Known Issues

While Solium is being actively maintained, a few major issues are still lurking around and we thought it best to make you aware of them so you don’t spend time discovering them instead.

  • Solium is currently file-aware instead of being project-aware. What this means is that while linting, Solium doesn’t have the context of all the contracts and how they may be using the contract currently being linted. A consequence of this is that the linter currently flags a state variable as unused if it doesn’t find its usage in the same contract, whereas its clearly possible that you’re import ing the contract elsewhere to use that variable (See issue). This is a fairly critical problem and will be resolved in a future release. We believe a codebase-aware linter would be much more powerful because of its broader context.
  • The linter’s internal parser supports Solidity v0.5. This means that it supports the calldata storage location specifier, but in a non-backward-compatible manner. If you’re currently using Solidity version < 0.5 and have used calldata as a name for a variable or function parameter, you might see false lint issues because calldata is treated as location and hence, the variable name is seen as null. Regardless of whether you use Solium or not, it is a good idea to rename all such variables to keep your code compatible with Solidity 0.5.
  • When installing the Linter from the ethlint NPM package, you might see the following warning:
npm WARN solium-plugin-security@0.1.1 requires a peer of solium@^1.0.0 but none is installed. You must install peer dependencies yourself.

You can safely ignore this warning.

Solium was recently renamed to Ethlint and the linter is available for download from both solium and ethlint NPM packages. Ethlint comes shipped with its Security plugin. This plugin checks to ensure whether solium NPM package is installed or not.

There is currently no way in NPM to allow any one of the specified packages to satisfy as peer dependency, so we can’t specify solium OR ethlint. We also cannot change solium to ethlint in peerDependencies because its a potential breaking change. See the original issue.

  • There is a limitation when using the solium-enable comment directive: You cannot disable all rules (using // solium-disable for example) and then enable a select few (using // solium-enable rule1, rule2 for example). The enabling part doesn’t work and rules remain disabled even after using the enable directive. This is due to how the linter internally represents disabling all rules.

In the below example, the security/no-throw rule will not be enabled on the throw; statement, against the expectations.

contract Foo {
    // solium-disable
    function b11d() {
        // solium-enable security/no-throw