feat(verify): report a deleted subject as removed, not resolved

Found by dogfooding on nuwayze main: `pipe verify` against the ratchet
baseline printed

  resolved  1 no longer reported - these fixes are confirmed
    + service_browse_bloc.dart:20  LoadServicesByArtist  [dead-handler]

but nothing was fixed. nuwayze commit ccca9bd1e ("delete dead firestore
query code") deleted the event and its handler. Under pipe's default
wire-up policy, deleting an unreachable handler is the exception that
needs approval, so calling it a confirmed fix overstated what happened.

verify now separates the two. A gone finding is REMOVED when its
subject no longer exists:
- its file is not among the project's files;
- for rules labelled by a declaration (the event/state/union/provider or
  owner class), that name is no longer declared anywhere;
- for dead-handler, the on<Event> registration itself is gone.
Everything else stays RESOLVED. Member-labelled rules (a method or
build) are classed by file only, never guessed. Removed entries still
count as gone for --expect-resolved; they are only named honestly, in
text ("removed   N gone because the code was deleted - not wired up",
a REMOVED section) and JSON (removed, removedEntries).

On nuwayze main the entry now reads REMOVED. Tests: a unit test over
hand-built entries (a wired handler stays resolved, a deleted handler
and a deleted file are removed, a member label is not guessed), and an
end-to-end test that deletes a fixture's dead handler and runs
verifyAnalysis. 216 tests pass.

docs/usage.md

@@ -119,6 +119,14 @@ was not scanned. `verify` only calls a finding resolved when it looked for it:
 - a scan with a file that failed to resolve, or truncated by `--limit`, is
   refused.
 
+A finding can also go away because its subject was deleted instead of fixed.
+Those are listed as **REMOVED** ("gone because the code was deleted - not wired
+up"), not as confirmed fixes: the finding's file is gone, its event, state,
+provider or owner class is no longer declared, or, for a dead handler, the
+`on<Event>` registration itself was deleted. Removed entries still count as gone
+for `--expect-resolved`. Findings labelled by a member (a method or `build`) are
+classed by file only.
+
 ## Fix order
 
 `pipe suggest` collapses findings to root causes (one action per union,

lib/src/analysis.dart

@@ -117,6 +117,39 @@ UnresolvedReferences findUnresolvedReferences(List<FileOutcome> outcomes) {
   );
 }
 
+/// Every type, enum constant and top-level name declared in the resolved units.
+/// `verify` uses it to tell a finding that went away because its subject was
+/// deleted from one that went away because the code was fixed.
+Set<String> declaredNamesOf(List<FileOutcome> outcomes) {
+  final names = <String>{};
+  for (final outcome in outcomes) {
+    final unit = outcome.unit;
+    if (unit == null) continue;
+    for (final declaration in unit.unit.declarations) {
+      switch (declaration) {
+        case ClassDeclaration():
+          names.add(declaration.namePart.typeName.lexeme);
+        case MixinDeclaration():
+          names.add(declaration.name.lexeme);
+        case EnumDeclaration():
+          names.add(declaration.namePart.typeName.lexeme);
+          for (final constant in declaration.body.constants) {
+            names.add(constant.name.lexeme);
+          }
+        case FunctionDeclaration():
+          names.add(declaration.name.lexeme);
+        case TopLevelVariableDeclaration():
+          for (final variable in declaration.variables.variables) {
+            names.add(variable.name.lexeme);
+          }
+        default:
+          break;
+      }
+    }
+  }
+  return names;
+}
+
 class _Names extends RecursiveAstVisitor<void> {
   final Set<String> names = {};
 

lib/src/verify.dart

@@ -1,5 +1,6 @@
 import 'package:path/path.dart' as p;
 
+import 'analysis.dart';
 import 'pipeline.dart';
 import 'rules.dart';
 
@@ -16,6 +17,7 @@ class VerificationReport {
     required this.newFindings,
     this.outOfScope = 0,
     this.notScanned = const [],
+    this.removed = const [],
   });
 
