28 lines
677 B
Markdown
28 lines
677 B
Markdown
# warn-once
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Print a warning exactly once during development. Suitable for deprecation warnings, warnings for missing setup etc.
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## Installation
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Open a Terminal in the project root and run:
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```sh
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npm install warn-once
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```
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## Usage
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The `warnOnce` function accepts a condition as the first argument. If the condition is `true`, then it'll print a warning:
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```js
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const warnOnce = require('warn-once');
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// ...
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warnOnce(someCondition, 'This is a warning message');
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```
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You can call `warnOnce` multiple times, but if the warning was printed already, it'll not be printed again.
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The warning is only shown during development, i.e. if `NODE_ENV` is not set to `'production'`.
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