Function extendLogScale
has a Cognitive Complexity of 11 (exceeds 5 allowed). Consider refactoring. Open
function extendLogScale(scale) {
var d3ScaleCopy = scale.copy;
// NOTE: D3 log scale ticks count is not configurable
// and returns 10 ticks per each exponent.
- Read upRead up
Cognitive Complexity
Cognitive Complexity is a measure of how difficult a unit of code is to intuitively understand. Unlike Cyclomatic Complexity, which determines how difficult your code will be to test, Cognitive Complexity tells you how difficult your code will be to read and comprehend.
A method's cognitive complexity is based on a few simple rules:
- Code is not considered more complex when it uses shorthand that the language provides for collapsing multiple statements into one
- Code is considered more complex for each "break in the linear flow of the code"
- Code is considered more complex when "flow breaking structures are nested"
Further reading
Function extendLogScale
has 28 lines of code (exceeds 25 allowed). Consider refactoring. Open
function extendLogScale(scale) {
var d3ScaleCopy = scale.copy;
// NOTE: D3 log scale ticks count is not configurable
// and returns 10 ticks per each exponent.
Similar blocks of code found in 2 locations. Consider refactoring. Open
isInDomain(x) {
var domain = this.domain();
var min = domain[0];
var max = domain[domain.length - 1];
return (!Number.isNaN(min) && !Number.isNaN(max) && (x <= max) && (x >= min));
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 96.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Similar blocks of code found in 2 locations. Consider refactoring. Open
domain = [
Math.min(...[min, domain[0]].filter(Number.isFinite)),
Math.max(...[max, domain[1]].filter(Number.isFinite))
];
- Read upRead up
Duplicated Code
Duplicated code can lead to software that is hard to understand and difficult to change. The Don't Repeat Yourself (DRY) principle states:
Every piece of knowledge must have a single, unambiguous, authoritative representation within a system.
When you violate DRY, bugs and maintenance problems are sure to follow. Duplicated code has a tendency to both continue to replicate and also to diverge (leaving bugs as two similar implementations differ in subtle ways).
Tuning
This issue has a mass of 68.
We set useful threshold defaults for the languages we support but you may want to adjust these settings based on your project guidelines.
The threshold configuration represents the minimum mass a code block must have to be analyzed for duplication. The lower the threshold, the more fine-grained the comparison.
If the engine is too easily reporting duplication, try raising the threshold. If you suspect that the engine isn't catching enough duplication, try lowering the threshold. The best setting tends to differ from language to language.
See codeclimate-duplication
's documentation for more information about tuning the mass threshold in your .codeclimate.yml
.
Refactorings
- Extract Method
- Extract Class
- Form Template Method
- Introduce Null Object
- Pull Up Method
- Pull Up Field
- Substitute Algorithm
Further Reading
- Don't Repeat Yourself on the C2 Wiki
- Duplicated Code on SourceMaking
- Refactoring: Improving the Design of Existing Code by Martin Fowler. Duplicated Code, p76
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var niceTop = parseFloat(Math.ceil(Number(topExp[0])) + 'e' + topExp[1]);
- Read upRead up
- Exclude checks
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 'step' is never reassigned; use 'const' instead of 'var'. Open
var step = Math.ceil(
- Read upRead up
- Exclude checks
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.
Shadowed name: 'd3Scale' Open
var d3Scale = extendLogScale(d3.scaleLog())
- Read upRead up
- Exclude checks
Rule: no-shadowed-variable
Disallows shadowing variable declarations.
Rationale
When a variable in a local scope and a variable in the containing scope have the same name, shadowing occurs. Shadowing makes it impossible to access the variable in the containing scope and obscures to what value an identifier actually refers. Compare the following snippets:
const a = 'no shadow';
function print() {
console.log(a);
}
print(); // logs 'no shadow'.
const a = 'no shadow';
function print() {
const a = 'shadow'; // TSLint will complain here.
console.log(a);
}
print(); // logs 'shadow'.
ESLint has an equivalent rule. For more background information, refer to this MDN closure doc.
Config
You can optionally pass an object to disable checking for certain kinds of declarations.
Possible keys are "class"
, "enum"
, "function"
, "import"
, "interface"
, "namespace"
, "typeAlias"
and "typeParameter"
. You can also pass "underscore
" to ignore variable names that begin with _
.