   /// Accepted findings of the rules that ran, i.e. the ones this report judges.
@@ -25,9 +27,16 @@ class VerificationReport {
   /// neither resolved nor still present: nothing looked for them.
   final int outOfScope;
 
-  /// Accepted findings that are no longer reported.
+  /// Accepted findings that are no longer reported while their subject still
+  /// exists: the code was changed, and the finding went away.
   final List<BaselineEntry> resolved;
 
+  /// Accepted findings that are gone because their subject was deleted - the
+  /// file, the event or state class, the provider, or the handler. The finding
+  /// no longer applies, but under the default wire-up policy a deletion is not
+  /// the fix it asked for, so it is reported apart from [resolved].
+  final List<BaselineEntry> removed;
+
   /// Accepted findings that are still reported.
   final List<BaselineEntry> stillPresent;
 
@@ -43,16 +52,20 @@ class VerificationReport {
   /// True only when every accepted finding was looked for and is gone: an
   /// accepted finding in an unscanned file is not a confirmed fix.
   bool get allResolved => stillPresent.isEmpty && notScanned.isEmpty;
+  // Removed entries are gone too, so they do not hold `--expect-resolved` back;
+  // they are only named differently.
 
   Map<String, Object?> toJson() => {
     'baselineTotal': baselineTotal,
     'outOfScope': outOfScope,
     'resolved': resolved.length,
+    'removed': removed.length,
     'stillPresent': stillPresent.length,
     'notScanned': notScanned.length,
     'new': newFindings.length,
     'allResolved': allResolved,
     'resolvedEntries': [for (final entry in resolved) entry.toJson()],
+    'removedEntries': [for (final entry in removed) entry.toJson()],
     'stillPresentEntries': [for (final entry in stillPresent) entry.toJson()],
     'notScannedEntries': [for (final entry in notScanned) entry.toJson()],
     'newFindings': [for (final finding in newFindings) finding.toJson()],
@@ -71,6 +84,12 @@ class VerificationReport {
         'resolved  ${resolved.length} no longer reported'
         '${resolved.isEmpty ? '' : ' — these fixes are confirmed'}',
       )
+      ..write(
+        removed.isEmpty
+            ? ''
+            : 'removed   ${removed.length} gone because the code was deleted - '
+                  'not wired up\n',
+      )
       ..writeln('still     ${stillPresent.length} still reported')
       ..write(
         notScanned.isEmpty
@@ -88,6 +107,15 @@ class VerificationReport {
         );
       }
     }
+    if (removed.isNotEmpty) {
+      buffer.writeln('REMOVED');
+      for (final entry in removed.take(top)) {
+        buffer.writeln(
+          '  x ${entry.location}  ${entry.label}'
+          '  [${entry.rule}]',
+        );
+      }
+    }
     if (stillPresent.isNotEmpty) {
       buffer.writeln('STILL PRESENT');
       for (final entry in stillPresent.take(top)) {
@@ -134,6 +162,21 @@ String? baselineEntryFile(BaselineEntry entry) {
   return parts.length > 1 && parts[1].isNotEmpty ? parts[1] : null;
 }
 
