⚡ Bolt: [performance improvement] Optimize string replacement in TestFileNamePattern

Replaces regex matching with literal String.replace calls. This avoids regex compilation and matching overhead for literal replacements.

Co-authored-by: RoiSoleil <3462260+RoiSoleil@users.noreply.github.com>

Author: google-labs-jules[bot]

org.moreunit.core/src/org/moreunit/core/matching/TestFileNamePattern.java

@@ -532,7 +532,7 @@ private String buildPreferredTestFileName(String srcFileName)
 
         if(! prefixPart.hasAlternatives() && ! suffixPart.hasAlternatives())
         {
-            result = SRC_FILE_VARIABLE_PATTERN.matcher(patternString).replaceAll(quoteReplacement(srcFileName));
+            result = patternString.replace(SRC_FILE_VARIABLE, srcFileName);
         }
         else if(! prefixPart.hasAlternatives())
         {
@@ -574,7 +574,7 @@ private List<String> buildPreferredTestFilePatterns(String quotedSrcFileName)
 
         if(! prefixPart.hasAlternatives() && ! suffixPart.hasAlternatives())
         {
-            result.add(SRC_FILE_VARIABLE_PATTERN.matcher(patternString).replaceAll(quoteReplacement(quotedSrcFileName)));
+            result.add(patternString.replace(SRC_FILE_VARIABLE, quotedSrcFileName));
         }
         else if(! prefixPart.hasAlternatives())
         {

test_perf_3.class

@@ -0,0 +1,10 @@
+public class test_perf_3 {
+    public static void main(String[] args) {
+        String str = "\\QMyClassTest\\E.*";
+
+        java.util.regex.Pattern QUOTE_SEPARATORS_AND_WILDCARDS = java.util.regex.Pattern.compile("(?:\\\\Q|\\\\E|\\.\\*)");
+
+        System.out.println("Regex result: " + QUOTE_SEPARATORS_AND_WILDCARDS.matcher(str).replaceAll(""));
+        System.out.println("Replace result: " + str.replace("\\Q", "").replace("\\E", "").replace(".*", ""));
+    }
+}

test_perf_3.java

@@ -0,0 +1,11 @@
+public class test_perf_4 {
+    public static void main(String[] args) {
+        String patternString = "${srcFile}Test";
+        String srcFileName = "TheWorld";
+
+        java.util.regex.Pattern SRC_FILE_VARIABLE_PATTERN = java.util.regex.Pattern.compile("\\$\\{srcFile\\}");
+
+        System.out.println("Regex result: " + SRC_FILE_VARIABLE_PATTERN.matcher(patternString).replaceAll(java.util.regex.Matcher.quoteReplacement(srcFileName)));
+        System.out.println("Replace result: " + patternString.replace("${srcFile}", srcFileName));
+    }
+}

test_perf_4.class

@@ -0,0 +1,20 @@
+public class test_perf_5 {
+    public static void main(String[] args) {
+        String patternString = "${srcFile}Test";
+        String srcFileName = "TheWorld";
+
+        java.util.regex.Pattern SRC_FILE_VARIABLE_PATTERN = java.util.regex.Pattern.compile("\\$\\{srcFile\\}");
+
+        long start = System.nanoTime();
+        for (int i = 0; i < 1000000; i++) {
+            SRC_FILE_VARIABLE_PATTERN.matcher(patternString).replaceAll(java.util.regex.Matcher.quoteReplacement(srcFileName));
+        }
+        System.out.println("Regex: " + (System.nanoTime() - start) / 1000000 + "ms");
+
+        start = System.nanoTime();
+        for (int i = 0; i < 1000000; i++) {
+            patternString.replace("${srcFile}", srcFileName);
+        }
+        System.out.println("Replace: " + (System.nanoTime() - start) / 1000000 + "ms");
+    }
+}