Just set the value to false
for the check you want to disable.
All checks default to true
, i.e. are enabled by default.
Note that you cannot disable variables and parameters.
The option "temporalDeadZone"
defaults to true
which shows errors when shadowing block scoped declarations in their
temporal dead zone. When set to false
parameters, classes, enums and variables declared
with let
or const
are not considered shadowed if the shadowing occurs within their
temporal dead zone.
The following example shows how the "temporalDeadZone"
option changes the linting result:
function fn(value) {
if (value) {
const tmp = value; // no error on this line if "temporalDeadZone" is false
return tmp;
}
let tmp = undefined;
if (!value) {
const tmp = value; // this line always contains an error
return tmp;
}
}
Examples
"no-shadowed-variable": true
"no-shadowed-variable": true,[object Object]
Schema
{
"type": "object",
"properties": {
"class": {
"type": "boolean"
},
"enum": {
"type": "boolean"
},
"function": {
"type": "boolean"
},
"import": {
"type": "boolean"
},
"interface": {
"type": "boolean"
},
"namespace": {
"type": "boolean"
},
"typeAlias": {
"type": "boolean"
},
"typeParameter": {
"type": "boolean"
},
"temporalDeadZone": {
"type": "boolean"
},
"underscore": {
"type": "boolean"
}
}
}
For more information see this page.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var min = Number.isFinite(props.min) ? props.min : domain[0];
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var domain = this.vars;
- Read upRead up
- Exclude checks
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 'copy' is never reassigned; use 'const' instead of 'var'. Open
var copy = d3ScaleCopy.call(scale);
- Read upRead up
- Exclude checks
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.
Identifier 'top' is never reassigned; use 'const' instead of 'var'. Open
var top = Math.max(...absDomain);
- Read upRead up
- Exclude checks
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.
Identifier 'lowExp' is never reassigned; use 'const' instead of 'var'. Open
var lowExp = low.toExponential().split('e');
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var lowExp = Math.floor(log10(extent[0]));
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var copy = d3ScaleCopy.call(scale);
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var top = Math.max(...absDomain);
- Read upRead up
- Exclude checks
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 'lowExp' is never reassigned; use 'const' instead of 'var'. Open
var lowExp = Math.floor(log10(extent[0]));
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var max = Number.isFinite(props.max) ? props.max : domain[1];
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var max = domain[domain.length - 1];
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var topExp = Math.ceil(log10(extent[1]));
- Read upRead up
- Exclude checks
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 'min' is never reassigned; use 'const' instead of 'var'. Open
var min = domain[0];
- Read upRead up
- Exclude checks
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.
Identifier 'domain' is never reassigned; use 'const' instead of 'var'. Open
var domain = this.vars;
- Read upRead up
- Exclude checks
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.
Identifier 'topExp' is never reassigned; use 'const' instead of 'var'. Open
var topExp = Math.ceil(log10(extent[1]));
- Read upRead up
- Exclude checks
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.
Identifier 'props' is never reassigned; use 'const' instead of 'var'. Open
var props = this.scaleConfig;
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var low = Math.min(...absDomain);
- Read upRead up
- Exclude checks
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 'max' is never reassigned; use 'const' instead of 'var'. Open
var max = Number.isFinite(props.max) ? props.max : domain[1];
- Read upRead up
- Exclude checks
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.
Identifier 'ticksPerExp' is never reassigned; use 'const' instead of 'var'. Open
var ticksPerExp = 10;
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var min = domain[0];
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var extent = d3.extent(scale.domain()) as [number, number];
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var isPositive = domain[0] > 0;
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var d3Scale = extendLogScale(d3.scaleLog())
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var step = Math.ceil(
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var topExp = top.toExponential().split('e');
- Read upRead up
- Exclude checks
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 'isPositive' is never reassigned; use 'const' instead of 'var'. Open
var isPositive = domain[0] > 0;
- Read upRead up
- Exclude checks
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.
Identifier 'niceLow' is never reassigned; use 'const' instead of 'var'. Open
var niceLow = parseFloat(Math.floor(Number(lowExp[0])) + 'e' + lowExp[1]);
- Read upRead up
- Exclude checks
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.
