handle case where additionalRef is a ref (fixes #345)

src/utils.ts

@@ -1,4 +1,4 @@
-import { OpenAPI2, OpenAPI3 } from "./types";
+import { OpenAPI2, OpenAPI2Reference, OpenAPI2SchemaObject, OpenAPI3 } from "./types";
 
 export function comment(text: string): string {
   return `/**
@@ -121,3 +121,9 @@ export function unrefComponent(components: any, ref: string): any {
   const [type, object] = ref.match(/(?<=\[")([^"]+)/g) as string[];
   return components[type][object];
 }
+
+export function isOpenAPI2Reference(
+  additionalProperties: OpenAPI2SchemaObject | OpenAPI2Reference | boolean
+): additionalProperties is OpenAPI2Reference {
+  return (additionalProperties as OpenAPI2Reference).$ref !== undefined;
+}

src/v2.ts

@@ -1,6 +1,6 @@
 import propertyMapper from "./property-mapper";
-import { OpenAPI2, OpenAPI2SchemaObject, OpenAPI2Schemas, SwaggerToTSOptions } from "./types";
-import { comment, nodeType, transformRef, tsArrayOf, tsIntersectionOf, tsUnionOf } from "./utils";
+import { OpenAPI2, OpenAPI2Reference, OpenAPI2SchemaObject, OpenAPI2Schemas, SwaggerToTSOptions } from "./types";
+import { comment, nodeType, transformRef, tsArrayOf, tsIntersectionOf, tsUnionOf, isOpenAPI2Reference } from "./utils";
 
 export const PRIMITIVES: { [key: string]: "boolean" | "string" | "number" } = {
   // boolean types
@@ -40,6 +40,14 @@ export default function generateTypesV2(input: OpenAPI2 | OpenAPI2Schemas, optio
   // propertyMapper
   const propertyMapped = options ? propertyMapper(definitions, options.propertyMapper) : definitions;
 
+  //this functionality could perhaps be added to the nodeType function, but I don't want to mess with that code
+  function getAdditionalPropertiesType(additionalProperties: OpenAPI2SchemaObject | OpenAPI2Reference | boolean) {
+    if (isOpenAPI2Reference(additionalProperties)) {
+      return transformRef(additionalProperties.$ref, rawSchema ? "definitions/" : "");
+    }
+    return nodeType(additionalProperties);
+  }
+
   // type conversions
   function transform(node: OpenAPI2SchemaObject): string {
     switch (nodeType(node)) {
@@ -67,7 +75,7 @@ export default function generateTypesV2(input: OpenAPI2 | OpenAPI2Schemas, optio
 
         // if additional properties, add to end of properties
         if (node.additionalProperties) {
-          properties += `[key: string]: ${nodeType(node.additionalProperties) || "any"};\n`;
+          properties += `[key: string]: ${getAdditionalPropertiesType(node.additionalProperties) || "any"};\n`;
         }
 
         return tsIntersectionOf([

tests/v2/index.test.ts

@@ -255,6 +255,38 @@ describe("transformation", () => {
       );
     });
 
+    it("additionalProperties 2 (issue #345)", () => {
+      const schema: OpenAPI2 = {
+        swagger: "2.0",
+        definitions: {
+          Messages: {
+            type: "object",
+            additionalProperties: {
+              $ref: "#/definitions/Message",
+            },
+          },
+          Message: {
+            type: "object",
+            properties: {
+              code: {
+                type: "integer",
+              },
+              text: {
+                type: "string",
+              },
+            },
+          },
+        },
+      };
+      expect(swaggerToTS(schema)).toBe(
+        format(`
+        export interface definitions {
+          Messages: { [key: string]: definitions["Message"] }
+          Message: { code?: number; text?: string }
+        }`)
+      );
+    });
+
     it("allOf", () => {
       const schema: OpenAPI2 = {
         swagger: "2.0",