 +1,30 @@
+/**
+ * This file was auto-generated by openapi-typescript.
+ * Do not make direct changes to the file.
+ */
+
+export interface paths {
+  "/test": {
+    get: {
+      responses: {
+        /** A list of types. */
+        200: unknown;
+      };
+    };
+  };
+}
+
+export interface components {
+  schemas: {
+    /** @description Enum with null and nullable */
+    Example: {
+      emptyAllOf?: undefined;
+      emptyOneOf?: undefined;
+      emptyAnyOf?: undefined;
+    };
+  };
+}
+
+export interface operations {}
+
+export interface external {}

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: []