| 1 | // Copyright 2017-2022 @polkadot/util authors & contributors
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| 2 | // SPDX-License-Identifier: Apache-2.0
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| 3 | export const REGEX_HEX_PREFIXED = /^0x[\da-fA-F]+$/;
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| 4 | export const REGEX_HEX_NOPREFIX = /^[\da-fA-F]+$/;
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| 5 | /**
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| 6 | * @name isHex
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| 7 | * @summary Tests for a hex string.
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| 8 | * @description
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| 9 | * Checks to see if the input value is a `0x` prefixed hex string. Optionally (`bitLength` !== -1) checks to see if the bitLength is correct.
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| 10 | * @example
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| 11 | * <BR>
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| 12 | *
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| 13 | * ```javascript
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| 14 | * import { isHex } from '@polkadot/util';
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| 15 | *
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| 16 | * isHex('0x1234'); // => true
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| 17 | * isHex('0x1234', 8); // => false
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| 18 | * ```
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| 19 | */
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| 20 |
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| 21 | export function isHex(value, bitLength = -1, ignoreLength) {
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| 22 | return typeof value === 'string' && (value === '0x' || REGEX_HEX_PREFIXED.test(value)) && (bitLength === -1 ? ignoreLength || value.length % 2 === 0 : value.length === 2 + Math.ceil(bitLength / 4));
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| 23 | } |
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