NoDirectIterableAccessRule class

Warns when a List (or other non-Map indexable collection) is indexed directly with [] instead of a bounds-safe accessor.

Since: v14.4.0 | Updated: v14.4.0 | Rule version: v2

list[index] throws RangeError the instant index falls outside the list's bounds. That failure mode is easy to miss when the index comes from user input, an API response, or a computed offset rather than a literal loop counter. Map is deliberately out of scope: Map's [] already returns null on a miss instead of throwing, so it carries none of the crash risk this rule targets.

The rule does not flag access that is statically provable to be safe: a constant index into a constant list literal; an index guarded by an explicit index < list.length check (in an if's then branch, its reversed form list.length > index, or the negated index >= list.length form guarding the else branch); the list.isNotEmpty / list.isEmpty emptiness idiom guarding a literal [0] access; the same guards expressed as a ternary (list.isEmpty ? fallback : list[0]); an early-return guard clause (if (index >= list.length) return; followed by the unguarded access); a loop variable bounded by the enclosing for/collection-for/while/do-while loop's own < list.length condition; or a preceding RangeError.checkValidIndex(index, list) call, dart:core's own recommended way to validate an index explicitly.

Example of bad code:

String firstItemLabel(List<String> items) {
  return items[0]; // Throws RangeError if items is empty
}

Example of good code:

String firstItemLabel(List<String> items) {
  return items.elementAtOrNull(0) ?? '';
}
Inheritance

Properties

accuracyTarget → AccuracyTarget?
Optional accuracy target for this rule (for documentation and tooling). Does not enforce; used by reports and rule-audit scripts.
no setterinherited
applicableFileTypes → Set<FileType>?
The file types this rule applies to.
no setterinherited
canUseParsedResult → bool
Indicates whether this analysis rule can work with just the parsed information or if it requires a resolved unit.
no setterinherited
certIds → List<String>
CERT coding standard identifiers (e.g. STR02-C). Populate only where there is a clear mapping; leave empty for most rules initially.
no setterinherited
code → LintCode
The lint code for this rule.
no setterinherited
configAliases → List<String>
Alternate config keys that can be used to reference this rule.
no setterinherited
conflictingRules → List<String>
Curated opposite/competing rule names.
no setterinherited
cost → RuleCost
The estimated execution cost of this rule.
no setteroverride
cweIds → List<int>
CWE identifiers this rule helps prevent or detect. https://cwe.mitre.org/ — e.g. CWE-798 (Hardcoded Credentials).
no setterinherited
description → String
Short description suitable for display in console output and IDEs.
finalinherited
diagnosticCode → DiagnosticCode
The code to report for a violation.
no setterinherited
diagnosticCodes → List<DiagnosticCode>
The diagnostic codes associated with this analysis rule.
no setterinherited
documentationUrl → String
Returns the documentation URL for this rule.
no setterinherited
effectiveSeverity → DiagnosticSeverity?
Get the effective severity for this rule, considering overrides.
no setterinherited
exampleBad → String?
Short code example that VIOLATES this rule (shown in CLI walkthrough).
no setterinherited
exampleGood → String?
Short code example of COMPLIANT code (shown in CLI walkthrough).
no setterinherited
fixGenerators → List<SaropaFixGenerator>
Fix producer generators for this rule.
no setterinherited
hashCode → int
The hash code for this object.
no setterinherited
hyphenatedName → String
Returns the rule name in hyphenated format for display.
no setterinherited
impact → LintImpact
A missed bounds check turns into a runtime crash the moment the index is out of range, so this is a reliability/correctness issue, not merely a style nit.
no setteroverride
incompatibleRules → List<String>
A list of incompatible rule names.
no setterinherited
isDisabled → bool
Check if this rule is disabled via configuration.
no setterinherited
maximumLineCount → int
Maximum line count for this rule to run.
no setterinherited
minimumLineCount → int
Minimum line count for this rule to run.
no setterinherited
name → String
The rule name.
finalinherited
owasp → OwaspMapping?
OWASP categories this rule helps prevent.
no setterinherited
pubspecVisitor → PubspecVisitor?
A visitor that visits a Pubspec to perform analysis.
no setterinherited
relatedRules → List<String>
Curated "see also" rule names for discoverability in docs/IDE tooling.
no setterinherited
reporter ← DiagnosticReporter
Sets the DiagnosticReporter for the CompilationUnit currently being visited.
no getterinherited
requiredPatterns → Set<String>?
String patterns that must be present in the file for this rule to run.
no setteroverride
requiresAsync → bool
Whether this rule only applies to async code.
no setterinherited
requiresBlocImport → bool
Whether this rule only applies to files that import Bloc.
no setterinherited
requiresClassDeclaration → bool
Whether this rule only applies to files with class declarations.
no setterinherited
requiresFlutterImport → bool
Whether this rule only applies to files that import Flutter.
no setterinherited
requiresImports → bool
Whether this rule only applies to files with imports.
no setterinherited
requiresMainFunction → bool
Whether this rule only applies to files with a main() function.
no setterinherited
requiresProviderImport → bool
Whether this rule only applies to files that import Provider.
no setterinherited
requiresRiverpodImport → bool
Whether this rule only applies to files that import Riverpod.
no setterinherited
requiresWidgets → bool
Whether this rule only applies to Flutter widget code.
no setterinherited
ruleStatus → RuleStatus
Lifecycle status. Default RuleStatus.ready. Use RuleStatus.beta for new or heuristic-heavy rules; RuleStatus.deprecated for sunset.
no setterinherited
ruleType → RuleType?
Semantic type of this rule. Default null = unspecified (legacy). When set, used for quality gates, accuracy targets, and reporting.
no setteroverride
runtimeType → Type
A representation of the runtime type of the object.
no setterinherited
skipExampleFiles → bool
Whether to skip example files (example/**).
no setterinherited
skipFixtureFiles → bool
Whether to skip fixture files (fixture/, fixtures/).
no setterinherited
skipGeneratedCode → bool
Whether to skip generated files (*.g.dart, *.freezed.dart, *.gen.dart).
no setterinherited
skipTestFiles → bool
Whether to skip test files (*_test.dart, test/**).
no setterinherited
state → RuleState
The state of this analysis rule.
finalinherited
supersedesRules → List<String>
Rule names this rule supersedes/replaces.
no setterinherited
tags → Set<String>
Tags for filtering and discovery (e.g. in docs, IDE, or CI). Examples: 'performance', 'accessibility', 'suspicious', 'convention'.
no setteroverride
testRelevance → TestRelevance
How this rule relates to test files.
no setterinherited
usesTypeResolution → bool
Whether this rule triggers lazy cross-library type resolution in the analyzer (e.g. .staticType, .library, .allSupertypes, .enclosingElement).
no setteroverride

