Forbidden 'var' keyword, use 'let' or 'const' instead Open
var alertify = require("alertify.js")
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Rule: no-var-keyword
Disallows usage of the var
keyword.
Use let
or const
instead.
Rationale
Declaring variables using var
has several edge case behaviors that make var
unsuitable for modern code.
Variables declared by var
have their parent function block as their scope, ignoring other control flow statements.
var
s have declaration "hoisting" (similar to function
s) and can appear to be used before declaration.
Variables declared by const
and let
instead have as their scope the block in which they are defined,
and are not allowed to used before declaration or be re-declared with another const
or let
.
Notes
- Has Fix
Config
Not configurable.
Examples
"no-var-keyword": true
For more information see this page.
Identifier 'alertify' is never reassigned; use 'const' instead of 'var'. Open
var alertify = require("alertify.js")
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Rule: prefer-const
Requires that variable declarations use const
instead of let
and var
if possible.
If a variable is only assigned to once when it is declared, it should be declared using 'const'
Notes
- Has Fix
Config
An optional object containing the property "destructuring" with two possible values:
- "any" (default) - If any variable in destructuring can be const, this rule warns for those variables.
- "all" - Only warns if all variables in destructuring can be const.
Examples
"prefer-const": true
"prefer-const": true,[object Object]
Schema
{
"type": "object",
"properties": {
"destructuring": {
"type": "string",
"enum": [
"all",
"any"
]
}
}
}
For more information see this page.
" should be ' Open
var alertify = require("alertify.js")
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Rule: quotemark
Enforces quote character for string literals.
Notes
- Has Fix
Config
Five arguments may be optionally provided:
-
"single"
enforces single quotes. -
"double"
enforces double quotes. -
"backtick"
enforces backticks. -
"jsx-single"
enforces single quotes for JSX attributes. -
"jsx-double"
enforces double quotes for JSX attributes. -
"avoid-template"
forbids single-line untagged template strings that do not contain string interpolations. Note that backticks may still be used if"avoid-escape"
is enabled and both single and double quotes are present in the string (the latter option takes precedence). -
"avoid-escape"
allows you to use the "other" quotemark in cases where escaping would normally be required. For example,[true, "double", "avoid-escape"]
would not report a failure on the string literal'Hello "World"'
.
Examples
"quotemark": true,single,avoid-escape,avoid-template
"quotemark": true,single,jsx-double
Schema
{
"type": "array",
"items": {
"type": "string",
"enum": [
"single",
"double",
"backtick",
"jsx-single",
"jsx-double",
"avoid-escape",
"avoid-template"
]
},
"minLength": 0,
"maxLength": 5
}
For more information see this page.
Missing semicolon Open
var alertify = require("alertify.js")
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Rule: semicolon
Enforces consistent semicolon usage at the end of every statement.
Notes
- Has Fix
Config
One of the following arguments must be provided:
-
"always"
enforces semicolons at the end of every statement. -
"never"
disallows semicolons at the end of every statement except for when they are necessary.
The following arguments may be optionally provided:
-
"ignore-interfaces"
skips checking semicolons at the end of interface members. -
"ignore-bound-class-methods"
skips checking semicolons at the end of bound class methods. -
"strict-bound-class-methods"
disables any special handling of bound class methods and treats them as any other assignment. This option overrides"ignore-bound-class-methods"
.
Examples
"semicolon": true,always
"semicolon": true,never
"semicolon": true,always,ignore-interfaces
"semicolon": true,always,ignore-bound-class-methods
Schema
{
"type": "array",
"items": [
{
"type": "string",
"enum": [
"always",
"never"
]
},
{
"type": "string",
"enum": [
"ignore-interfaces"
]
}
],
"additionalItems": false
}
For more information see this page.