fix: unclear error message is thrown when specifying an empty proxy authorization (#6314)

* fix: add AxiosError to Invalid proxy authorization

* fix: minor update

* Update test/unit/adapters/http.js

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* chore: remove redundant check

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* chore: code style

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* chore: style

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

* chore: correct assert

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

---------

Co-authored-by: João Gabriel Quaresma de Almeida <joaoGabriel55>
Co-authored-by: Jay <jasonsaayman@gmail.com>
Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

lib/adapters/http.js

@@ -193,12 +193,16 @@ function setProxy(options, configProxy, location) {
 
     if (proxy.auth) {
       // Support proxy auth object form
-      if (proxy.auth.username || proxy.auth.password) {
+      const validProxyAuth = Boolean(proxy.auth.username || proxy.auth.password);
+
+      if (validProxyAuth) {
         proxy.auth = (proxy.auth.username || '') + ':' + (proxy.auth.password || '');
+      } else if (typeof proxy.auth === 'object') {
+        throw new AxiosError('Invalid proxy authorization', AxiosError.ERR_BAD_OPTION, { proxy });
       }
-      const base64 = Buffer
+
-        .from(proxy.auth, 'utf8')
+      const base64 = Buffer.from(proxy.auth, 'utf8').toString('base64');
-        .toString('base64');
+
       options.headers['Proxy-Authorization'] = 'Basic ' + base64;
     }
 

test/unit/adapters/http.js

@@ -1361,6 +1361,29 @@ describe('supports http with nodejs', function () {
     });
   });
 
+  describe('when invalid proxy options are provided', function () {
+    it('should throw error', function () {
+      const proxy = {
+        protocol: "http:",
+        host: "hostname.abc.xyz",
+        port: 3300,
+        auth: {
+          username: "",
+          password: "",
+        }
+      };
+
+      return axios.get('https://test-domain.abc', {proxy})
+        .then(function(){
+          assert.fail('Does not throw');
+        }, function (error) {
+          assert.strictEqual(error.message, 'Invalid proxy authorization');
+          assert.strictEqual(error.code, 'ERR_BAD_OPTION');
+          assert.deepStrictEqual(error.config.proxy, proxy);
+        })
+    });
+  });
+
   context('different options for direct proxy configuration (without env variables)', () => {
     const destination = 'www.example.com';