dart-fix-runtime-errors

Name: dart-fix-runtime-errors
Author: flutter

792installs159forks

How to install dart-fix-runtime-errors?

flutter/agent-plugins/dart-fix-runtime-errors

$npx -y skills add flutter/agent-plugins --skill dart-fix-runtime-errors

Installs into the current project.

Summary

Uses get_runtime_errors and lsp to fetch an active stack trace, locate the failing line, apply a fix, and verify resolution via hot_reload.

Files · 1

View on GitHub

SKILL.md

1	# Resolving Dart Static Analysis Errors
2
3	## Contents
4	- [Core Concepts & Guidelines](#core-concepts--guidelines)
5	- [Type System & Soundness](#type-system--soundness)
6	- [Null Safety](#null-safety)
7	- [Error Handling](#error-handling)
8	- [Workflows](#workflows)
9	- [Workflow: Static Analysis Resolution](#workflow-static-analysis-resolution)
10	- [Examples](#examples)
11
12	## Core Concepts & Guidelines
13
14	### Type System & Soundness
15	Enforce Dart's sound type system to prevent runtime invalid states.
16
17	* Method Overrides: Maintain sound return types (covariant) and parameter types (contravariant). Never tighten a parameter type in a subclass unless explicitly marked with the `covariant` keyword.
18	* Generics & Collections: Add explicit type annotations to generic classes (e.g., `List<T>`, `Map<K, V>`). Never assign a `List<dynamic>` to a typed list (e.g., `List<Cat>`).
19	* Downcasting: Avoid implicit downcasts from `dynamic`. Use explicit casts (e.g., `as List<Cat>`) when necessary, but ensure the underlying runtime type matches to prevent `TypeError` exceptions.
20	* Strict Casts: Enable `strict-casts: true` in `analysis_options.yaml` under `analyzer: language:` to force explicit casting and catch implicit downcast errors at compile time.
21
22	### Null Safety
23	Eliminate static errors related to null safety by correctly managing variable initialization and nullability.
24
25	* Modifiers: Apply `?` for nullable types, `!` for null assertions, and `required` for named parameters that cannot be null.
26	* Late Initialization: Use the `late` keyword for non-nullable variables guaranteed to be initialized before use. Apply this specifically to top-level or instance variables where Dart's control flow analysis cannot definitively prove initialization.
27	* Wildcards: Use the `_` wildcard variable (Dart 3.7+) for non-binding local variables or parameters to avoid unused variable warnings.
28
29	### Error Handling
30	Distinguish between recoverable exceptions and unrecoverable errors.
31
32	* Catching: Catch `Exception` subtypes for recoverable failures.
33	* Errors: Never explicitly catch `Error` or its subtypes (e.g., `TypeError`, `ArgumentError`). Errors indicate programming bugs that must be fixed, not caught. Enforce this by enabling the `avoid_catching_errors` linter rule.
34	* Rethrowing: Use `rethrow` inside a `catch` block to propagate an exception while preserving its original stack trace.
35
36	## Workflows
37
38	### Workflow: Static Analysis Resolution
39
40	Use this sequential workflow to identify, fix, and verify static analysis errors in a Dart project. Copy the checklist to track your progress.
41
42	Task Progress:
43	- [ ] 1. Run static analyzer.
44	- [ ] 2. Apply automated fixes.
45	- [ ] 3. Resolve remaining errors manually.
46	- [ ] 4. Verify fixes (Feedback Loop).
47
48	1. Run static analyzer
49	Execute the Dart analyzer to identify all static errors in the target directory or file.
50	```bash
51	dart analyze . --fatal-infos
52	```
53
54	2. Apply automated fixes
55	Use the `dart fix` tool to automatically resolve standard linting and analysis issues.
56	```bash
57	# Preview changes
58	dart fix --dry-run
59	# Apply changes
60	dart fix --apply
61	```
62
63	3. Resolve remaining errors manually
64	Review the remaining analyzer output and apply conditional logic based on the error type:
65
66	* If the error is a Null Safety issue (e.g., "Property cannot be accessed on a nullable receiver"):
67	* Verify if the variable can logically be null.
68	* If yes, use optional chaining (`?.`) or provide a fallback (`??`).
69	* If no, and initialization is guaranteed elsewhere, mark the declaration with `late`.
70	* If the error is a Type Mismatch (e.g., "The argument type 'List<dynamic>' can't be assigned..."):
71	* Trace the variable's initialization.
72	* Add explicit generic type annotations to the instantiation (e.g., `<int>[]` instead of `[]`).
73	* If the error is an Invalid Override (e.g., "The parameter type doesn't match the overridden method"):
74	* Widen the parameter type to match the superclass, OR
75	* Add the `covariant` keyword to the parameter if tightening the type is intentionally required by the domain logic.
76
77	4. Verify fixes (Feedback Loop)
78	Run the validator. Review errors. Fix.
79	```bash
80	dart analyze .
81	dart test
82	```
83	* If `dart analyze` reports errors: Return to Step 3.
84	* If `dart test` fails with a `TypeError`: You have introduced an invalid explicit cast (`as T`) or accessed an uninitialized `late` variable. Locate the runtime failure and correct the type hierarchy or initialization order.
85
86	## Examples
87
88	### Example: Fixing Dynamic List Assignments
89	Input (Fails Static Analysis):
90	```dart
91	void printInts(List<int> a) => pri

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dart-fix-runtime-errors

792installs159forks

View on GitHub

How to install dart-fix-runtime-errors?

flutter/agent-plugins/dart-fix-runtime-errors

$npx -y skills add flutter/agent-plugins --skill dart-fix-runtime-errors

Installs into the current project.

