Dart Run Static Analysis

Analyzing and Fixing Dart Code

Contents

• Analysis Configuration
• Diagnostic Suppression
• Workflow: Executing Static Analysis
• Workflow: Applying Automated Fixes
• Examples

Analysis Configuration

Configure the Dart analyzer using the analysis_options.yaml file located at the package root.

• Base Configuration: Always include a standard rule set (e.g., package:lints/recommended.yaml or package:flutter_lints/flutter.yaml) using the include: directive.
• Strict Type Checks: Enable strict type checks under the analyzer: language: node to prevent implicit downcasts and dynamic inferences. Set strict-casts: true, strict-inference: true, and strict-raw-types: true.
• Linter Rules: Explicitly enable or disable specific rules under the linter: rules: node. Use a key-value map (rule_name: true/false) when overriding included rules, or a list (- rule_name) when defining a fresh set. Do not mix list and map syntax in the same rules block.
• Formatter Configuration: Configure dart format behavior under the formatter: node. Set page_width (default 80) and trailing_commas (automate or preserve).
• Analyzer Plugins: Enable custom diagnostics by adding plugins under the analyzer: plugins: node. Ensure the plugin package is added as a dev_dependency in pubspec.yaml.

Diagnostic Suppression

When a diagnostic (lint or warning) yields a false positive or applies to generated code, suppress it explicitly.

• File-level Exclusion: Use the analyzer: exclude: node in analysis_options.yaml to exclude entire files or directories (e.g., **/*.g.dart) using glob patterns.
• File-level Suppression: Add // ignore_for_file: <diagnostic_code> at the top of a Dart file to suppress specific diagnostics for the entire file. Use // ignore_for_file: type=lint to suppress all linter rules.
• Line-level Suppression: Add // ignore: <diagnostic_code> on the line directly above the offending code, or appended to the end of the offending line.
• Pubspec Suppression: Add # ignore: <diagnostic_code> above the offending line in pubspec.yaml files (e.g., # ignore: sort_pub_dependencies).
• Plugin Diagnostics: Prefix the diagnostic code with the plugin name when suppressing plugin-specific issues (e.g., // ignore: some_plugin/some_code).

Workflow: Executing Static Analysis

Use this workflow to identify type-related bugs, style violations, and potential runtime errors.

Task Progress:

• 1. Verify analysis_options.yaml exists at the project root.
• 2. Run the analyzer using the analyze_files MCP tool (if available) or the CLI command dart analyze <target_directory>.
• 3. Review the diagnostic output.
• 4. If info-level issues must be treated as failures, append the --fatal-infos flag.
• 5. Resolve reported errors manually or proceed to the Automated Fixes workflow.

Workflow: Applying Automated Fixes

Use this workflow to resolve outdated API usages, apply quick fixes, and migrate code (e.g., Dart 3 migrations).

Task Progress:

• 1. Execute a dry run to preview proposed changes using the dart_fix MCP tool or CLI command dart fix --dry-run.
• 2. Review the proposed fixes to ensure they align with the intended architecture.
• 3. If additional fixes are required, verify that the corresponding linter rules are enabled in analysis_options.yaml.
• 4. Apply the fixes using the dart_fix MCP tool or CLI command dart fix --apply.
• 5. Format the modified code using the dart_format MCP tool or CLI command dart format ..
• 6. Run the static analysis workflow to verify all diagnostics are resolved.

Examples

Comprehensive analysis_options.yaml

include: package:flutter_lints/recommended.yaml
analyzer:  exclude:    - "**/*.g.dart"    - "lib/generated/**"  language:    strict-casts: true    strict-inference: true    strict-raw-types: true  errors:    todo: ignore    invalid_assignment: warning    missing_return: error
linter:  rules:    avoid_shadowing_type_parameters: false    await_only_futures: true    use_super_parameters: true
formatter:  page_width: 100  trailing_commas: preserve

Inline Diagnostic Suppression

// Suppress for the entire file// ignore_for_file: unused_local_variable, dead_code
void processData() {  // Suppress for a specific line  // ignore: invalid_assignment  int x = '';    const y = 10; // ignore: constant_identifier_names}