Merge pull request #19 from yamadashy/fix/exponential-strategy

Fix ExponentialStrategy calculation and update tests

src/Strategies/ExponentialStrategy.php

@@ -14,9 +14,6 @@ class ExponentialStrategy extends AbstractStrategy
      */
     public function getWaitTime($attempt)
     {
-        return (int) ($attempt == 1
-            ? $this->base
-            : pow(2, $attempt) * $this->base
-        );
+        return (int) ($this->base * (pow(2, $attempt - 1)));
     }
 }

tests/Strategies/ExponentialStrategyTest.php

@@ -17,12 +17,21 @@ public function testWaitTimes()
         $s = new ExponentialStrategy(200);
 
         $this->assertEquals(200, $s->getWaitTime(1));
-        $this->assertEquals(800, $s->getWaitTime(2));
-        $this->assertEquals(1600, $s->getWaitTime(3));
-        $this->assertEquals(3200, $s->getWaitTime(4));
-        $this->assertEquals(6400, $s->getWaitTime(5));
-        $this->assertEquals(12800, $s->getWaitTime(6));
-        $this->assertEquals(25600, $s->getWaitTime(7));
-        $this->assertEquals(51200, $s->getWaitTime(8));
+        $this->assertEquals(400, $s->getWaitTime(2));
+        $this->assertEquals(800, $s->getWaitTime(3));
+        $this->assertEquals(1600, $s->getWaitTime(4));
+        $this->assertEquals(3200, $s->getWaitTime(5));
+        $this->assertEquals(6400, $s->getWaitTime(6));
+        $this->assertEquals(12800, $s->getWaitTime(7));
+        $this->assertEquals(25600, $s->getWaitTime(8));
+    }
+
+    public function testWaitTimesWithDefault()
+    {
+        $strategy = new ExponentialStrategy();
+        $base = $strategy->getBase();
+        $this->assertEquals((int) ($base * pow(2, 0)), $strategy->getWaitTime(1));
+        $this->assertEquals((int) ($base * pow(2, 1)), $strategy->getWaitTime(2));
+        $this->assertEquals((int) ($base * pow(2, 2)), $strategy->getWaitTime(3));
     }
 }