Summary

Uses get_runtime_errors and lsp to fetch an active stack trace, locate the failing line, apply a fix, and verify resolution via hot_reload.

Files · 1

View on GitHub

SKILL.md

1	# Resolving Dart Static Analysis Errors
2
3	## Contents
4	- [Core Concepts & Guidelines](#core-concepts--guidelines)
5	- [Type System & Soundness](#type-system--soundness)
6	- [Null Safety](#null-safety)
7	- [Error Handling](#error-handling)
8	- [Workflows](#workflows)
9	- [Workflow: Static Analysis Resolution](#workflow-static-analysis-resolution)
10	- [Examples](#examples)
11
12	## Core Concepts & Guidelines
13
14	### Type System & Soundness
15	Enforce Dart's sound type system to prevent runtime invalid states.
16
17	* Method Overrides: Maintain sound return types (covariant) and parameter types (contravariant). Never tighten a parameter type in a subclass unless explicitly marked with the `covariant` keyword.
18	* Generics & Collections: Add explicit type annotations to generic classes (e.g., `List<T>`, `Map<K, V>`). Never assign a `List<dynamic>` to a typed list (e.g., `List<Cat>`).
19	* Downcasting: Avoid implicit downcasts from `dynamic`. Use explicit casts (e.g., `as List<Cat>`) when necessary, but ensure the underlying runtime type matches to prevent `TypeError` exceptions.
20	* Strict Casts: Enable `strict-casts: true` in `analysis_options.yaml` under `analyzer: language:` to force explicit casting and catch implicit downcast errors at compile time.
21
22	### Null Safety
23	Eliminate static errors related to null safety by correctly managing variable initialization and nullability.
24
25	* Modifiers: Apply `?` for nullable types, `!` for null assertions, and `required` for named parameters that cannot be null.
26	* Late Initialization: Use the `late` keyword for non-nullable variables guaranteed to be initialized before use. Apply this specifically to top-level or instance variables where Dart's control flow analysis cannot definitively prove initialization.
27	* Wildcards: Use the `_` wildcard variable (Dart 3.7+) for non-binding local variables or parameters to avoid unused variable warnings.
28
29	### Error Handling
30	Distinguish between recoverable exceptions and unrecoverable errors.
31
32	* Catching: Catch `Exception` subtypes for recoverable failures.
33	* Errors: Never explicitly catch `Error` or its subtypes (e.g., `TypeError`, `ArgumentError`). Errors indicate programming bugs that must be fixed, not caught. Enforce this by enabling the `avoid_catching_errors` linter rule.
34	* Rethrowing: Use `rethrow` inside a `catch` block to propagate an exception while preserving its original stack trace.
35
36	## Workflows
37
38	### Workflow: Static Analysis Resolution
39
40	Use this sequential workflow to identify, fix, and verify static analysis errors in a Dart project. Copy the checklist to track your progress.
41
42	Task Progress:
43	- [ ] 1. Run static analyzer.
44	- [ ] 2. Apply automated fixes.
45	- [ ] 3. Resolve remaining errors manually.
46	- [ ] 4. Verify fixes (Feedback Loop).
47
48	1. Run static analyzer
49	Execute the Dart analyzer to identify all static errors in the target directory or file.
50	```bash
51	dart analyze . --fatal-infos
52	```
53
54	2. Apply automated fixes
55	Use the `dart fix` tool to automatically resolve standard linting and analysis issues.
56	```bash
57	# Preview changes
58	dart fix --dry-run
59	# Apply changes
60	dart fix --apply
61	```
62
63	3. Resolve remaining errors manually
64	Review the remaining analyzer output and apply conditional logic based on the error type:
65
66	* If the error is a Null Safety issue (e.g., "Property cannot be accessed on a nullable receiver"):
67	* Verify if the variable can logically be null.
68	* If yes, use optional chaining (`?.`) or provide a fallback (`??`).
69	* If no, and initialization is guaranteed elsewhere, mark the declaration with `late`.
70	* If the error is a Type Mismatch (e.g., "The argument type 'List<dynamic>' can't be assigned..."):
71	* Trace the variable's initialization.
72	* Add explicit generic type annotations to the instantiation (e.g., `<int>[]` instead of `[]`).
73	* If the error is an Invalid Override (e.g., "The parameter type doesn't match the overridden method"):
74	* Widen the parameter type to match the superclass, OR
75	* Add the `covariant` keyword to the parameter if tightening the type is intentionally required by the domain logic.
76
77	4. Verify fixes (Feedback Loop)
78	Run the validator. Review errors. Fix.
79	```bash
80	dart analyze .
81	dart test
82	```
83	* If `dart analyze` reports errors: Return to Step 3.
84	* If `dart test` fails with a `TypeError`: You have introduced an invalid explicit cast (`as T`) or accessed an uninitialized `late` variable. Locate the runtime failure and correct the type hierarchy or initialization order.
85
86	## Examples
87
88	### Example: Fixing Dynamic List Assignments
89	Input (Fails Static Analysis):
90	```dart
91	void printInts(List<int> a) => pri

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6 picks

Type