Propagate check flags in patch mode

check_api/src/main/java/com/google/errorprone/ErrorProneAnalyzer.java

@@ -80,13 +80,12 @@ public static ErrorProneAnalyzer createAnalyzer(
                 Suppliers.memoize(
                     () -> {
                       ScannerSupplier toUse =
-                          ErrorPronePlugins.loadPlugins(scannerSupplier, context);
+                          ErrorPronePlugins.loadPlugins(scannerSupplier, context)
+                              .applyOverrides(epOptions);
                       ImmutableSet<String> namedCheckers =
                           epOptions.patchingOptions().namedCheckers();
                       if (!namedCheckers.isEmpty()) {
                         toUse = toUse.filter(bci -> namedCheckers.contains(bci.canonicalName()));
-                      } else {
-                        toUse = toUse.applyOverrides(epOptions);
                       }
                       return ErrorProneScannerTransformer.create(toUse.get());
                     }));

core/src/test/java/com/google/errorprone/ErrorProneJavaCompilerTest.java

@@ -34,6 +34,7 @@
 import com.google.errorprone.bugpatterns.BadShiftAmount;
 import com.google.errorprone.bugpatterns.BugChecker;
 import com.google.errorprone.bugpatterns.BugChecker.ClassTreeMatcher;
+import com.google.errorprone.bugpatterns.BugChecker.VariableTreeMatcher;
 import com.google.errorprone.bugpatterns.ChainingConstructorIgnoresParameter;
 import com.google.errorprone.bugpatterns.Finally;
 import com.google.errorprone.fixes.SuggestedFix;
@@ -42,21 +43,27 @@
 import com.google.errorprone.util.ASTHelpers;
 import com.sun.source.tree.ClassTree;
 import com.sun.source.tree.MethodTree;
+import com.sun.source.tree.VariableTree;
 import com.sun.tools.javac.file.JavacFileManager;
+import com.sun.tools.javac.util.Constants;
 import java.io.ByteArrayOutputStream;
 import java.io.IOException;
 import java.io.InputStream;
 import java.io.OutputStream;
 import java.io.OutputStreamWriter;
 import java.io.PrintWriter;
+import java.nio.file.Files;
+import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.Collections;
 import java.util.List;
 import java.util.Locale;
+import javax.inject.Inject;
 import javax.lang.model.SourceVersion;
 import javax.tools.DiagnosticListener;
 import javax.tools.JavaCompiler;
 import javax.tools.JavaFileObject;
+import javax.tools.SimpleJavaFileObject;
 import org.junit.Rule;
 import org.junit.Test;
 import org.junit.rules.TemporaryFolder;
@@ -410,6 +417,59 @@ public void withExcludedPaths() {
     assertThat(result.succeeded).isFalse();
   }
 
+  @BugPattern(summary = "Test bug pattern to test custom patch functionality", severity = ERROR)
+  public static final class AssignmentUpdater extends BugChecker implements VariableTreeMatcher {
+    private final String newValue;
+
+    @Inject
+    AssignmentUpdater(ErrorProneFlags flags) {
+      newValue = flags.get("AssignmentUpdater:NewValue").orElse("flag-not-set");
+    }
+
+    @Override
+    public Description matchVariable(VariableTree tree, VisitorState state) {
+      return describeMatch(
+          tree, SuggestedFix.replace(tree.getInitializer(), Constants.format(newValue)));
+    }
+  }
+
+  @Test
+  public void patchWithBugPatternCustomization() throws IOException {
+    // Patching modifies files on disk, so we must create an actual file that matches the
+    // `SimpleJavaFileObject` defined below.
+    Path location = tempDir.getRoot().toPath().resolve("StringConstantWrapper.java");
+    String source =
+        """
+        class StringConstantWrapper {
+          String s = "old-value";
+        }
+        """;
+    Files.writeString(location, source);
+
+    CompilationResult result =
+        doCompile(
+            Collections.singleton(
+                new SimpleJavaFileObject(location.toUri(), SimpleJavaFileObject.Kind.SOURCE) {
+                  @Override
+                  public CharSequence getCharContent(boolean ignoreEncodingErrors) {
+                    return source;
+                  }
+                }),
+            Arrays.asList(
+                "-XepPatchChecks:AssignmentUpdater",
+                "-XepPatchLocation:IN_PLACE",
+                "-XepOpt:AssignmentUpdater:NewValue=new-value"),
+            Collections.singletonList(AssignmentUpdater.class));
+    assertThat(result.succeeded).isTrue();
+    assertThat(Files.readString(location))
+        .isEqualTo(
+            """
+            class StringConstantWrapper {
+              String s = "new-value";
+            }
+            """);
+  }
+
   private static class CompilationResult {
     public final boolean succeeded;
     public final String output;
@@ -427,6 +487,14 @@ private CompilationResult doCompile(
       List<String> fileNames,
       List<String> extraArgs,
       List<Class<? extends BugChecker>> customCheckers) {
+    return doCompile(
+        forResources(getClass(), fileNames.toArray(new String[0])), extraArgs, customCheckers);
+  }
+
+  private CompilationResult doCompile(
+      Iterable<? extends JavaFileObject> files,
+      List<String> extraArgs,
+      List<Class<? extends BugChecker>> customCheckers) {
     DiagnosticTestHelper diagnosticHelper = new DiagnosticTestHelper();
     ByteArrayOutputStream outputStream = new ByteArrayOutputStream();
     PrintWriter printWriter = new PrintWriter(new OutputStreamWriter(outputStream, UTF_8), true);
@@ -441,12 +509,7 @@ private CompilationResult doCompile(
             : new ErrorProneJavaCompiler(ScannerSupplier.fromBugCheckerClasses(customCheckers));
     JavaCompiler.CompilationTask task =
         errorProneJavaCompiler.getTask(
-            printWriter,
-            fileManager,
-            diagnosticHelper.collector,
-            args,
-            null,
-            forResources(getClass(), fileNames.toArray(new String[0])));
+            printWriter, fileManager, diagnosticHelper.collector, args, null, files);
 
     return new CompilationResult(
         task.call(), new String(outputStream.toByteArray(), UTF_8), diagnosticHelper);