fix: add support for external refs

Author: Mark Fejes

package-lock.json

@@ -38,6 +38,7 @@
     "ajv-formats": "^2.0.0"
   },
   "dependencies": {
+    "@apidevtools/json-schema-ref-parser": "^9.0.9",
     "@openapi-contrib/openapi-schema-to-json-schema": "^3.0.4",
     "ajv": "^8.0.0",
     "ajv-formats": "^2.0.0",

package.json

@@ -1,6 +1,8 @@
 import jsYaml from 'js-yaml'
 import { JSONSchema } from 'json-schema-to-typescript';
+import $RefParser from  '@apidevtools/json-schema-ref-parser';
 import { readFileSync } from 'fs';
+import { dirname } from 'path';
 
 const toJsonSchema = require('@openapi-contrib/openapi-schema-to-json-schema');
 
@@ -12,7 +14,7 @@ export interface ParsedSchema {
   whitelistedDecoders: string[] | undefined;
 }
 
-export function parseSchema(inputFilePath: string, schemaType: SchemaType): ParsedSchema {
+export async function parseSchema(inputFilePath: string, schemaType: SchemaType): Promise<ParsedSchema> {
   switch (schemaType) {
     case 'json':
     case 'yaml':
@@ -22,7 +24,7 @@ export function parseSchema(inputFilePath: string, schemaType: SchemaType): Pars
   }
 }
 
-function parseOpenApiSchema(inputFilePath: string, schemaType: 'yaml' | 'json'): ParsedSchema {
+async function parseOpenApiSchema(inputFilePath: string, schemaType: 'yaml' | 'json'): Promise<ParsedSchema> {
   let schema: any;
 
   const inputFileContent = readFileSync(inputFilePath, 'utf8');
@@ -33,6 +35,14 @@ function parseOpenApiSchema(inputFilePath: string, schemaType: 'yaml' | 'json'):
     schema = JSON.parse(inputFileContent);
   }
 
+  // need to change to input file base directory, so relative ref paths can be resolved
+  const originalDirectory = process.cwd();
+  process.chdir(dirname(inputFilePath));
+  // resolve external references to original schema
+  schema = await $RefParser.bundle(schema)
+  // change back to original directory
+  process.chdir(originalDirectory);
+
   const properties: Record<string, any> = {};
   const definitions: Record<string, JSONSchema> = {};
 

src/parse-schema.ts

@@ -0,0 +1,6 @@
+components:
+  schemas:
+    UserList:
+      type: array
+      items:
+        $ref: './user.yaml#/definitions/User'

tests/schemas/schema-with-external-ref.yaml

@@ -0,0 +1,9 @@
+definitions:
+  User:
+    type: object
+    properties:
+      id:
+        type: string
+      name:
+        type: string
+    required: ['id']

tests/schemas/user.yaml

@@ -0,0 +1,23 @@
+import path from "path";
+import fs from "fs";
+import { generate } from "openapi-typescript-validator";
+
+describe("schema-with-external-ref", () => {
+  const name = "schema-with-external-ref";
+  const generatedDir = path.join(__dirname, "../generated", name);
+  const schemaDir = path.join(__dirname, "../schemas");
+
+  beforeAll(async () => {
+    if (fs.existsSync(generatedDir))
+      fs.rmdirSync(generatedDir, { recursive: true });
+  });
+
+  test('schema with external ref', async () => {
+    await generate({
+      schemaFile: path.join(schemaDir, "schema-with-external-ref.yaml"),
+      schemaType: "yaml",
+      directory: generatedDir
+    });
+  });
+
+});