Function _loopTasks
has 46 lines of code (exceeds 25 allowed). Consider refactoring. Open
_loopTasks() {
var task: Task;
var duration: number;
var frameDuration = 0;
Function _loopTasks
has a Cognitive Complexity of 11 (exceeds 5 allowed). Consider refactoring. Open
_loopTasks() {
var task: Task;
var duration: number;
var frameDuration = 0;
- 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 _runTask
has 27 lines of code (exceeds 25 allowed). Consider refactoring. Open
_runTask(task: Task) {
var start = performance.now();
if (this._callbacks.error) {
try {
this._result = task.call(null,
Similar blocks of code found in 2 locations. Consider refactoring. Open
if (this._queue.length === 0) {
this.stop();
if (this._callbacks.done) {
this._callbacks.done.call(null,
this._result,
- 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 54.
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
if (
isTimeoutReached &&
(this._queue.length > 0)
) {
this.stop();
- 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 54.
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 frameDuration = 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 duration = (end - start);
- 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 'syncInterval' is never reassigned; use 'const' instead of 'var'. Open
var syncInterval = (this._syncInterval / TaskRunner.runnersInProgress);
- 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.
'Object.assign' returns the first argument. Prefer object spread if you want a new object. Open
this._callbacks = Object.assign(this._callbacks || {}, callbacks);
- Read upRead up
- Exclude checks
Rule: prefer-object-spread
Enforces the use of the ES2018 object spread operator over Object.assign()
where appropriate.
Rationale
Object spread allows for better type checking and inference.
Notes
- Has Fix
Config
Not configurable.
Examples
"prefer-object-spread": true
For more information see this page.
Type assertion using the '<>' syntax is forbidden. Use the 'as' syntax instead. Open
return (id) => (<any>window).cancelIdleCallback(id);
- Read upRead up
- Exclude checks
Rule: no-angle-bracket-type-assertion
Requires the use of as Type
for type assertions instead of <Type>
.
Rationale
Both formats of type assertions have the same effect, but only as
type assertions
work in .tsx
files. This rule ensures that you have a consistent type assertion style
across your codebase.
Notes
- TypeScript Only
- Has Fix
Config
Not configurable.
Examples
"no-angle-bracket-type-assertion": true
For more information see this page.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var task: Task;
- 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 'duration' is never reassigned; use 'const' instead of 'var'. Open
var duration = (end - start);
- 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 'end' is never reassigned; use 'const' instead of 'var'. Open
var end = performance.now();
- 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.
Assignments in conditional expressions are forbidden Open
!(isTimeoutReached = (this._asyncDuration > this._timeout)) &&
- Read upRead up
- Exclude checks
Rule: no-conditional-assignment
Disallows any type of assignment in conditionals.
This applies to do-while
, for
, if
, and while
statements and conditional (ternary) expressions.
Rationale
Assignments in conditionals are often typos:
for example if (var1 = var2)
instead of if (var1 == var2)
.
They also can be an indicator of overly clever code which decreases maintainability.
Config
Not configurable.
Examples
"no-conditional-assignment": true
For more information see this page.
Assignments in conditional expressions are forbidden Open
!(isFrameTimeoutReached = (frameDuration > syncInterval)) &&
- Read upRead up
- Exclude checks
Rule: no-conditional-assignment
Disallows any type of assignment in conditionals.
This applies to do-while
, for
, if
, and while
statements and conditional (ternary) expressions.
Rationale
Assignments in conditionals are often typos:
for example if (var1 = var2)
instead of if (var1 == var2)
.
They also can be an indicator of overly clever code which decreases maintainability.
Config
Not configurable.
Examples
"no-conditional-assignment": true
For more information see this page.
Type assertion using the '<>' syntax is forbidden. Use the 'as' syntax instead. Open
return (<any>window).requestIdleCallback(callback, {timeout: 17});
- Read upRead up
- Exclude checks
Rule: no-angle-bracket-type-assertion
Requires the use of as Type
for type assertions instead of <Type>
.
Rationale
Both formats of type assertions have the same effect, but only as
type assertions
work in .tsx
files. This rule ensures that you have a consistent type assertion style
across your codebase.
Notes
- TypeScript Only
- Has Fix
Config
Not configurable.
Examples
"no-angle-bracket-type-assertion": true
For more information see this page.
Assignments in conditional expressions are forbidden Open
(task = this._queue.shift())
- Read upRead up
- Exclude checks
Rule: no-conditional-assignment
Disallows any type of assignment in conditionals.
This applies to do-while
, for
, if
, and while
statements and conditional (ternary) expressions.
Rationale
Assignments in conditionals are often typos:
for example if (var1 = var2)
instead of if (var1 == var2)
.
They also can be an indicator of overly clever code which decreases maintainability.
Config
Not configurable.
Examples
"no-conditional-assignment": true
For more information see this page.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var isFrameTimeoutReached: boolean;
- 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 duration: 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 start = performance.now();
- 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.
Type assertion on object literals is forbidden, use a type annotation instead. Open
callbacks = {} as TaskRunnerCallbacks
- Read upRead up
- Exclude checks
Rule: no-object-literal-type-assertion
Forbids an object literal to appear in a type assertion expression.
Casting to any
or to unknown
is still allowed.
Rationale
Always prefer const x: T = { ... };
to const x = { ... } as T;
.
The type assertion in the latter case is either unnecessary or hides an error.
The compiler will warn for excess properties with this syntax, but not missing required fields.
For example: const x: { foo: number } = {}
will fail to compile, but
const x = {} as { foo: number }
will succeed.
Additionally, the const assertion const x = { foo: 1 } as const
,
introduced in TypeScript 3.4, is considered beneficial and is ignored by this rule.
Notes
- TypeScript Only
Config
One option may be configured:
-
allow-arguments
allows type assertions to be used on object literals inside call expressions.
Examples
"no-object-literal-type-assertion": true
"no-object-literal-type-assertion": true,[object Object]
Schema
{
"type": "object",
"properties": {
"allow-arguments": {
"type": "boolean"
}
},
"additionalProperties": false
}
For more information see this page.
Forbidden 'var' keyword, use 'let' or 'const' instead Open
var end = performance.now();
- 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 'start' is never reassigned; use 'const' instead of 'var'. Open
var start = performance.now();
- 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 isTimeoutReached: boolean;
- 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 syncInterval = (this._syncInterval / TaskRunner.runnersInProgress);
- 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.