+/// Rules whose baseline label names a declaration - an event or state class, a
+/// provider, or the owning class - so its absence from the code means the
+/// subject was deleted. The other rules label a member (a method or `build`),
+/// which the declaration check cannot see, so they are never classed as
+/// removed on that basis.
+const Set<String> _declarationLabelledRules = {
+  ruleEmittedNotRendered,
+  ruleRenderedNotEmitted,
+  ruleEventWithoutHandler,
+  ruleDeadHandler,
+  ruleRiverpodAsyncGap,
+  ruleNotifierInert,
+  ruleNotifierFieldUnread,
+};
+
 /// Compare a fresh analysis against the accepted baseline.
 ///
 /// Self-contained: it derives new findings by comparing fingerprints, so it does
@@ -146,13 +189,43 @@ String? baselineEntryFile(BaselineEntry entry) {
 /// An accepted finding in a file that was not analysed - one of
 /// [unscannedFiles], or outside every one of [scannedDirectories] - is reported
 /// as not scanned. Its absence is not a fix.
+///
+/// A gone finding whose subject no longer exists - its file is not among
+/// [existingFiles], its declaration is not among [declaredNames], or, for a
+/// dead handler, its event is not among [handledEvents] - is reported as
+/// removed rather than resolved. Each check runs only when its set is given.
 VerificationReport verifyAgainstBaseline({
   required FindingReport report,
   required List<BaselineEntry> baseline,
   Set<String>? rules,
   Set<String> unscannedFiles = const {},
   List<String>? scannedDirectories,
+  Set<String>? existingFiles,
+  Set<String>? declaredNames,
+  Set<String>? handledEvents,
 }) {
+  bool subjectRemoved(BaselineEntry entry) {
+    final file = baselineEntryFile(entry);
+    if (existingFiles != null &&
+        file != null &&
+        !existingFiles.contains(file)) {
+      return true;
+    }
+    final rule = baselineEntryRule(entry);
+    // A grouped label reads "Union [group]"; the declaration is the union.
+    final bracket = entry.label.indexOf(' [');
+    final subject = bracket < 0
+        ? entry.label
+        : entry.label.substring(0, bracket);
+    if (rule == ruleDeadHandler && handledEvents != null) {
+      return !handledEvents.contains(subject);
+    }
+    if (declaredNames != null && _declarationLabelledRules.contains(rule)) {
+      return !declaredNames.contains(subject);
+    }
+    return false;
+  }
+
   final directories = scannedDirectories;
   bool scanned(BaselineEntry entry) {
     final file = baselineEntryFile(entry);
@@ -182,12 +255,15 @@ VerificationReport verifyAgainstBaseline({
   final accepted = {for (final entry in baseline) entry.fingerprint};
   final notScanned = <BaselineEntry>[];
   final resolved = <BaselineEntry>[];
+  final removed = <BaselineEntry>[];
   final stillPresent = <BaselineEntry>[];
   for (final entry in inScope) {
     if (present.contains(entry.fingerprint)) {
       stillPresent.add(entry);
     } else if (!scanned(entry)) {
       notScanned.add(entry);
+    } else if (subjectRemoved(entry)) {
+      removed.add(entry);
     } else {
       resolved.add(entry);
     }
@@ -196,6 +272,7 @@ VerificationReport verifyAgainstBaseline({
     baselineTotal: inScope.length,
     outOfScope: baseline.length - inScope.length,
     resolved: resolved,
+    removed: removed,
     stillPresent: stillPresent,
     notScanned: notScanned,
     newFindings: [
@@ -230,5 +307,12 @@ VerificationReport verifyAnalysis({
     rules: rules,
     unscannedFiles: unscanned,
     scannedDirectories: project.directories,
+    existingFiles: {
+      for (final path in project.dartFiles) project.relative(path),
+    },
+    declaredNames: declaredNamesOf(analysis.run.outcomes),
+    handledEvents: {
+      for (final handler in analysis.flow.handlers) handler.event,
+    },
   );
 }

