Update travis config, test php 8 versions, fix php 8 errors

.travis.yml

@@ -1,33 +1,36 @@
+# Test any changes here to see the impact - https://config.travis-ci.com/explore
+dist: bionic
 language: php
 
-sudo: false
-dist: trusty
+php:
+  - 7.4
+  - 8.0
 
 env:
   global:
     - setup=basic
-    - xdebug=true
+    - xdebug=false
+  jobs:
+    - LARAVEL_VERSION=8.*
 
 cache:
   directories:
     - $HOME/.composer/cache
 
-matrix:
-  include:
-    - php: 7.4
-      env: xdebug=false
-#    - php: 8.0
-#      env: xdebug=false
-#    - php: 8.1
-#      env: xdebug=false
-
 before_install:
   - if [[ $xdebug = 'true' ]] ; then phpenv config-rm xdebug.ini; fi
+  - composer self-update --2
 
 install:
   - if [[ $setup = 'basic' ]]; then travis_retry composer install --prefer-dist --no-interaction --no-suggest; fi
   - if [[ $setup = 'stable' ]]; then travis_retry composer update --prefer-dist --no-interaction --no-suggest --prefer-stable; fi
   - if [[ $setup = 'lowest' ]]; then travis_retry composer update --prefer-dist --no-interaction --no-suggest --prefer-stable --prefer-lowest; fi
 
+before_script:
+  - travis_retry composer install --prefer-source --no-interaction
+  - if [ "$LARAVEL_VERSION" != "" ]; then composer require --dev "illuminate/routing:${LARAVEL_VERSION}" --no-update; fi;
+  - if [ "$LARAVEL_VERSION" != "" ]; then composer require --dev "illuminate/support:${LARAVEL_VERSION}" --no-update; fi;
+  - composer update
+
 script:
   - vendor/bin/phpunit

src/Auth/Provider/Authorization.php

@@ -25,7 +25,7 @@ abstract class Authorization implements \Dingo\Api\Contract\Auth\Provider
      */
     public function validateAuthorizationHeader(Request $request)
     {
-        if (Str::startsWith(strtolower($request->headers->get('authorization')), $this->getAuthorizationMethod())) {
+        if (Str::startsWith(strtolower((string) $request->headers->get('authorization')), $this->getAuthorizationMethod())) {
             return true;
         }
 

src/Http/RateLimit/Handler.php

@@ -105,8 +105,8 @@ public function rateLimitRequest(Request $request, $limit = 0, $expires = 0)
         // limiting will not be imposed for the request.
         } else {
             $this->throttle = $this->getMatchingThrottles()->sort(function ($a, $b) {
-                return $a->getLimit() < $b->getLimit();
-            })->first();
+                return $a->getLimit() <=> $b->getLimit();
+            })->last();
         }
 
         if (is_null($this->throttle)) {

src/Routing/Router.php

@@ -470,7 +470,7 @@ protected function formatNamespace(array $new, array $old)
     protected function formatPrefix($new, $old)
     {
         if (isset($new['prefix'])) {
-            return trim(Arr::get($old, 'prefix'), '/').'/'.trim($new['prefix'], '/');
+            return trim((string) Arr::get($old, 'prefix'), '/').'/'.trim((string) $new['prefix'], '/');
         }
 
         return Arr::get($old, 'prefix', '');