Introduce merge_junit script (#103)

* Introduce `merge_junit` script

To improve performance of Android unit tests collection. Originated it woocommerce/woocommerce-android#12064

* Add changelog entry

* Address SC2129

Consider using { cmd1; cmd2; } >> file instead of individual redirects. https://www.shellcheck.net/wiki/SC2129

* Remove `sh` suffix

To align to other commands

* Create output file before saving data there

* Rename script to `merge_junit_reports`

* Remove `<testsuites>` tag if it's present in any report that is about to be merged

* Update CHANGELOG.md

Co-authored-by: Olivier Halligon <[email protected]>

---------

Co-authored-by: Olivier Halligon <[email protected]>

CHANGELOG.md

@@ -38,7 +38,7 @@ _None._
 
 ### New Features
 
-_None._
+- Introduce `merge_junit_reports` script [#103]
 
 ### Bug Fixes
 

bin/merge_junit_reports

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+# Initialize variables
+reports_dir=""
+output_file=""
+
+# Function to show usage
+usage() {
+    echo "Usage: $0 -d <reports_dir> -o <output_file>"
+    exit 1
+}
+
+# Parse command-line options
+while getopts "d:o:" opt; do
+    case $opt in
+        d) reports_dir=$OPTARG ;;
+        o) output_file=$OPTARG ;;
+        ?) usage ;;
+    esac
+done
+
+# Check if both arguments were provided
+if [ -z "$reports_dir" ] || [ -z "$output_file" ]; then
+    usage
+fi
+
+touch "$output_file"
+{
+  echo '<?xml version="1.0" encoding="UTF-8"?>'
+  # Write XML header to the output file
+  echo '<testsuites>'
+
+  # Merge the content of all input JUnit files in the directory.
+  # Ignore <testsuites> tag in reports that are being merged,
+  # as this tag should be a top-level, root tag for any report
+  sed '/<\?xml .*\?>/d;/<testsuites.*>/d; /<\/testsuites>/d' "$reports_dir"/*.xml
+
+  # Close the testsuites tag
+  echo '</testsuites>'
+} >> "$output_file"
+
+# Print the result
+echo "Merged XML reports into $output_file"