[Console] Add ability to regress the ProgressBar

James Halsall · James Halsall · commit ceecd0073bf9 · 2016-09-02T14:35:22.000+01:00
diff --git a/src/Symfony/Component/Console/Helper/ProgressBar.php b/src/Symfony/Component/Console/Helper/ProgressBar.php
@@ -339,14 +339,22 @@ public function start($max = null)
      * Advances the progress output X steps.
      *
      * @param int $step Number of steps to advance
-     *
-     * @throws LogicException
      */
     public function advance($step = 1)
     {
         $this->setProgress($this->step + $step);
     }
 
+    /**
+     * Regresses the progress output X steps.
+     *
+     * @param int $step Number of steps to regress
+     */
+    public function regress($step = 1)
+    {
+        $this->setProgress($this->step - $step);
+    }
+
     /**
      * Sets whether to overwrite the progressbar, false for new line.
      *
@@ -361,18 +369,15 @@ public function setOverwrite($overwrite)
      * Sets the current progress.
      *
      * @param int $step The current progress
-     *
-     * @throws LogicException
      */
     public function setProgress($step)
     {
         $step = (int) $step;
-        if ($step < $this->step) {
-            throw new LogicException('You can\'t regress the progress bar.');
-        }
 
         if ($this->max && $step > $this->max) {
             $this->max = $step;
+        } elseif ($step < 0) {
+            $step = 0;
         }
 
         $prevPeriod = (int) ($this->step / $this->redrawFreq);
diff --git a/src/Symfony/Component/Console/Tests/Helper/ProgressBarTest.php b/src/Symfony/Component/Console/Tests/Helper/ProgressBarTest.php
@@ -96,6 +96,77 @@ public function testAdvanceOverMax()
         );
     }
 
+    public function testRegress()
+    {
+        $bar = new ProgressBar($output = $this->getOutputStream());
+        $bar->start();
+        $bar->advance();
+        $bar->advance();
+        $bar->regress();
+
+        rewind($output->getStream());
+        $this->assertEquals(
+            '    0 [>---------------------------]'.
+            $this->generateOutput('    1 [->--------------------------]').
+            $this->generateOutput('    2 [-->-------------------------]').
+            $this->generateOutput('    1 [->--------------------------]'),
+            stream_get_contents($output->getStream())
+        );
+    }
+
+    public function testRegressWithStep()
+    {
+        $bar = new ProgressBar($output = $this->getOutputStream());
+        $bar->start();
+        $bar->advance(4);
+        $bar->advance(4);
+        $bar->regress(2);
+
+        rewind($output->getStream());
+        $this->assertEquals(
+            '    0 [>---------------------------]'.
+            $this->generateOutput('    4 [---->-----------------------]').
+            $this->generateOutput('    8 [-------->-------------------]').
+            $this->generateOutput('    6 [------>---------------------]'),
+            stream_get_contents($output->getStream())
+        );
+    }
+
+    public function testRegressMultipleTimes()
+    {
+        $bar = new ProgressBar($output = $this->getOutputStream());
+        $bar->start();
+        $bar->advance(3);
+        $bar->advance(3);
+        $bar->regress(1);
+        $bar->regress(2);
+
+        rewind($output->getStream());
+        $this->assertEquals(
+            '    0 [>---------------------------]'.
+            $this->generateOutput('    3 [--->------------------------]').
+            $this->generateOutput('    6 [------>---------------------]').
+            $this->generateOutput('    5 [----->----------------------]').
+            $this->generateOutput('    3 [--->------------------------]'),
+            stream_get_contents($output->getStream())
+        );
+    }
+
+    public function testRegressBelowMin()
+    {
+        $bar = new ProgressBar($output = $this->getOutputStream(), 10);
+        $bar->setProgress(1);
+        $bar->regress();
+        $bar->regress();
+
+        rewind($output->getStream());
+        $this->assertEquals(
+            '  1/10 [==>-------------------------]  10%'.
+            $this->generateOutput('  0/10 [>---------------------------]   0%'),
+            stream_get_contents($output->getStream())
+        );
+    }
+
     public function testFormat()
     {
         $expected =
@@ -282,18 +353,6 @@ public function testSetCurrentBeforeStarting()
         $this->assertNotNull($bar->getStartTime());
     }
 
-    /**
-     * @expectedException        \LogicException
-     * @expectedExceptionMessage You can't regress the progress bar
-     */
-    public function testRegressProgress()
-    {
-        $bar = new ProgressBar($output = $this->getOutputStream(), 50);
-        $bar->start();
-        $bar->setProgress(15);
-        $bar->setProgress(10);
-    }
-
     public function testRedrawFrequency()
     {
         $bar = $this->getMock('Symfony\Component\Console\Helper\ProgressBar', array('display'), array($this->getOutputStream(), 6));
