SONARPY-2070 Fix NPE when type inference visit is missing (#1928)

Author: maksim-grebeniuk-sonarsource

python-frontend/src/main/java/org/sonar/python/semantic/v2/types/TrivialTypeInferenceVisitor.java

@@ -353,6 +353,7 @@ public void visitImportFrom(ImportFrom importFrom) {
   @Override
   public void visitAssignmentStatement(AssignmentStatement assignmentStatement) {
     scan(assignmentStatement.assignedValue());
+    scan(assignmentStatement.lhsExpressions());
     Optional.of(assignmentStatement)
       .map(AssignmentStatement::lhsExpressions)
       .filter(lhs -> lhs.size() == 1)

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

@@ -44,7 +44,7 @@ public class ComprehensionExpressionImpl extends PyTree implements Comprehension
   private final ComprehensionFor comprehensionFor;
   private final Token closingToken;
   private Set<Symbol> symbols = new HashSet<>();
-  private PythonType pythonType;
+  private PythonType pythonType = PythonType.UNKNOWN;
 
   public ComprehensionExpressionImpl(Kind kind, @Nullable Token openingToken, Expression resultExpression,
                                      ComprehensionFor compFor, @Nullable Token closingToken) {

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

@@ -44,7 +44,7 @@ public class DictCompExpressionImpl extends PyTree implements DictCompExpression
   private final ComprehensionFor comprehensionFor;
   private final Token closingBrace;
   private Set<Symbol> symbols = new HashSet<>();
-  private PythonType pythonType;
+  private PythonType pythonType = PythonType.UNKNOWN;
 
   public DictCompExpressionImpl(Token openingBrace, Expression keyExpression, Token colon, Expression valueExpression,
                                 ComprehensionFor compFor, Token closingBrace) {

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

@@ -36,7 +36,7 @@ public class ListLiteralImpl extends PyTree implements ListLiteral {
   private final ExpressionList elements;
   private final Token rightBracket;
 
-  private PythonType typeV2;
+  private PythonType typeV2 = PythonType.UNKNOWN;
 
   public ListLiteralImpl(Token leftBracket, ExpressionList elements, Token rightBracket) {
     this.leftBracket = leftBracket;

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

@@ -31,7 +31,7 @@
 
 public class NoneExpressionImpl extends PyTree implements NoneExpression {
   private final Token none;
-  PythonType pythonType;
+  PythonType pythonType = PythonType.UNKNOWN;
 
   public NoneExpressionImpl(Token none) {
     this.none = none;

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

@@ -36,7 +36,7 @@ public class NumericLiteralImpl extends PyTree implements NumericLiteral {
   private final Token token;
   private final InferredType type;
 
-  private PythonType typeV2;
+  private PythonType typeV2 = PythonType.UNKNOWN;
 
   NumericLiteralImpl(Token token) {
     this.token = token;

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

@@ -37,7 +37,7 @@ public class StringLiteralImpl extends PyTree implements StringLiteral {
 
   private final List<StringElement> stringElements;
   private static final Set<String> BYTES_PREFIXES = new HashSet<>(Arrays.asList("b", "B", "br", "Br", "bR", "BR", "rb", "rB", "Rb", "RB"));
-  private PythonType typeV2;
+  private PythonType typeV2 = PythonType.UNKNOWN;
 
   StringLiteralImpl(List<StringElement> stringElements) {
     this.stringElements = stringElements;

python-frontend/src/test/java/org/sonar/python/semantic/v2/TypeInferenceV2Test.java

@@ -48,6 +48,7 @@
 import org.sonar.plugins.python.api.tree.RegularArgument;
 import org.sonar.plugins.python.api.tree.Statement;
 import org.sonar.plugins.python.api.tree.StatementList;
+import org.sonar.plugins.python.api.tree.StringLiteral;
 import org.sonar.plugins.python.api.tree.Tree;
 import org.sonar.python.PythonTestUtils;
 import org.sonar.python.semantic.ClassSymbolImpl;
@@ -2329,6 +2330,20 @@ def foo():
     Assertions.assertThat(fType).isSameAs(PythonType.UNKNOWN);
   }
 
+  @Test
+  void assignmentStatementLhsTypeTest() {
+    var fileInput = inferTypes("""
+      def foo():
+          subscription[call('goal_{}'.format(1))] = 1
+      """);
+
+    var literal = TreeUtils.firstChild(fileInput, StringLiteral.class::isInstance)
+      .map(StringLiteral.class::cast)
+      .get();
+
+    var type = literal.typeV2();
+    Assertions.assertThat(type.unwrappedType()).isSameAs(STR_TYPE);
+  }
 
   private static FileInput inferTypes(String lines) {
     return inferTypes(lines, PROJECT_LEVEL_TYPE_TABLE);