test/verify_removed_test.dart

@@ -0,0 +1,69 @@
+import 'dart:convert';
+import 'dart:io';
+
+import 'package:pipe/pipe.dart';
+import 'package:test/test.dart';
+
+/// A copy of the fixture, so deleting code there cannot touch the real one.
+String _fixtureCopy() {
+  final from = Directory('test/fixtures/stuck_loading');
+  final to = Directory.systemTemp.createTempSync('pipe-verify-removed');
+  for (final entity in from.listSync(recursive: true)) {
+    final relative = entity.path.substring(from.path.length + 1);
+    final target = '${to.path}/$relative';
+    if (entity is Directory) {
+      Directory(target).createSync(recursive: true);
+    } else if (entity is File) {
+      File(target)
+        ..createSync(recursive: true)
+        ..writeAsBytesSync(entity.readAsBytesSync());
+    }
+  }
+  return to.path;
+}
+
+void main() {
+  test('verify reports a deleted dead handler as removed', () async {
+    final root = _fixtureCopy();
+    final before = await analyzeProject(
+      await loadProject(root),
+      concurrency: 1,
+    );
+    final baseline = decodeBaselineEntries(
+      encodeBaseline(root, before.report.findings),
+    );
+    await before.dispose();
+    expect(
+      baseline.where(
+        (e) => e.rule == ruleDeadHandler && e.label == 'NeverDispatched',
+      ),
+      hasLength(1),
+    );
+
+    // Delete the dead handler instead of wiring it up.
+    final gaps = File('$root/lib/gaps.dart');
+    gaps.writeAsStringSync(
+      gaps.readAsStringSync().replaceFirst(
+        'on<NeverDispatched>((event, emit) => emit(const GapIdle()));',
+        '',
+      ),
+    );
+
+    final after = await analyzeProject(await loadProject(root), concurrency: 1);
+    try {
+      final verification = verifyAnalysis(analysis: after, baseline: baseline);
+      final json = jsonDecode(jsonEncode(verification.toJson())) as Map;
+      expect(
+        verification.removed.map((e) => e.label),
+        contains('NeverDispatched'),
+      );
+      expect(
+        verification.resolved.map((e) => e.label),
+        isNot(contains('NeverDispatched')),
+      );
+      expect(json['removed'], greaterThanOrEqualTo(1));
+    } finally {
+      await after.dispose();
+    }
+  });
+}

test/verify_test.dart

@@ -219,4 +219,59 @@ void main() {
     expect(verification.toJson(), containsPair('notScanned', 2));
     expect(verification.describe(), contains('NOT SCANNED'));
   });
+
+  test('a finding whose subject was deleted is removed, not resolved', () {
+    // nuwayze deleted a dead handler's event ("delete dead firestore query
+    // code") and verify printed it under "these fixes are confirmed". Under the
+    // default wire-up policy a deletion is not the fix the finding asked for.
+    Finding dead(String event, String file) => _finding(
+      rule: 'dead-handler',
+      file: file,
+      line: 5,
+      data: {'union': 'E', 'owner': 'B', 'event': event},
+    );
+    final wired = dead('Wired', 'lib/bloc.dart');
+    final deletedHandler = dead('HandlerGone', 'lib/bloc.dart');
+    final deletedFile = _finding(
+      rule: 'loading-flag-not-reset',
+      file: 'lib/gone.dart',
+      line: 3,
+      data: const {'owner': 'C', 'member': 'load'},
+    );
+    final memberFixed = _finding(
+      rule: 'loading-flag-not-reset',
+      file: 'lib/bloc.dart',
+      line: 9,
+      data: const {'owner': 'C', 'member': 'refresh'},
+    );
+    final baseline = decodeBaselineEntries(
+      encodeBaseline('/root', [
+        wired,
+        deletedHandler,
+        deletedFile,
+        memberFixed,
+      ]),
+    );
+
+    final verification = verifyAgainstBaseline(
+      report: FindingReport(
+        root: '/root',
+        findings: const [],
+        suppressed: const [],
+      ),
+      baseline: baseline,
+      existingFiles: const {'lib/bloc.dart'},
+      declaredNames: const {'Wired', 'HandlerGone', 'B', 'C'},
+      handledEvents: const {'Wired'},
+    );
+
+    // Wired still has its handler and is simply no longer reported: a fix.
+    // refresh is a member label, which the declaration check cannot judge, so
+    // it stays resolved rather than being guessed either way.
+    expect(verification.resolved.map((e) => e.label), {'Wired', 'refresh'});
+    expect(verification.removed.map((e) => e.label), {'HandlerGone', 'load'});
+    expect(verification.allResolved, isTrue, reason: 'removed is still gone');
+    expect(verification.describe(), contains('REMOVED'));
+    expect(verification.toJson()['removed'], 2);
+  });
 }