add more negative test cases

Author: nahsra

framework/codemodder-base/src/test/java/io/codemodder/remediation/xss/PrintingMethodFixerTest.java

@@ -5,6 +5,7 @@
 import com.github.javaparser.StaticJavaParser;
 import com.github.javaparser.ast.CompilationUnit;
 import com.github.javaparser.printer.lexicalpreservation.LexicalPreservingPrinter;
+import io.codemodder.CodemodFileScanningResult;
 import io.codemodder.codetf.DetectorRule;
 import io.codemodder.remediation.FixCandidateSearcher;
 import io.codemodder.remediation.SearcherStrategyRemediator;
@@ -133,7 +134,14 @@ void it_fixes_obvious_response_write_methods(final String beforeCode, final Stri
     CompilationUnit cu = StaticJavaParser.parse(beforeCode);
     LexicalPreservingPrinter.setup(cu);
 
-    XSSFinding finding = new XSSFinding("should_be_fixed", 3, null);
+    var result = scanAndFix(cu, 3);
+    assertThat(result.changes()).isNotEmpty();
+    String actualCode = LexicalPreservingPrinter.print(cu);
+    assertThat(actualCode).isEqualToIgnoringWhitespace(afterCode);
+  }
+
+  private CodemodFileScanningResult scanAndFix(final CompilationUnit cu, final int line) {
+    XSSFinding finding = new XSSFinding("should_be_fixed", line, null);
     var remediator =
         new SearcherStrategyRemediator.Builder<XSSFinding>()
             .withSearcherStrategyPair(
@@ -142,18 +150,58 @@ void it_fixes_obvious_response_write_methods(final String beforeCode, final Stri
                     .build(),
                 fixer)
             .build();
-    var result =
-        remediator.remediateAll(
-            cu,
-            "path",
-            rule,
-            List.of(finding),
-            XSSFinding::key,
-            XSSFinding::line,
-            x -> Optional.empty(),
-            x -> Optional.ofNullable(x.column()));
-    assertThat(result.changes()).isNotEmpty();
-    String actualCode = LexicalPreservingPrinter.print(cu);
-    assertThat(actualCode).isEqualToIgnoringWhitespace(afterCode);
+    return remediator.remediateAll(
+        cu,
+        "path",
+        rule,
+        List.of(finding),
+        XSSFinding::key,
+        XSSFinding::line,
+        x -> Optional.empty(),
+        x -> Optional.ofNullable(x.column()));
+  }
+
+  @ParameterizedTest
+  @MethodSource("unfixableSamples")
+  void it_does_not_fix_unfixable_response_write_methods(final String beforeCode, final int line) {
+    CompilationUnit cu = StaticJavaParser.parse(beforeCode);
+    LexicalPreservingPrinter.setup(cu);
+    var result = scanAndFix(cu, line);
+    assertThat(result.changes()).isEmpty();
+  }
+
+  private static Stream<Arguments> unfixableSamples() {
+    return Stream.of(
+        // this is all string literals -- ignore
+        Arguments.of(
+            """
+                        class Samples {
+                          void should_be_fixed(String s) {
+                            getWriter().write("<div>" + "<b>" + "</div>");
+                          }
+                        }
+                        """,
+            3),
+        // this is ambiguous which value to encode
+        Arguments.of(
+            """
+                        class Samples {
+                          void should_be_fixed(String s) {
+                            getWriter().write("<div>" + a + b + "</div>");
+                          }
+                        }
+                        """,
+            3),
+        // this is the wrong line
+        Arguments.of(
+            """
+                        class Samples {
+                          void should_be_fixed(String s) {
+                            // extra line, right line is 4
+                            getWriter().write("<div>" + a + "</div>");
+                          }
+                        }
+                        """,
+            3));
   }
 }