flutter_risk_detector 0.1.0

A Flutter debugging toolkit that detects RenderFlex overflows, rebuild storms, async risks, memory leaks, jank, and lint issues at runtime and via static analysis.

0.1.0 — 2026-05-17

Added

Overflow Detection

• Detects RenderFlex overflowed errors via FlutterError.onError
• Reports best-effort widget name, parent widget, file path, line, column, overflow direction, and pixel amount
• Direction-specific fix suggestions (horizontal vs vertical)
• Skips generated .g.dart and framework stack frames to surface user code location

Rebuild Storm Detection

• RiskRebuildTracker widget wraps any subtree and monitors rebuild rate
• Reports storm when rebuild count exceeds configurable threshold (default: 20)
• Detects 7 cause categories: setState in build loop, stream flooding, ancestor propagation, Provider over-notification, AnimationController without const subtrees, object creation in build, parent setState
• Each cause maps to specific, actionable fix suggestions
• Reports throttled to once per 3 seconds to prevent log flooding
• Logs only at milestone counts (5, 10, 20, 50, 100) below the warning threshold

Jank Detection

• RiskRebuildTracker registers a SchedulerBinding.addTimingsCallback
• Logs any frame where buildDuration exceeds the configurable threshold (default: 16ms / 60fps)
• Reports build and raster duration in milliseconds
• Callback removed in dispose() — no memory leak

Async Risk Detection

• Catches setState() called after dispose via FlutterError.onError
• Catches unhandled async errors via PlatformDispatcher.onError
• Preserves and delegates to existing Flutter and platform error handlers
• Classifies 4 risk types: setStateAfterDispose, streamNotCancelled, timerNotCancelled, futureAfterDispose
• Each type produces a specific cause + fix message
• Public classify() method for custom handling

Static Lint Analysis

• LintAnalyzer.analyzeDirectory() scans all .dart files under a directory
• LintAnalyzer.analyzeFile() scans a single file
• 18 lint rules across 3 categories: code quality, memory leaks, jank/performance
• Results grouped by file, sorted by line number, with lazy-cached byFile map
• filtered(LintSeverity) to narrow results by minimum severity
• Graceful handling of permission errors and missing files via FileSystemException catch
• Skips .g.dart generated files automatically
• Default import remains safe on non-IO platforms through a no-op analyzer stub

Configuration

• RiskDetectorConfig with copyWith, ==, and hashCode
• Configurable: rebuildWarningThreshold, rebuildStormThreshold, jankThresholdMs, lintScanDirectory
• Per-widget threshold overrides on RiskRebuildTracker

Logging

• RiskLogger with throttled warning() and error() methods (2-second dedup window)
• Circular in-memory buffer capped at 200 entries with timestamps
• Stale throttle entries pruned automatically to prevent unbounded map growth
• All methods are no-ops when kDebugMode is false

Models

• OverflowResult — const constructor, ==, hashCode
• RebuildResult — isStorm snapshotted at construction, rebuildsPerSecond getter
• LintIssue — const constructor, copyWith, ==, hashCode
• LintResult — single-pass severity counts, lazy-cached byFile, filtered(), immutable issues list
• RiskResult — copyWith, ==, hashCode
• RiskLevel — 4-tier enum with icons

Testing

• 81 unit tests covering all analyzers, models, config, and logger
• Temp-file based integration tests for LintAnalyzer rules
• Edge cases: empty strings, non-existent files/directories, zero-duration windows, unmodifiable collections