The latest articles on DEV Community by Nguyễn Minh Đức (@beobiebom). https://dev.to/beobiebom https://media2.dev.to/dynamic/image/width=90,height=90,fit=cover,gravity=auto,format=auto/https:%2F%2Fdev-to-uploads.s3.amazonaws.com%2Fuploads%2Fuser%2Fprofile_image%2F883583%2F7cd34387-4e2b-4083-b7eb-a020af26b8b7.jpeg https://dev.to/beobiebom en Nguyễn Minh Đức Fri, 17 Apr 2026 06:48:45 +0000 https://dev.to/beobiebom/fscan-find-dead-code-in-your-flutter-project-from-the-command-line-34md https://dev.to/beobiebom/fscan-find-dead-code-in-your-flutter-project-from-the-command-line-34md <p>Your Flutter project probably has more dead code than you think.</p> <p>Dart's analyzer is great at catching type errors. It won't tell you that<br> <code>lib/features/onboarding/legacy_screen.dart</code> hasn't been imported since March,<br> or that <code>assets/images/old_logo.png</code> is still in your pubspec but never rendered.</p> <p>I built <strong>fscan</strong> to solve this. It's a CLI tool written in Go that performs<br> static dead-code analysis across your entire Flutter/Dart project.</p> <h2> What it catches </h2> <ul> <li> <strong>Unused files</strong> — walks the import graph from your entry points, flags orphans</li> <li> <strong>Unused assets</strong> — cross-references pubspec.yaml with actual usage in code</li> <li> <strong>Unused public API</strong> — classes, functions, and widgets with no external callers</li> <li> <strong>Unused routes</strong> — supports auto_route, go_router, and Navigator named routes</li> <li> <strong>Maybe-unused methods</strong> — owner-class-aware matching to minimize false positives</li> </ul> <p><strong>Framework-aware</strong><br> Flutter requires you to declare <code>build()</code>, <code>initState()</code>, <code>dispose()</code>, and<br> <code>createState()</code> — but you never call them directly. fscan skips all framework<br> lifecycle methods and <code>@override</code> annotations.</p> <p><strong>Generated file handling</strong><br> <code>.g.dart</code>, <code>.gen.dart</code>, <code>.gr.dart</code>, <code>.freezed.dart</code> files are excluded from<br> unused-file detection. But they're still read as reference sources — so your<br> <code>flutter_gen</code> typed accessors and freezed models count as "used."</p> <p><strong>Owner-class-aware method analysis</strong><br> A method named <code>load()</code> in <code>BookService</code> is tracked separately from <code>load()</code> in<br> <code>UserService</code>. No cross-class false positives from common method names.</p> <p><strong>Same-file self-reference detection</strong><br> A public method called only within the same file (e.g., called in an event handler<br> above its declaration) is correctly marked as used.</p> <h2> Install </h2> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code> brew <span class="nb">install </span>beobeodev/tap/fscan <span class="c"># or</span> npm <span class="nb">install</span> <span class="nt">-g</span> @beobeodev/fscan <span class="c"># or</span> go <span class="nb">install </span>github.com/beobeodev/fscan@latest </code></pre> </div> <h2> Run </h2> <div class="highlight js-code-highlight"> <pre class="highlight shell"><code> fscan scan /path/to/your/flutter/project </code></pre> </div> <p>GitHub: <a href="https://github.com/beobeodev/fscan" rel="noopener noreferrer">https://github.com/beobeodev/fscan</a></p> <p>Two severity levels</p> <ul> <li>Errors = high confidence, safe to delete</li> <li>Warnings = may be intentional (public API, dynamic routing) — review first</li> </ul> flutter dart go cli