SONARPY-1285 Fix FP on S1451 when shebang head lines are used (SonarSource#1446)

Author: maksim-grebeniuk-sonarsource

python-checks/src/main/java/org/sonar/python/checks/FileHeaderCopyrightCheck.java

@@ -19,8 +19,8 @@
  */
 package org.sonar.python.checks;
 
-import java.util.regex.Matcher;
 import java.util.regex.Pattern;
+import java.util.stream.Stream;
 import org.sonar.check.Rule;
 import org.sonar.check.RuleProperty;
 import org.sonar.plugins.python.api.PythonSubscriptionCheck;
@@ -48,6 +48,7 @@ public class FileHeaderCopyrightCheck extends PythonSubscriptionCheck {
     defaultValue = "false")
   public boolean isRegularExpression = false;
   private Pattern searchPattern = null;
+  private Pattern shebangPattern = Pattern.compile("^#![^\\n]+\\n", Pattern.MULTILINE);
 
   @Override
   public void initialize(Context context) {
@@ -60,12 +61,16 @@ public void initialize(Context context) {
         }
       }
 
-      String retrievedText = getHeaderText(ctx);
+      var header = getHeaderText(ctx);
+      var headerWithoutShebang = shebangPattern.matcher(header).replaceFirst("");
 
       if (isRegularExpression) {
-        checkRegularExpression(ctx, retrievedText);
-      } else {
-        if (!headerFormat.isEmpty() && !retrievedText.startsWith(headerFormat)) {
+        checkRegularExpression(ctx, header, headerWithoutShebang);
+      } else if (!headerFormat.isEmpty()) {
+        var matches = Stream.of(header, headerWithoutShebang)
+          .anyMatch(h -> h.startsWith(headerFormat));
+
+        if (!matches) {
           ctx.addFileIssue(MESSAGE);
         }
       }
@@ -80,9 +85,12 @@ private static String getHeaderText(SubscriptionContext ctx) {
     return ctx.pythonFile().content();
   }
 
-  private void checkRegularExpression(SubscriptionContext ctx, String fileContent) {
-    Matcher matcher = searchPattern.matcher(fileContent);
-    if (!matcher.find() || matcher.start() != 0) {
+  private void checkRegularExpression(SubscriptionContext ctx, String... fileContent) {
+    var matches = Stream.of(fileContent)
+      .map(searchPattern::matcher)
+      .anyMatch(matcher -> matcher.find() && matcher.start() == 0);
+
+    if (!matches) {
       ctx.addFileIssue(MESSAGE);
     }
   }

python-checks/src/test/java/org/sonar/python/checks/FileHeaderCopyrightCheckTest.java

@@ -141,4 +141,22 @@ public void test_searchPattern_exception() {
     IllegalArgumentException e = Assert.assertThrows(IllegalArgumentException.class, () -> SubscriptionVisitor.analyze(check, context));
     Assertions.assertThat(e.getMessage()).isEqualTo("[FileHeaderCopyrightCheck] Unable to compile the regular expression: "+fileHeaderCopyrightCheck.headerFormat);
   }
+
+  @Test
+  public void shebangTest() {
+    var fileHeaderCopyrightCheck = new FileHeaderCopyrightCheck();
+    fileHeaderCopyrightCheck.headerFormat = "# Copyright FOO\n";
+    PythonCheckVerifier.verifyNoIssue("src/test/resources/checks/fileHeaderCopyright/shebangCopyright.py", fileHeaderCopyrightCheck);
+  }
+
+  @Test
+  public void shebangPatternTest() {
+    var fileHeaderCopyrightCheck = new FileHeaderCopyrightCheck();
+    fileHeaderCopyrightCheck.isRegularExpression = true;
+    fileHeaderCopyrightCheck.headerFormat = "# Copyright[ ]20[0-9]{2}";
+    PythonCheckVerifier.verifyNoIssue("src/test/resources/checks/fileHeaderCopyright/searchPatternShebangCopyright.py",
+      fileHeaderCopyrightCheck);
+    PythonCheckVerifier.verify("src/test/resources/checks/fileHeaderCopyright/searchPatternShebangCopyrightNonCompliant.py",
+      fileHeaderCopyrightCheck);
+  }
 }

python-checks/src/test/resources/checks/fileHeaderCopyright/searchPatternShebangCopyright.py

@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+# Copyright 2020
+# All rights reserved.
+
+def foo():
+    pass

python-checks/src/test/resources/checks/fileHeaderCopyright/searchPatternShebangCopyrightNonCompliant.py

@@ -0,0 +1,6 @@
+#!/usr/bin/env python3
+# Copyright_2020
+# All rights reserved.
+# Noncompliant@-4
+def foo():
+    pass

python-checks/src/test/resources/checks/fileHeaderCopyright/shebangCopyright.py

@@ -0,0 +1,11 @@
+#!/usr/bin/env python3
+# Copyright FOO
+
+def fun():
+  if expression:
+    pass
+  if expression:
+    pass
+  if expression:
+    pass
+  return