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avoid-complex-loop-conditions

Group: Complexity
Path: lint/complexity/avoid-complex-loop-conditions
Default: Off, opt in
Origin: Falcon
Rule: 36 of 512

Flags loop conditions with more logical operands than the configured threshold.

Checks while, do/while, and C-style for conditions. Each operand joined by && or || counts as one; comparisons and calls are opaque. For-in iterables and for-loop initializers and updates are not conditions.

Options

threshold (integer, default: 1) — maximum number of logical operands.

Invalid

example.dartdart

void f(bool a, bool b, bool c) {
  while (a && b && c) { break; }
  while (a || b || c) { break; }
  do {} while (a && (b || c));
  for (; a && b && c;) { break; }
  for (var i = 0; i < 4 && a && b; i++) {}
  final values = [for (var i = 0; i < 4 && a && b; i++) i];
}

Loop condition has 3 logical operands (max 2). Extract a named condition.

1void f(bool a, bool b, bool c) {

2 while (a && b && c) { break; }

∙

Loop condition has 3 logical operands (max 2). Extract a named condition.

2 while (a && b && c) { break; }

3 while (a || b || c) { break; }

∙

Loop condition has 3 logical operands (max 2). Extract a named condition.

3 while (a || b || c) { break; }

4 do {} while (a && (b || c));

∙

Loop condition has 3 logical operands (max 2). Extract a named condition.

4 do {} while (a && (b || c));

5 for (; a && b && c;) { break; }

∙

Loop condition has 3 logical operands (max 2). Extract a named condition.

5 for (; a && b && c;) { break; }

6 for (var i = 0; i < 4 && a && b; i++) {}

∙

Loop condition has 3 logical operands (max 2). Extract a named condition.

6 for (var i = 0; i < 4 && a && b; i++) {}

7 final values = [for (var i = 0; i < 4 && a && b; i++) i];

∙

Valid

example.dartdart

void f(bool a, bool b, List<bool> items) {
  while (a) { break; }
  while (a && b) { break; }
  do {} while (a || b);
  for (var i = 0; i < 2; i++) {}
  for (final item in items) { if (item && a && b) {} }
  for (;;) { break; }
}

Configure avoid-complex-loop-conditions

Set its severity in falcon.json. See the configuration guide.

falcon.jsonjson

{
  "linter": {
    "rules": {
      "complexity": {
        "avoid-complex-loop-conditions": "error"
      }
    }
  }
}

Or silence one occurrence with a suppression comment; the reason is required.

example.dartdart

// falcon-ignore lint/complexity/avoid-complex-loop-conditions: <reason>

avoid-function-literals-in-foreach-callsavoid_function_literals_in_foreach_calls
Flags a function literal passed to an Iterable's forEach.
avoid-if-with-many-branches
Reports long if/else-if chains; replace them with a switch or extracted helpers.
avoid-inverted-boolean-expressionsavoid_inverted_boolean_expressionsrecommended
Flags a doubly-negated boolean expression such as !!x.
avoid-long-records
Reports record values and record types with too many fields.
avoid-nested-conditional-expressionsavoid-nested-conditional-expressions
Flags a ternary conditional expression nested inside another ternary.
avoid-nested-ifavoid_nested_if
Flags an if statement whose then-branch contains nested if statements.
avoid-nested-switch-expressions
Reports deeply nested switch expressions.
avoid-nested-switches
Reports deeply nested switch statements.