I've tried to apply this rule to my elm project's code, but the result of elm-review --fix does not compile.
The code in question can be found at https://github.com/jerith666/elbum/tree/no-redundant-concat-fix-causes-bad-syntax/src/client. If you accept all, or any one of, the fixes it proposes for the rootDiv function at lines 64-84, the result does not compile.