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avoid-js-rounded-ints

Same as avoid_js_rounded_ints in Dart lints

Group: Style
Path: lint/style/avoid-js-rounded-ints
Default: On (recommended)
Origin: Dart lints
Rule: 80 of 512

recommended

Avoid integer literals that JavaScript would round.

Dart compiled to JavaScript stores every int as a 64-bit float, so an integer literal that a double cannot represent exactly silently changes value on the web:

int value = 9007199254740995; // BAD: becomes 9007199254740996 in JavaScript
BigInt value = BigInt.parse('9007199254740995'); // GOOD

Invalid

example.dartdart

int a = 9007199254740993;
int b = 9007199254740995;
int c = -9007199254740993;
int d = 0x20000000000001;
int e = 1234567890123456789;

void use() {
  print(9007199254740997);
  final values = [1, 18014398509481983];
  print(values);
}

Integer literal can't be represented exactly when compiled to JavaScript.

1int a = 9007199254740993;

∙

Integer literal can't be represented exactly when compiled to JavaScript.

1int a = 9007199254740993;

2int b = 9007199254740995;

∙

Integer literal can't be represented exactly when compiled to JavaScript.

2int b = 9007199254740995;

3int c = -9007199254740993;

∙

Integer literal can't be represented exactly when compiled to JavaScript.

3int c = -9007199254740993;

4int d = 0x20000000000001;

∙

Integer literal can't be represented exactly when compiled to JavaScript.

4int d = 0x20000000000001;

5int e = 1234567890123456789;

∙

Integer literal can't be represented exactly when compiled to JavaScript.

7void use() {

8 print(9007199254740997);

∙

Integer literal can't be represented exactly when compiled to JavaScript.

8 print(9007199254740997);

9 final values = [1, 18014398509481983];

∙

Valid

example.dartdart

int a = 9007199254740991;
int b = 9007199254740992;
int c = -9007199254740991;
int d = 0x20000000000000;
int e = 18014398509481984;
int f = 1 << 60;
int g = 42;
double h = 9007199254740993.0;
BigInt i = BigInt.parse('9007199254740993');

Configure avoid-js-rounded-ints

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

falcon.jsonjson

{
  "linter": {
    "rules": {
      "style": {
        "avoid-js-rounded-ints": "error"
      }
    }
  }
}

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

example.dartdart

// falcon-ignore lint/style/avoid-js-rounded-ints: <reason>

avoid-late-keywordavoid-late-keyword
Flags use of the late keyword on variables and fields.
avoid-multiple-declarations-per-lineavoid_multiple_declarations_per_linerecommended
Flags a variable declaration that declares more than one variable.
avoid-non-null-assertionavoid-non-null-assertion
Flags the null-assertion operator ! except on a resolved Map index.
avoid-null-checks-in-equality-operatorsavoid_null_checks_in_equality_operatorsrecommended
Flags null checks of the parameter inside a custom operator ==.
avoid-positional-boolean-parametersavoid_positional_boolean_parameters
Flags a positional bool parameter in a public signature.
avoid-positional-fields-in-recordsavoid_positional_fields_in_records
Flags positional fields in record types.
avoid-private-typedef-functionsavoid_private_typedef_functions
Flags a private function typedef that is used at most once.
avoid-public-notifier-propertiesriverpod
Keeps notifier state behind Riverpod's observable state property.