Methods

noSuchMethod(Invocation invocation) → dynamic
Invoked when a nonexistent method or property is accessed.
inherited
registerNodeProcessors(RuleVisitorRegistry registry, RuleContext context) → void
Registers node processors in the given registry.
inherited
reportAtNode(AstNode? node, {List<Object> arguments = const [], List<DiagnosticMessage>? contextMessages}) → Diagnostic?
Reports a diagnostic at node with message arguments and contextMessages.
inherited
reportAtOffset(int offset, int length, {List<Object> arguments = const [], List<DiagnosticMessage>? contextMessages}) → Diagnostic
Reports a diagnostic at offset, with length, with message arguments and contextMessages.
inherited
reportAtPubNode(PubspecNode node, {List<Object> arguments = const [], List<DiagnosticMessage> contextMessages = const []}) → Diagnostic
Reports a diagnostic at Pubspec node, with message arguments and contextMessages.
inherited
reportAtSourceRange(SourceRange sourceRange, {List<Object> arguments = const [], List<DiagnosticMessage>? contextMessages}) → Diagnostic
Reports a diagnostic at sourceRange, with message arguments and contextMessages.
inherited
reportAtToken(Token token, {List<Object> arguments = const [], List<DiagnosticMessage>? contextMessages}) → Diagnostic?
Reports a diagnostic at token, with message arguments and contextMessages.
inherited
runWithReporter(SaropaDiagnosticReporter reporter, SaropaContext context) → void
Override this method to implement your lint rule.
override
shouldSkipFile(String path) → bool
Check if a file path should be skipped based on context settings.
inherited
toString() → String
A string representation of this object.
inherited

Operators

operator ==(Object other) → bool
The equality operator.
inherited