rules:
  - id: init-variables-with-default-value
    message: >-
      Uninitialized variables are assigned with the types default value.
      Explicitly initializing a variable with its default value costs unnecessary gas.
    metadata:
      references:
        - https://github.com/byterocket/c4-common-issues/blob/main/0-Gas-Optimizations.md/#g001---dont-initialize-variables-with-default-value
      category: performance
      technology:
        - solidity
    patterns:
      - pattern-either:
          - pattern: $TYPE $VAR = 0;
          - pattern: $TYPE $VAR = false;
          - pattern: $TYPE $VAR = "";
          - pattern: $TYPE $VAR = '';
      - pattern-not: $TYPE constant $VAR = ...;
      - pattern-not-inside: |
          contract $C {
            ...
            $TYPE immutable $VAR = ...;
            ...
          }
      - pattern-not-inside: |
          function $F(...) {
            ...
          }
    languages:
      - solidity
    severity: INFO