empty_map_pattern
A map pattern must have at least one entry.
Description
#The analyzer produces this diagnostic when a map pattern is empty.
Example
#The following code produces this diagnostic because the map pattern is empty:
dart
void f(Map<int, String> x) {
if (x case {}) {}
}
Common fixes
#If the pattern should match any map, then replace it with an object pattern:
dart
void f(Map<int, String> x) {
if (x case Map()) {}
}
If the pattern should only match an empty map, then check the length in the pattern:
dart
void f(Map<int, String> x) {
if (x case Map(isEmpty: true)) {}
}
Unless stated otherwise, the documentation on this site reflects Dart 3.7.3. Page last updated on 2025-05-08. View source or report an issue.