Identifier 'domain' is never reassigned; use 'const' instead of 'var'. Open
var domain = this.domain();
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var domain = d3.extent(this.vars);
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var domain = this.domain();
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var ticksPerExp = 10;
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var lowExp = low.toExponential().split('e');
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var niceLow = parseFloat(Math.floor(Number(lowExp[0])) + 'e' + lowExp[1]);
- Read upRead up
- Exclude checks
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 'absDomain' is never reassigned; use 'const' instead of 'var'. Open
var absDomain = domain.map((d) => Math.abs(d));
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var absDomain = domain.map((d) => Math.abs(d));
- Read upRead up
- Exclude checks
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.
non-arrow functions are forbidden Open
scale.ticks = function (n) {
- Read upRead up
- Exclude checks
Rule: only-arrow-functions
Disallows traditional (non-arrow) function expressions.
Note that non-arrow functions are allowed if 'this' appears somewhere in its body (as such functions cannot be converted to arrow functions).
Rationale
Traditional functions don't bind lexical scope, which can lead to unexpected behavior when accessing 'this'.
Config
Two arguments may be optionally provided:
-
"allow-declarations"
allows standalone function declarations. -
"allow-named-functions"
allows the expressionfunction foo() {}
but notfunction() {}
.
Examples
"only-arrow-functions": true
"only-arrow-functions": true,allow-declarations,allow-named-functions
Schema
{
"type": "array",
"items": {
"type": "string",
"enum": [
"allow-declarations",
"allow-named-functions"
]
},
"minLength": 0,
"maxLength": 1
}
For more information see this page.
Identifier 'min' is never reassigned; use 'const' instead of 'var'. Open
var min = Number.isFinite(props.min) ? props.min : domain[0];
- Read upRead up
- Exclude checks
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.
Identifier 'extent' is never reassigned; use 'const' instead of 'var'. Open
var extent = d3.extent(scale.domain()) as [number, number];
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var props = this.scaleConfig;
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var d3ScaleCopy = scale.copy;
- Read upRead up
- Exclude checks
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 'ticks' is never reassigned; use 'const' instead of 'var'. Open
var ticks = [];
- Read upRead up
- Exclude checks
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.
Identifier 'low' is never reassigned; use 'const' instead of 'var'. Open
var low = Math.min(...absDomain);
- Read upRead up
- Exclude checks
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.
non-arrow functions are forbidden Open
scale.copy = function () {
- Read upRead up
- Exclude checks
Rule: only-arrow-functions
Disallows traditional (non-arrow) function expressions.
Note that non-arrow functions are allowed if 'this' appears somewhere in its body (as such functions cannot be converted to arrow functions).
Rationale
Traditional functions don't bind lexical scope, which can lead to unexpected behavior when accessing 'this'.
Config
Two arguments may be optionally provided:
-
"allow-declarations"
allows standalone function declarations. -
"allow-named-functions"
allows the expressionfunction foo() {}
but notfunction() {}
.
Examples
"only-arrow-functions": true
"only-arrow-functions": true,allow-declarations,allow-named-functions
Schema
{
"type": "array",
"items": {
"type": "string",
"enum": [
"allow-declarations",
"allow-named-functions"
]
},
"minLength": 0,
"maxLength": 1
}
For more information see this page.
Identifier 'max' is never reassigned; use 'const' instead of 'var'. Open
var max = domain[domain.length - 1];
- Read upRead up
- Exclude checks
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.
Identifier 'topExp' is never reassigned; use 'const' instead of 'var'. Open
var topExp = top.toExponential().split('e');
- Read upRead up
- Exclude checks
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.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var ticks = [];
- Read upRead up
- Exclude checks
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 'd3ScaleCopy' is never reassigned; use 'const' instead of 'var'. Open
var d3ScaleCopy = scale.copy;
- Read upRead up
- Exclude checks
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.
Identifier 'd3Scale' is never reassigned; use 'const' instead of 'var'. Open
var d3Scale = extendLogScale(d3.scaleLog())
- Read upRead up
- Exclude checks
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.
Identifier 'niceTop' is never reassigned; use 'const' instead of 'var'. Open
var niceTop = parseFloat(Math.ceil(Number(topExp[0])) + 'e' + topExp[1]);
- Read upRead up
- Exclude checks
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.