Below are all of the lints currently supported in duck.
| Tag | Default Level | Explanation |
|---|---|---|
| accessor_alternative | LintLevel::Warn | GML offers accessors as an alternative to many common functions which are preferable for their readability and brevity. |
| and_preference | LintLevel::Allow | GML supports both and and && to refer to logical "and". Consistent use of one over the other yields cleaner code. |
| anonymous_constructor | LintLevel::Allow | Constructors should be reserved for larger, higher scoped types. |
| bool_equality | LintLevel::Allow | Comparing a bool with a bool literal is more verbose than neccesary. |
| casing_rules | LintLevel::Allow | Like any programming language, GML contains many different symbols that all can be styled in different ways. Picking consistent rules for each type creates a cleaner and more consistent codebase. |
| collapsable_if | LintLevel::Warn | If statements that contain nothing more than another if statement can be collapsed into a single statement. |
| condition_wrapper | LintLevel::Allow | Parenthesis surrounding certain statement expressions are optional in GML, resulting in differing opinions on whether or not to use them. You can select either option via the config. |
| deprecated | LintLevel::Warn | Deprecated features are liable to be removed at any time and should be avoided. |
| draw_sprite | LintLevel::Allow | Projects that implement their own rendering backend may wish to be restrictive around when and where the draw_sprite functions are called. |
| draw_text | LintLevel::Allow | Projects that implement their own UI frameworks / localization may wish to be restrictive around when and where the draw_text functions are called. |
| english_flavor_violation | LintLevel::Allow | GML has many duplicated function names for the sake of supporting both British and American spelling. For consistency, codebases should stick to one. |
| exit | LintLevel::Allow | return can always be used in place of exit, which provides more consistency across your codebase. |
| global | LintLevel::Allow | While useful at times, global variables reduce saftey since they can be accessed or mutated anywhere, and provide no guarentee that they've already been initiailized. |
| invalid_assignment | LintLevel::Deny | Certain assignment patterns are valid in gml but are undefined behavior and have no valid use cases. |
| invalid_comparison | LintLevel::Deny | Certain types allow comparison checks in gml but are undefined behavior and have no valid use cases. |
| invalid_equality | LintLevel::Deny | Certain types allow equality checks in gml but are undefined behavior and have no valid use cases. |
| missing_case_member | LintLevel::Warn | Switch statements matching over an enum typically want to cover all possible cases if they do not implement a default case. |
| missing_default_case | LintLevel::Allow | Switch statements are often used to express all possible outcomes of a limited data set, but by not implementing a default case, no code will run to handle any alternate or unexpected values. |
| mod_preference | LintLevel::Allow | GML supports both mod and % to perform modulo division. Consistent use of one over the other yields cleaner code. |
| multi_var_declaration | LintLevel::Allow | While GML allows you to create multiple local variables at once, it can often lead to confusing syntax that would read better with each variable seperated. |
| non_constant_default_parameter | LintLevel::Warn | Expressive default parameters are not supported in most languages due to their instability and tendency to hide important logic execution from the caller. |
| non_simplified_expression | LintLevel::Warn | Operating on two constant numbers can be reduced for brevity. |
| not_preference | LintLevel::Allow | GML supports both not and ! to refer to unary "not". Consistent use of one over the other yields cleaner code. |
| or_preference | LintLevel::Allow | GML supports both or and ` |
| room_goto | LintLevel::Allow | Projects that implement their own frameworks for room management may wish to be restrictive around when and where the room_goto functions are called. |
| show_debug_message | LintLevel::Allow | Projects often implement their own logging framework and wish to avoid unwrapped prints to the console. |
| single_equals_comparison | LintLevel::Warn | The single-equals token can be used for both assignments and equalities in gml. This is atypical of most languages, and can lead to inconsistancies or bugs in projects. |
| single_switch_case | LintLevel::Warn | Switch statements that only match on a single element can be reduced to an if statement. |
| suspicious_constant_usage | LintLevel::Deny | Using a constant outside of equalities and direct assignments is likely unintended or misunderstood code. |
| switch_without_case | LintLevel::Warn | A switch statement is unncessary if it contains now cases. |
| todo | LintLevel::Allow | Todo markers are useful for work-in-progress code, but often are not intended to be permanently in place. |
| too_many_arguments | LintLevel::Warn | Functions with lots of parameters quickly become confusing and indicate a need for structural change. |
| try_catch | LintLevel::Allow | GML's try/catch will collect all errors as opposed to the precise ones wanted, allowing them to accidently catch errors that should not be surpressed. |
| unassigned_constructor | LintLevel::Warn | Invoking a constructor function without saving the new struct is often a mistake. If the constructor is saving a refernce of itself within its own declaration, this should still be given a wrapper function so that the behavior is not hidden. Avoiding this as an intentional pattern allows this lint to better alert you to mistakes. |
| unnecessary_grouping | LintLevel::Warn | Parenthesis around an expression that do not change how the logic is executed are redundant and can be removed. |
| useless_function | LintLevel::Deny | Anonymous functions that are not assigned to a variable can never be referenced. |
| var_prefix_violation | LintLevel::Allow | It is common practice in GML to prefix local variables (longer than one charcter) with an underscore as it helps to visually distinguish them from instance (or global) variables. You can select either option via the config. |
| with_loop | LintLevel::Allow | The with loop allows your code's context to suddenly change, both making it more difficult to read (as a given line of code is no longer promised to be executing in the scope expected from the file), but also making it more difficult to track down all of the places an object is modified. |