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93 lines
1.5 KiB
Text
93 lines
1.5 KiB
Text
---
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description: 'Require each enum member value to be explicitly initialized.'
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---
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> 🛑 This file is source code, not the primary documentation location! 🛑
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>
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> See **https://typescript-eslint.io/rules/prefer-enum-initializers** for documentation.
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This rule recommends having each `enum`s member value explicitly initialized.
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`enum`s are a practical way to organize semantically related constant values. However, by implicitly defining values, `enum`s can lead to unexpected bugs if it's modified without paying attention to the order of its items.
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## Rule Details
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`enum`s infers sequential numbers automatically when initializers are omitted:
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```ts
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enum Status {
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Open, // infer 0
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Closed, // infer 1
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}
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```
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If a new member is added to the top of `Status`, both `Open` and `Closed` would have its values altered:
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```ts
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enum Status {
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Pending, // infer 0
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Open, // infer 1
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Closed, // infer 2
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}
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```
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Examples of code for this rule:
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<!--tabs-->
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### ❌ Incorrect
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```ts
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enum Status {
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Open = 1,
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Close,
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}
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enum Direction {
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Up,
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Down,
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}
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enum Color {
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Red,
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Green = 'Green'
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Blue = 'Blue',
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}
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```
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### ✅ Correct
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```ts
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enum Status {
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Open = 'Open',
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Close = 'Close',
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}
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enum Direction {
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Up = 1,
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Down = 2,
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}
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enum Color {
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Red = 'Red',
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Green = 'Green',
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Blue = 'Blue',
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}
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```
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## Options
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```jsonc
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// .eslintrc.json
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{
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"rules": {
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"@typescript-eslint/prefer-enum-initializers": "warn"
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}
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}
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```
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This rule is not configurable.
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## When Not To Use It
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If you don't care about `enum`s having implicit values you can safely disable this rule.
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