allow to silence exceptions when exponential backoff disabled

Crowdstar · Mar 24, 2021 · 29b63fb · 29b63fb
1 parent 26310e6
commit 29b63fb
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Showing 2 changed files with 68 additions and 37 deletions.
diff --git a/src/ExponentialBackoff.php b/src/ExponentialBackoff.php
@@ -33,6 +33,8 @@
  */
 class ExponentialBackoff
 {
+    public const DEFAULT_MAX_ATTEMPTS = 4;
+
     public const TYPE_MICROSECONDS = 1;
     public const TYPE_SECONDS      = 2;
 
@@ -54,7 +56,7 @@ class ExponentialBackoff
     /**
      * @var int
      */
-    protected $maxAttempts = 4;
+    protected $maxAttempts = self::DEFAULT_MAX_ATTEMPTS;
 
     /**
      * @var int
@@ -176,17 +178,17 @@ public function setRetryCondition(AbstractRetryCondition $retryCondition): self
      */
     protected function retry($result, ?\Exception $e): bool
     {
-        if ($this->getCurrentAttempts() < $this->getMaxAttempts()) {
-            if ($this->getRetryCondition()->met($result, $e)) {
-                return false;
-            }
-
-            $this->sleep();
+        if ($this->getRetryCondition()->met($result, $e)) {
+            return false;
+        }
 
-            return true;
+        if ($this->getCurrentAttempts() >= $this->getMaxAttempts()) {
+            return false;
         }
 
-        return false;
+        $this->sleep();
+
+        return true;
     }
 
     /**

diff --git a/tests/unit/CustomizedConditionTest.php b/tests/unit/CustomizedConditionTest.php
@@ -32,32 +32,40 @@
  */
 class CustomizedConditionTest extends TestCase
 {
+    protected const MAX_ATTEMPTS = ExponentialBackoff::DEFAULT_MAX_ATTEMPTS;
+
+    public function dataBackoff(): array
+    {
+        return [
+            [
+                'maxAttempts' => 1,
+                'message'     => 'Maximum # of attempts is 1 (exponential backoff disabled)',
+            ],
+            [
+                'maxAttempts' => 2,
+                'message'     => 'Maximum # of attempts is 2',
+            ],
+            [
+                'maxAttempts' => self::MAX_ATTEMPTS,
+                'message'     => 'Maximum # of attempts is 4',
+            ],
+        ];
+    }
+
     /**
      * The $backoff object in this test is the same as the one in the next method self::testUnthrowableException(),
      * except that method $backoff->throwable() returns TRUE.
      *
+     * @dataProvider dataBackoff
      * @covers \CrowdStar\Backoff\AbstractRetryCondition::throwable()
      * @covers \CrowdStar\Backoff\ExponentialBackoff::run()
      */
-    public function testThrowableException()
+    public function testThrowableException(int $maxAttempts)
     {
-        $helper  = (new Helper())->setException(Exception::class)->setExpectedFailedAttempts(4);
-        $backoff = (new ExponentialBackoff(
-            new class extends AbstractRetryCondition {
-                public function throwable(): bool
-                {
-                    // This tells the caller to throw out the exception when finally failed.
-                    return true;
-                }
-                public function met($result, ?Exception $e): bool
-                {
-                    return (empty($e) || (!($e instanceof Exception)));
-                }
-            }
-        ));
+        $helper = (new Helper())->setException(Exception::class)->setExpectedFailedAttempts(self::MAX_ATTEMPTS);
 
         $this->expectException(Exception::class); // Next function call will through out an exception.
-        $backoff->run(
+        $this->getBackoff($maxAttempts, false)->run(
             function () use ($helper) {
                 return $helper->getValueAfterExpectedNumberOfFailedAttemptsWithExceptionsThrownOut();
             }
@@ -68,31 +76,52 @@ function () use ($helper) {
      * The $backoff object in this test is the same as the one in the previous method self::testThrowableException(),
      * except that method $backoff->throwable() returns FALSE.
      *
+     * @dataProvider dataBackoff
      * @covers \CrowdStar\Backoff\AbstractRetryCondition::throwable()
      * @covers \CrowdStar\Backoff\ExponentialBackoff::run()
      */
-    public function testUnthrowableException()
+    public function testUnthrowableException(int $maxAttempts)
+    {
+        $helper = (new Helper())->setException(Exception::class)->setExpectedFailedAttempts(self::MAX_ATTEMPTS);
+        $this->getBackoff($maxAttempts, true)->run(
+            function () use ($helper) {
+                return $helper->getValueAfterExpectedNumberOfFailedAttemptsWithExceptionsThrownOut();
+            }
+        );
+
+        $this->addToAssertionCount(1); // Since there is no assertions in this test, we manually add the count by 1.
+    }
+
+    /**
+     * @param bool $silenceWhenFailed To hide or throw out the exception when finally failed.
+     */
+    protected function getBackoff(int $maxAttempts, bool $silenceWhenFailed): ExponentialBackoff
     {
-        $helper  = (new Helper())->setException(Exception::class)->setExpectedFailedAttempts(4);
         $backoff = (new ExponentialBackoff(
-            new class extends AbstractRetryCondition {
+            new class($silenceWhenFailed) extends AbstractRetryCondition {
+                protected $silenceWhenFailed;
+                protected $throwable = true;
+                public function __construct(bool $silenceWhenFailed)
+                {
+                    $this->silenceWhenFailed = $silenceWhenFailed;
+                }
                 public function throwable(): bool
                 {
-                    // This tells the caller NOT to throw out the exception when finally failed.
-                    return false;
+                    // This tells the caller to hide or throw out the exception when finally failed.
+                    return $this->throwable;
                 }
                 public function met($result, ?Exception $e): bool
                 {
-                    return (empty($e) || (!($e instanceof Exception)));
+                    if (empty($e) || (!($e instanceof Exception))) {
+                        return true;
+                    }
+                    $this->throwable = !$this->silenceWhenFailed;
+                    return false;
                 }
             }
         ));
+        $backoff->setMaxAttempts($maxAttempts);
 
-        $this->addToAssertionCount(1); // Since there is no assertions in this test, we manually add the count by 1.
-        $backoff->run(
-            function () use ($helper) {
-                return $helper->getValueAfterExpectedNumberOfFailedAttemptsWithExceptionsThrownOut();
-            }
-        );
+        return $backoff;
     }
 }