31 lines
851 B
Plaintext
31 lines
851 B
Plaintext
// @flow
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const isProduction: boolean = process.env.NODE_ENV === 'production';
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export default function warning(condition: mixed, message: string): void {
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// don't do anything in production
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// wrapping in production check for better dead code elimination
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if (!isProduction) {
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// condition passed: do not log
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if (condition) {
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return;
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}
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// Condition not passed
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const text: string = `Warning: ${message}`;
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// check console for IE9 support which provides console
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// only with open devtools
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if (typeof console !== 'undefined') {
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console.warn(text);
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}
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// Throwing an error and catching it immediately
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// to improve debugging
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// A consumer can use 'pause on caught exceptions'
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// https://github.com/facebook/react/issues/4216
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try {
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throw Error(text);
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} catch (x) {}
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}
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}
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