eslint-plugin-complete/dist/completeCommon.js

An ESLint plugin that contains useful rules.

// We do not want "eslint-plugin-complete" to depend on "complete-common" because it complicates the
// usage of the plugin inside of the monorepo. Specifically, since we manually copy the compiled
// output to the monorepo "node_modules" directory, it would cause errors if the "complete-common"
// directory did not also exist there. To fix this, we could also compile and copy "complete-common"
// in the build script for this plugin. However, that is undesirable for two reasons:
// 1) It increases the complexity of the build script.
// 2) If "complete-common" exists in the monorepo's "node_modules" directory, it can cause bugs due
//    to tooling preferring the "real" directory over the tsconfig "paths" resolution.
const FIRST_LETTER_CAPITALIZED_REGEX = /^\p{Lu}/u;
/**
 * Helper function to throw an error if the provided value is equal to `undefined`.
 *
 * This is useful to have TypeScript narrow a `T | undefined` value to `T` in a concise way.
 */
export function assertDefined(value, ...[msg]) {
    if (value === undefined) {
        throw new TypeError(msg);
    }
}
export function capitalizeFirstLetter(string) {
    if (string === "") {
        return string;
    }
    const firstCharacter = string.charAt(0);
    const capitalizedFirstLetter = firstCharacter.toUpperCase();
    const restOfString = string.slice(1);
    return `${capitalizedFirstLetter}${restOfString}`;
}
/**
 * From:
 * https://stackoverflow.com/questions/8334606/check-if-first-letter-of-word-is-a-capital-letter
 */
export function isFirstLetterCapitalized(string) {
    return FIRST_LETTER_CAPITALIZED_REGEX.test(string);
}
/**
 * Helper function to narrow an unknown value to an object (i.e. a TypeScript record).
 *
 * Under the hood, this checks for `typeof variable === "object"`, `variable !== null`, and
 * `!Array.isArray(variable)`.
 */
export function isObject(variable) {
    return (typeof variable === "object"
        && variable !== null
        && !Array.isArray(variable));
}
/**
 * Helper function to trim a prefix from a string, if it exists. Returns the trimmed string.
 *
 * @param string The string to trim.
 * @param prefix The prefix to trim.
 * @param trimAll Whether to remove multiple instances of the prefix, if they exist. If this is set
 *                to true, the prefix must only be a single character.
 */
export function trimPrefix(string, prefix, trimAll = false) {
    if (trimAll) {
        const regExp = new RegExp(`^${prefix}+`, "g");
        return string.replaceAll(regExp, "");
    }
    if (!string.startsWith(prefix)) {
        return string;
    }
    return string.slice(prefix.length);
}