SONARJAVA-6269 S1451 should correctly handle empty headerFormat

java-checks-test-sources/default/src/main/java/checks/FileHeaderCheck/ClassBlankLine.java

@@ -0,0 +1,7 @@
+
+package checks.FileHeaderCheck;
+
+public class ClassBlankLine {
+}
+// Compliant
+

java-checks-test-sources/default/src/main/java/checks/FileHeaderCheck/ClassDefaultHeader.java

@@ -0,0 +1,11 @@
+/*
+ * <Your-Product-Name>
+ * Copyright (c) <Year-From>-<Year-To> <Your-Company-Name>
+ *
+ * Please configure this header in your SonarCloud/SonarQube quality profile.
+ */
+package checks.FileHeaderCheck;
+
+public class ClassDefaultHeader {
+}
+// Compliant (default header)

java-checks-test-sources/default/src/main/java/checks/FileHeaderCheck/ClassNoBlankLine.java

@@ -0,0 +1,5 @@
+package checks.FileHeaderCheck;
+
+public class ClassNoBlankLine {
+}
+// Compliant

java-checks/src/main/java/org/sonar/java/checks/FileHeaderCheck.java

@@ -47,7 +47,6 @@ public class FileHeaderCheck extends IssuableSubscriptionVisitor {
     defaultValue = "false")
   public boolean isRegularExpression = false;
 
-  private String[] expectedLines;
   private Pattern searchPattern = null;
 
   @Override
@@ -58,18 +57,26 @@ public List<Tree.Kind> nodesToVisit() {
   @Override
   public void setContext(JavaFileScannerContext context) {
     super.context = context;
-    if (isRegularExpression) {
-      if (searchPattern == null) {
-        try {
-          searchPattern = Pattern.compile(getHeaderFormat(), Pattern.DOTALL);
-        } catch (IllegalArgumentException e) {
-          throw new IllegalArgumentException("[" + getClass().getSimpleName() + "] Unable to compile the regular expression: " + headerFormat, e);
-        }
+
+    if (headerFormat.isEmpty()) {
+      checkExpectedLines(new String[] {});
+      return;
+    }
+
+    if (!isRegularExpression) {
+      String[] expectedLines = headerFormat.split("(?:\r)?\n|\r");
+      checkExpectedLines(expectedLines);
+      return;
+    }
+
+    if (searchPattern == null) {
+      try {
+        searchPattern = Pattern.compile(getHeaderFormat(), Pattern.DOTALL);
+      } catch (IllegalArgumentException e) {
+        throw new IllegalArgumentException("[" + getClass().getSimpleName() + "] Unable to compile the regular expression: " + headerFormat, e);
       }
-    } else {
-      expectedLines = headerFormat.split("(?:\r)?\n|\r");
     }
-    visitFile();
+    checkRegularExpression(context.getFileContent());
   }
 
   private String getHeaderFormat() {
@@ -80,13 +87,9 @@ private String getHeaderFormat() {
     return format;
   }
 
-  private void visitFile() {
-    if (isRegularExpression) {
-      checkRegularExpression(context.getFileContent());
-    } else {
-      if (!matches(expectedLines, context.getFileLines())) {
-        addIssueOnFile(MESSAGE);
-      }
+  private void checkExpectedLines(String[] expectedLines) {
+    if (!matches(expectedLines, context.getFileLines())) {
+      addIssueOnFile(MESSAGE);
     }
   }
 
@@ -104,9 +107,9 @@ private static boolean matches(String[] expectedLines, List<String> lines) {
       result = true;
 
       Iterator<String> it = lines.iterator();
-      for (int i = 0; i < expectedLines.length; i++) {
+      for (String expectedLine : expectedLines) {
         String line = it.next();
-        if (!line.equals(expectedLines[i])) {
+        if (!line.equals(expectedLine)) {
           result = false;
           break;
         }

java-checks/src/test/java/org/sonar/java/checks/FileHeaderCheckTest.java

@@ -98,6 +98,26 @@ void test() {
       .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/Class3.java"))
       .withCheck(check)
       .verifyNoIssues();
+
+    check = new FileHeaderCheck();
+    check.headerFormat = "";
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/ClassBlankLine.java"))
+      .withCheck(check)
+      .verifyNoIssues();
+
+    check = new FileHeaderCheck();
+    check.headerFormat = "";
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/ClassNoBlankLine.java"))
+      .withCheck(check)
+      .verifyNoIssues();
+
+    check = new FileHeaderCheck();
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/ClassDefaultHeader.java"))
+      .withCheck(check)
+      .verifyNoIssues();
   }
 
   @Test
@@ -139,6 +159,22 @@ void regex() {
       .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/Regex4.java"))
       .withCheck(check)
       .verifyIssues();
+
+    check = new FileHeaderCheck();
+    check.headerFormat = "";
+    check.isRegularExpression = true;
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/ClassBlankLine.java"))
+      .withCheck(check)
+      .verifyNoIssues();
+
+    check = new FileHeaderCheck();
+    check.headerFormat = "";
+    check.isRegularExpression = true;
+    CheckVerifier.newVerifier()
+      .onFile(mainCodeSourcesPath("checks/FileHeaderCheck/ClassNoBlankLine.java"))
+      .withCheck(check)
+      .verifyNoIssues();
   }
 
   @Test

sonar-java-plugin/src/test/java/org/sonar/plugins/java/JavaSensorTest.java

@@ -429,8 +429,8 @@ void do_not_filter_checks_when_no_autoscan() throws IOException {
         "CustomRepository:CustomMainCheck",
         "CustomRepository:CustomJspCheck",
         "CustomRepository:CustomTestCheck",
-        // not in SonarWay (FileHeaderCheck)
-        "java:S1451",
+        // not in SonarWay (CatchUsesExceptionWithContextCheck)
+        "java:S1166",
         // main check in SonarWay (DefaultPackageCheck)
         "java:S1220",
         // main check in SonarWay, not supported by autoscan (CombineCatchCheck)