feat!: Standardize baseURL

- Remove long-deprecated `baseUrl`
- Use proper `base` URL logic via `new URL(url, base)`

README.md

@@ -44,13 +44,14 @@ over other authentication methods, i.e., application default credentials.
 ```js
 {
   // The url to which the request should be sent.  Required.
-  url: string,
+  url: string | URL,
 
   // The HTTP method to use for the request.  Defaults to `GET`.
   method: 'GET',
 
-  // The base Url to use for the request. Prepended to the `url` property above.
-  baseURL: 'https://example.com';
+  // The base Url to use for the request.
+  // Resolved as `new URL(url, baseURL)`
+  baseURL: 'https://example.com/v1/' | URL;
 
   // The HTTP methods to be sent with the request.
   headers: { 'some': 'header' },

src/common.ts

@@ -148,10 +148,6 @@ export interface GaxiosOptions {
     defaultAdapter: (options: GaxiosOptions) => GaxiosPromise<T>
   ) => GaxiosPromise<T>;
   url?: string | URL;
-  /**
-   * @deprecated
-   */
-  baseUrl?: string;
   baseURL?: string | URL;
   method?:
     | 'GET'

src/gaxios.ts

@@ -236,10 +236,10 @@ export class Gaxios {
       throw new Error('URL is required.');
     }
 
-    // baseUrl has been deprecated, remove in 2.0
-    const baseUrl = opts.baseUrl || opts.baseURL;
-    if (baseUrl) {
-      opts.url = baseUrl.toString() + opts.url;
+    if (opts.baseURL) {
+      const base =
+        opts.baseURL instanceof URL ? opts.baseURL : new URL(opts.baseURL);
+      opts.url = new URL(opts.url.toString(), base);
     }
 
     opts.paramsSerializer = opts.paramsSerializer || this.paramsSerializer;

test/test.getch.ts

@@ -162,8 +162,8 @@ describe('🥁 configuration options', () => {
 
   it('should allow setting a base url in the options', async () => {
     const scope = nock(url).get('/v1/mango').reply(200, {});
-    const inst = new Gaxios({baseURL: `${url}/v1`});
-    const res = await inst.request({url: '/mango'});
+    const inst = new Gaxios({baseURL: `${url}/v1/`});
+    const res = await inst.request({url: 'mango'});
     scope.done();
     assert.deepStrictEqual(res.data, {});
   });

test/test.retry.ts

@@ -141,14 +141,12 @@ describe('🛸 retry & exponential backoff', () => {
     scope.done();
   });
 
-  it('should retain the baseUrl on retry', async () => {
+  it('should retain the baseURL on retry', async () => {
     const body = {pumpkin: '🥧'};
     const url = '/path';
-    const baseUrl = 'http://example.com';
-    const scope = nock(baseUrl).get(url).reply(500).get(url).reply(200, body);
-    const gaxios = new Gaxios({
-      baseUrl,
-    });
+    const baseURL = 'http://example.com';
+    const scope = nock(baseURL).get(url).reply(500).get(url).reply(200, body);
+    const gaxios = new Gaxios({baseURL});
     const res = await gaxios.request({
       url,
       retry: true,