Start adding basic branch coverage requirements

Author: jmrieger

src/CodeCoverage.php

@@ -133,6 +133,11 @@ final class CodeCoverage
      */
     private $report;
 
+    /**
+     * @var bool
+     */
+    private $determineBranchCoverage;
+
     /**
      * @throws RuntimeException
      */
@@ -458,6 +463,23 @@ public function setUnintentionallyCoveredSubclassesWhitelist(array $whitelist):
         $this->unintentionallyCoveredSubclassesWhitelist = $whitelist;
     }
 
+    /**
+     * Specify whether branch coverage should be processed, if the chosen driver supports branch coverage
+     * Branch coverage is only supported for the Xdebug driver, with an xdebug version of >= 2.3.2
+     */
+    public function setDetermineBranchCoverage(bool $flag): void
+    {
+        if ($flag) {
+            if ($this->driver instanceof Xdebug && \version_compare(\phpversion('xdebug'), '2.3.2', '>=')) {
+                $this->determineBranchCoverage = $flag;
+            } else {
+                throw new RuntimeException('Branch coverage requires Xdebug version 2.3.2 or newer');
+            }
+        } else {
+            $this->determineBranchCoverage = false;
+        }
+    }
+
     /**
      * Determine the priority for a line
      *

src/Driver/Driver.php

@@ -44,4 +44,9 @@ public function start(bool $determineUnusedAndDead = true): void;
      * Stop collection of code coverage information.
      */
     public function stop(): array;
+
+    /**
+     * Specify that branch coverage should be included with collected code coverage information.
+     */
+    public function setDetermineBranchCoverage(bool $flag): void;
 }

src/Driver/PHPDBG.php

@@ -76,6 +76,14 @@ public function stop(): array
         return $this->detectExecutedLines($fetchedLines, $dbgData);
     }
 
+    /**
+     * Specify that branch coverage should be included with collected code coverage information.
+     */
+    public function setDetermineBranchCoverage(bool $flag): void
+    {
+        throw new RuntimeException('Branch coverage is not supported in PHPDBG');
+    }
+
     /**
      * Convert phpdbg based data into the format CodeCoverage expects
      */

src/Driver/Xdebug.php

@@ -23,6 +23,11 @@ final class Xdebug implements Driver
      */
     private $cacheNumLines = [];
 
+    /**
+     * @var bool
+     */
+    private $determineBranchCoverage = false;
+
     /**
      * @throws RuntimeException
      */
@@ -42,11 +47,16 @@ public function __construct()
      */
     public function start(bool $determineUnusedAndDead = true): void
     {
+        $flag = 0;
+
         if ($determineUnusedAndDead) {
-            \xdebug_start_code_coverage(XDEBUG_CC_UNUSED | XDEBUG_CC_DEAD_CODE);
-        } else {
-            \xdebug_start_code_coverage();
+            $flag = XDEBUG_CC_UNUSED | XDEBUG_CC_DEAD_CODE;
+        }
+
+        if ($this->determineBranchCoverage) {
+            $flag |= XDEBUG_CC_BRANCH_CHECK;
         }
+        \xdebug_start_code_coverage($flag);
     }
 
     /**
@@ -61,6 +71,17 @@ public function stop(): array
         return $this->cleanup($data);
     }
 
+    /**
+     * Specify that branch coverage should be included with collected code coverage information.
+     */
+    public function setDetermineBranchCoverage(bool $flag): void
+    {
+        if ($flag && \version_compare(\phpversion('xdebug'), '2.3.2', '<')) {
+            throw new RuntimeException('Branch coverage requires Xdebug 2.3.2 or newer');
+        }
+        $this->determineBranchCoverage = $flag;
+    }
+
     private function cleanup(array $data): array
     {
         foreach (\array_keys($data) as $file) {