Group line code-coverage by branch

src/CodeCoverage.php

@@ -485,9 +485,14 @@ private function applyExecutableLinesFilter(RawCodeCoverageData $data): void
                 continue;
             }
 
+            $linesToBranchMap = $this->analyser()->executableLinesIn($filename);
             $data->keepLineCoverageDataOnlyForLines(
                 $filename,
-                $this->analyser()->executableLinesIn($filename)
+                array_keys($linesToBranchMap)
+            );
+            $data->markExecutableLineByBranch(
+                $filename,
+                $linesToBranchMap
             );
         }
     }

src/RawCodeCoverageData.php

@@ -91,7 +91,7 @@ public static function fromUncoveredFile(string $filename, FileAnalyser $analyse
     {
         $lineCoverage = [];
 
-        foreach ($analyser->executableLinesIn($filename) as $line) {
+        foreach ($analyser->executableLinesIn($filename) as $line => $branch) {
             $lineCoverage[$line] = Driver::LINE_NOT_EXECUTED;
         }
 
@@ -141,6 +141,42 @@ public function keepLineCoverageDataOnlyForLines(string $filename, array $lines)
         );
     }
 
+    /**
+     * @param int[] $linesToBranchMap
+     */
+    public function markExecutableLineByBranch(string $filename, array $linesToBranchMap): void
+    {
+        if (!isset($this->lineCoverage[$filename])) {
+            return;
+        }
+
+        $linesByBranch = [];
+
+        foreach ($linesToBranchMap as $line => $branch) {
+            $linesByBranch[$branch][] = $line;
+        }
+
+        foreach ($this->lineCoverage[$filename] as $line => $lineStatus) {
+            if (!isset($linesToBranchMap[$line])) {
+                continue;
+            }
+
+            $branch = $linesToBranchMap[$line];
+
+            if (!isset($linesByBranch[$branch])) {
+                continue;
+            }
+
+            foreach ($linesByBranch[$branch] as $lineInBranch) {
+                $this->lineCoverage[$filename][$lineInBranch] = $lineStatus;
+            }
+
+            if (Driver::LINE_EXECUTED === $lineStatus) {
+                unset($linesByBranch[$branch]);
+            }
+        }
+    }
+
     /**
      * @param int[] $lines
      */