FSCodeStyle

This repository contains a set of linting rules for TypeScript React projects. These are the same rules used by Flagship. If you're developing a project using Flagship, we recommend enforcing these rules.

Pre-Requisites

Your project must have the following:

• A tsconfig.json file indicating the root files and base directories for the TypeScript compiler

Usage

1. Add a dependency in your project yarn add @brandingbrand/fscodestyle
2. Add a lint script to your package.json "lint": "fscodestyle"

We recommend you set this up as a precommit hook using Husky

Linting

The linter uses tslint. In addition, the following rule extensions have been added:

• tslint-eslint-rules - adds missing eslint rules to tslint
• tslint-react - adds React rules to tslint

Highlights

• Indentation: 2 spaces
• Maximum line length: 100 characters
• No more than two consecutive empty lines
• No trailing whitespace at the end of lines
• Use let and const instead of var
• Use single quotes for string literals
• Use === and !== instead of == and !=
• TypeScript: Use const x: T = { ... }; notation instead of const x = { ...} as T;
• TypeScript: Use interfaces over type literals

Rules in Depth

Name	Description	Package
arrow-parens	Arrow functions with multiple arguments must use parentheses; single arguments must not.	tslint
no-unnecessary-type-assertion	Warn if a type assertion is not necessary for an expression	tslint
typedef	Requires type definitions to exist. Checks function return types, parameters, and member variable declarations.	tslint
typedef-whitespace	Requires no space to exist to the left of the colon in a type definition	tslint
await-promise	Warns if an awaited value is not a promise.	tslint
no-floating-promises	Requires promises returned by functions to be handled appropriately.	tslint
no-inferred-empty-object-type	Disallow type inference of {} (empty object type) at function and constructor call sites	tslint
no-unbound-method	Disallow use of an unbound class method as a callback	tslint
no-unused-variable	Disallows unused imports, variables, functions, and private class members	tslint
use-default-type-parameter	Warns if an explicitly specified type argument is the default for that type parameter.	tslint
no-mergeable-namespace	Disallows mergeable namespaces in the same file.	tslint
array-type	Enforces use of T[] for array types	tslint
no-boolean-literal-compare	Warns on comparison to a boolean literal, as in x === true.	tslint
type-literal-delimiter	Checks that type literal members are separated by semicolons. Enforces a trailing semicolon for multiline type literals.	tslint
trailing-comma	Disallow trailing commas	tslint
no-constant-condition	Disallow use of constant expressions in conditions	tslint
cyclomatic-complexity	Allow maximum cyclomatic complexity of 10	tslint
switch-default	Require default case in switch statements	tslint
triple-equals	Require use of === and !==	tslint
guard-for-in	Make sure for-in loops have an if statement	tslint
no-switch-case-fall-through	Disallow fallthrough of case statements	tslint
no-magic-numbers	Disallow use of magic numbers except -1, 0, 1, 2, 100, 1000	tslint
no-duplicate-variable	Disallow declaring the same variable more than once	tslint
no-use-before-declare	Disallow use of variables before they are defined	tslint
variable-name	Require camel-cace names	tslint
linebreak-style	Enforce Unix-style linebreaks	tslint
no-consecutive-blank-lines	Disallow more than two consecutive blank lines	tslint
no-trailing-spaces	Disallow trailing whitespace at end of lines	tslint
one-variable-per-declaration	Require no more than one variable declaration per function	tslint
object-literal-key-quotes	Require quotes around object literal property names as needed	tslint
quotemark	Require single quotes for string literal	tslint
semicolon	Require semicolons	tslint
comment-format	Require that single-line comments begin with a space after the //	tslint
no-control-regex	Disallow control characters in regular expressions (recommended)	tslint-eslint-rules
no-duplicate-case	Disallow duplicate case labels in a switch statement	tslint-eslint-rules
no-empty-character-class	Disallow the use of empty character classes in regular expressions	tslint-eslint-rules
no-ex-assign	Disallow assigning to the expection in a catch block	tslint-eslint-rules
no-extra-semi	Disallow unnecessary semicolons	tslint-eslint-rules
no-inner-declarations	Disallow function declarations in nested blocks	tslint-eslint-rules
no-invalid-regexp	Disallow invalid regular expression strings in the RegExp constructor	tslint-eslint-rules
ter-no-irregular-whitespace	Disallow irregular whitespace	tslint-eslint-rules
no-regex-spaces	Disallow multiple spaces in a regular expression literal	tslint-eslint-rules
no-unexpected-multiline	Disallow code that looks like two expressions but is actually one	tslint-eslint-rules
valid-jsdoc	Enforce valid JSDoc comments	tslint-eslint-rules
valid-typeof	Ensure that the results of typeof are compared against a valid string	tslint-eslint-rules
no-multi-spaces	Disallow use of multiple spaces	tslint-eslint-rules
handle-callback-err	Enforce error handling in callbacks	tslint-eslint-rules
array-bracket-spacing	Disallow after and before array brackets	tslint-eslint-rules
block-spacing	Require spacies inside of single line blocks	tslint-eslint-rules
brace-style	Require "one true brace style" in which the opening brace of a block is placed on the same line as its statement or declaration	tslint-eslint-rules
ter-func-call-spacing	Require spacing between function identifiers and their incovations	tslint-eslint-rules
ter-indent	Enforce consistent indentation: 2 spaces	tslint-eslint-rules
ter-max-len	Enforce max line length of 100	tslint-eslint-rules