Unit tests for the exponential backoff mechanism

README.md

@@ -535,6 +535,10 @@ A full suite of unit tests is in the works. Assuming you've installed `php-gds`
 ```bash
 vendor/bin/phpunit
 ```
+Or, if you need to run containerised tests, you can use the `runphp` image (or any you choose)
+```bash
+docker run --rm -it -v`pwd`:/app -w /app fluentthinking/runphp:7.4.33-v0.9.0 php /app/vendor/bin/phpunit
+```
 
 [Click here for more details](tests/).
 

tests/BackoffTest.php

@@ -0,0 +1,134 @@
+<?php
+/**
+ * Copyright 2023 Tom Walder
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Tests for exponential backoff
+ *
+ * @author Tom Walder <[email protected]>
+ */
+class BackoffTest extends \PHPUnit\Framework\TestCase
+{
+    public function testOnceAndReturn()
+    {
+        \GDS\Gateway::exponentialBackoff(true);
+        $shouldBeCalled = $this->getMockBuilder(\stdClass::class)
+            ->addMethods(['__invoke'])
+            ->getMock();
+        $shouldBeCalled->expects($this->once())
+            ->method('__invoke')
+            ->willReturn(87);
+        $int_result = $this->buildTestGateway()->runExecuteWithExponentialBackoff($shouldBeCalled);
+        $this->assertEquals(87, $int_result);
+    }
+
+    public function testBackoffCount()
+    {
+        \GDS\Gateway::exponentialBackoff(true);
+        $shouldBeCalled = $this->getMockBuilder(\stdClass::class)
+            ->addMethods(['__invoke'])
+            ->getMock();
+        $shouldBeCalled->expects($this->exactly(\GDS\Gateway::RETRY_MAX_ATTEMPTS))
+            ->method('__invoke')
+            ->willThrowException(new \RuntimeException('Test Exception', 503));
+        $this->expectException(\RuntimeException::class);
+        $this->buildTestGateway()->runExecuteWithExponentialBackoff($shouldBeCalled);
+    }
+
+    public function testBackoffCountDisabled()
+    {
+        \GDS\Gateway::exponentialBackoff(false);
+        $shouldBeCalled = $this->getMockBuilder(\stdClass::class)
+            ->addMethods(['__invoke'])
+            ->getMock();
+        $shouldBeCalled->expects($this->once())
+            ->method('__invoke')
+            ->willThrowException(new \RuntimeException('Not retried', 503));
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Not retried');
+        $this->expectExceptionCode(503);
+        $this->buildTestGateway()->runExecuteWithExponentialBackoff($shouldBeCalled);
+    }
+
+    public function testPartialBackoff() {
+        \GDS\Gateway::exponentialBackoff(true);
+        $int_calls = 0;
+        $shouldBeCalled = function () use (&$int_calls) {
+            $int_calls++;
+            if ($int_calls < 4) {
+                throw new \RuntimeException('Always caught', 503);
+            }
+            return 42;
+        };
+        $int_result = $this->buildTestGateway()->runExecuteWithExponentialBackoff($shouldBeCalled);
+        $this->assertEquals(42, $int_result);
+        $this->assertEquals(4, $int_calls);
+    }
+
+
+    public function testIgnoredExceptionClass()
+    {
+        \GDS\Gateway::exponentialBackoff(true);
+        $shouldBeCalled = $this->getMockBuilder(\stdClass::class)
+            ->addMethods(['__invoke'])
+            ->getMock();
+        $shouldBeCalled->expects($this->once())
+            ->method('__invoke')
+            ->willThrowException(new \LogicException('Ignored', 503));
+        $this->expectException(\LogicException::class);
+        $this->expectExceptionMessage('Ignored');
+        $this->expectExceptionCode(503);
+        $this->buildTestGateway()->runExecuteWithExponentialBackoff(
+            $shouldBeCalled,
+            \RuntimeException::class
+        );
+    }
+
+    public function testIgnoredExceptionCode()
+    {
+        \GDS\Gateway::exponentialBackoff(true);
+        $shouldBeCalled = $this->getMockBuilder(\stdClass::class)
+            ->addMethods(['__invoke'])
+            ->getMock();
+        $shouldBeCalled->expects($this->once())
+            ->method('__invoke')
+            ->willThrowException(new \RuntimeException('Non-retry code', 42));
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Non-retry code');
+        $this->expectExceptionCode(42);
+        $this->buildTestGateway()->runExecuteWithExponentialBackoff($shouldBeCalled);
+    }
+
+    public function testRetryOnce()
+    {
+        \GDS\Gateway::exponentialBackoff(true);
+        $int_calls = 0;
+        $shouldBeCalled = function () use (&$int_calls) {
+            $int_calls++;
+            throw new \RuntimeException('Once', 500);
+        };
+        $this->expectException(\RuntimeException::class);
+        $this->expectExceptionMessage('Once');
+        $this->expectExceptionCode(500);
+        $this->buildTestGateway()->runExecuteWithExponentialBackoff($shouldBeCalled);
+        $this->assertEquals(2, $int_calls);
+    }
+
+    private function buildTestGateway(): \RESTv1GatewayBackoff
+    {
+        return new RESTv1GatewayBackoff('dataset-id', 'my-app');
+    }
+}

tests/base/RESTv1GatewayBackoff.php

@@ -0,0 +1,13 @@
+<?php
+
+class RESTv1GatewayBackoff extends \GDS\Gateway\RESTv1
+{
+
+    public function runExecuteWithExponentialBackoff(
+        callable $fnc_main,
+        string $str_exception = null,
+        callable $fnc_resolve_exception = null
+    ) {
+        return $this->executeWithExponentialBackoff($fnc_main, $str_exception, $fnc_resolve_exception);
+    }
+}

tests/bootstrap.php

@@ -12,7 +12,8 @@
 require_once(dirname(__FILE__) . '/../vendor/autoload.php');
 
 // Base Test Files
+require_once(dirname(__FILE__) . '/base/RESTv1GatewayBackoff.php');
 require_once(dirname(__FILE__) . '/base/RESTv1Test.php');
 require_once(dirname(__FILE__) . '/base/Simple.php');
 require_once(dirname(__FILE__) . '/base/Book.php');
-require_once(dirname(__FILE__) . '/base/FakeGuzzleClient.php');
+require_once(dirname(__FILE__) . '/base/FakeGuzzleClient.php');