SONARPY-2081: Array index in hex form should be handled correctly (#2055)

* SONARPY-2081 parse hex literals correctly

* SONARPY-2081 add test case

Author: Seppli11

python-checks/src/test/resources/checks/useStartsWithEndsWithCheck.py

@@ -58,6 +58,7 @@ def f():
   foobar[10:] == 'bar' # Noncompliant
 
   foobar[3:6:1] == 'bar' # Compliant: Too much potential for FPs with step sizes != 1, too early stop indices, etc.
+  foobar[3:6:0x1] == 'bar' # Same
   foobar[-3:] == 'bar' # Noncompliant {{Use `endswith` here.}}
   foobar[:-3] == 'foo' # Noncompliant {{Use `startswith` here.}}
 
@@ -94,3 +95,4 @@ def __index__(self):
 
   foobar[:3:2] == 'fo' # Compliant: This is not a simple step 1 slice, not a prefix, or suffix, so the rule does not apply
   foobar[:3:-2] == 'r' # Same
+

python-frontend/src/main/java/org/sonar/python/tree/NumericLiteralImpl.java

@@ -62,6 +62,8 @@ public long valueAsLong() {
     }
     if (literalValue.startsWith("0o") || literalValue.startsWith("0O")) {
       return Integer.valueOf(literalValue.substring(2), 8);
+    } else if (literalValue.startsWith("0x") || literalValue.startsWith("0X")) {
+      return Integer.valueOf(literalValue.substring(2), 16);
     } else if (literalValue.startsWith("0") && literalValue.length() > 1) {
       // Python 2 syntax (https://www.python.org/dev/peps/pep-3127/#removal-of-old-octal-syntax)
       return Integer.valueOf(literalValue.substring(1), 8);

python-frontend/src/test/java/org/sonar/python/tree/PythonTreeMakerTest.java

@@ -2019,6 +2019,8 @@ void numeric_literal_expression() {
     testNumericLiteral("0o777", 511L);
     testNumericLiteral("0O777", 511L);
     testNumericLiteral("0777", 511L);
+    testNumericLiteral("0x28", 0x28L);
+    testNumericLiteral("0X28", 0x28L);
   }
 
   private void testNumericLiteral(String code, Long expectedValue) {