dependency_lens

Flutter DevTools extension and CLI for visualizing local module dependencies and detecting cyclic dependencies in Dart and Flutter modular workspaces.

dependency_lens is a DevTools extension package, not a native Android or iOS Flutter plugin. It scans local Dart and Flutter packages, shows a dependency matrix and graph, detects dependency cycles, and reports unused declared local dependencies.

CLI

dart run dependency_lens:dependency_lens scan --root .

Use --format text, --format json, or --format dot. The command exits with code 1 when dependency cycles are found.

For CI, use the dedicated check command:

dart run dependency_lens:dependency_lens check --root .

It exits with code 0 when no cycles are found and 1 when any cycle is detected, including multi-package cycles such as a -> b -> c -> a. Warnings, such as missing direct dependencies, do not fail the check.

To also fail CI for unused local dependencies, pass:

dart run dependency_lens:dependency_lens check --root . --fail-on-unused-dependencies

Configuration

Both the CLI and DevTools UI read dependency_lens.yaml from the workspace root when it exists. CLI flags override YAML values.

include_root_package: true
local_package_roots:
  - modules
  - plugins
  - packages
source_roots:
  - lib
  - bin
  - test
  - tool
dependency_sections:
  - dependencies
  - dev_dependencies
  - dependency_overrides
excluded_package_names: []
excluded_package_paths: []
ignored_directory_names:
  - .dart_tool
  - .git
  - .idea
  - .symlinks
  - build
  - Pods
ignored_file_suffixes:
  - .g.dart
  - .freezed.dart
  - .config.dart
  - .module.dart

Both scan and check accept configuration flags backed by DependencyLensConfig:

dart run dependency_lens:dependency_lens scan --root . \
  --package-root modules \
  --package-root packages \
  --source-root lib \
  --dependency-section dependencies \
  --exclude-package legacy_module \
  --exclude-path plugins/example_plugin/example \
  --ignore-dir generated \
  --ignore-suffix .gen.dart \
  --no-root-package

DevTools

Add dependency_lens as a dev_dependency, run flutter pub get, then enable the extension in Flutter DevTools.

dev_dependencies:
  dependency_lens: ^0.1.2

The DevTools UI includes:

• Matrix: package-by-package dependency grid with D+I, D, I, and UNUSED cell markers
• Graph: interactive dependency graph with direction arrows
• Cycles: exact cycle paths and evidence
• Unused: declared local path dependencies that are not imported or exported
• Settings: editable dependency_lens.yaml configuration

Programmatic usage can pass the same configuration object:

runApp(
  const DependencyLensApp(
    config: DependencyLensConfig(
      localPackageRoots: <String>['modules', 'packages'],
      dependencySections: <String>['dependencies'],
      excludedPackagePaths: <String>{'plugins/example_plugin/example'},
    ),
  ),
);