@fimbul/mimir NPM

Mímir

Core rules, formatters and configurations of the Fimbullinter project.

Make sure to also read the full documentation of all available modules.

Purpose

This library contains all core rules, formatters and configuration presets of the Fimbullinter project. It's used internally by Wotan.

Rules

Rule	Description	Difference to TSLint rule / Why you should use it
`await-async-result`	Warns about not using the result of a call to an async function inside async functions. requires type information	TSLint's `no-floating-promises` requires you to specify a list of Promise names, it checks outside of async functions and only requires you to register the `onrejected` callback.
`await-only-promise`	Finds uses of `await` on non-Promise values. Also checks `for await` loops. requires type information	Works for all `PromiseLike` and `Thenable` types out of the box without any configuration.
`generator-require-yield`	Require at least one `yield` inside generator functions.	There's no similar TSLint rule.
`no-debugger`	Ban `debugger;` statements from your production code.	Performance!
`no-fallthrough`	Prevents unintentional fallthough in `switch` statements from one case to another. If the fallthrough is intended, add a comment that matches `/^\s*falls? ?through\b/i`.	Allows more comment variants such as `fallthrough` or `fall through`.
`no-inferred-empty-object`	Warns if a type parameter is inferred as `{}` because the compiler cannot find any inference site.	Really checks every type parameter of function, method and constructor calls. Correctly handles type parameters from JSDoc comments. Recognises type parameter defaults on all merged declarations.
`no-return-await`	Warns for unnecesary `return await foo;` when you can simply `return foo;`	The same as TSLint's rule. I wrote both, but this one is faster.
`no-unreachable-code`	Warns about statements that will never be executed. Works like TypeScript's dead code detection but doesn't fail compilation because it's a lint error.	TSLint removed their `no-unreachable` rule in v4.0.0.
`no-unsafe-finally`	Forbids control flow statements `return`, `throw`, `break` and `continue` inside the `finally` block of a try statement.	Performance!
`no-unstable-api-use`	Finds uses of deprecated and experimental variables, classes, properties, functions, signatures, ... requires type information	This rule checks element accesses (`foo[bar]`), JSX elements, chained function calls (`getFn()()`) in addition to what TSLint's `deprecation` rule does and has more useful error reporting.
`no-unused-expression`	Warns about side-effect free expressions whose value is not used	This one is a bit stricter than TSLint's `no-unused-expression` and checks `for` loops in addition.
`no-unused-label`	Warns about labels that are never used or at the wrong position.	TSLint only has `label-position` which doesn't check for unused labels.
`no-nan-compare`	Don't compare with `NaN`, use `isNaN(number)` or `Number.isNaN(number)` instead.	Performance!
`no-useless-assertion`	Detects type assertions that don't change the type or are not necessary in the first place. requires type information	TSLint's `no-unnecessary-type-assertion` does not detect assertions needed to silence the compiler warning `Variable ... is used before being assigned.` The Wotan builtin rule also checks whether the assertion is necessary at all or the receiver accepts the original type.
`no-useless-initializer`	Detects unnecessary initialization with `undefined`.	TSLint's rule `no-unnecessary-initializer` doesn't fix all parameter initializers and gives false positives for destructuring.
`prefer-dot-notation`	Prefer `obj.foo` over `obj['foo']` where possible.	Same as TSLint's `no-string-literal` rule, but more performant.
`prefer-number-isnan`	Prefer ES2015's `Number.isNaN` over the global `isNaN` mainly for performance. requires type information	No similar rule in TSLint.
`prefer-object-spread`	Prefer object spread over `Object.assign` for copying properties to a new object. requires type information	Performance, and better handling of parens in fixer and avoids false positives that would cause a compile error when fixed.
`syntaxcheck`	Reports syntax errors as lint errors. This rule is not enabled in `wotan:recommended`. requires type information	Used to be part of the deprecated `tslint --type-check`
`trailing-newline`	Requires a line break at the end of each file.	Nothing fancy here :(
`try-catch-return-await`	Companion of `no-return-await` because inside a try-catch block you should await returned promises to correctly enter the catch on rejection and/or the finally block after completion.	TSLint has no similar rule.
`typecheck`	TypeScript's compiler errors as lint errors. This rule is not enabled in `wotan:recommended`. requires type information	Like the deprecated `tslint --type-check` but formatted and can be disabled like any other rule.

Formatters

stylish
json

Configuration Presets

wotan:recommended contains recommended builtin rules. This configuration only adds new rules in major versions.
wotan:latest contains recommended builtin rules and is updated in minor versions. Be aware that this might cause your build to break.