GenerateUniqueFullName Class — drizzle-orm Architecture

Source Code

drizzle-seed/src/services/Generators.ts lines 1758–1821

export class GenerateUniqueFullName extends AbstractGenerator<{
	isUnique?: boolean;
}> {
	static override readonly entityKind: string = 'GenerateUniqueFullName';

	private state: {
		fullnameSet: Set<string>;
		rng: prand.RandomGenerator;
	} | undefined;
	public override isUnique = true;
	public override timeSpent = 0;

	override init({ count, seed }: { count: number; seed: number }) {
		const t0 = new Date();

		const maxUniqueFullNamesNumber = firstNames.length * lastNames.length;
		if (count > maxUniqueFullNamesNumber) {
			throw new RangeError(
				`count exceeds max number of unique full names(${maxUniqueFullNamesNumber}).`,
			);
		}

		if (this.stringLength !== undefined && this.stringLength < (maxFirstNameLength + maxLastNameLength + 1)) {
			throw new Error(
				`You can't use full name generator with a db column length restriction of ${this.stringLength}. Set the maximum string length to at least ${
					maxFirstNameLength + maxLastNameLength + 1
				}.`,
			);
		}

		const rng = prand.xoroshiro128plus(seed);
		const fullnameSet = new Set<string>();

		this.state = { rng, fullnameSet };
		this.timeSpent += (Date.now() - t0.getTime()) / 1000;
	}

	generate() {
		if (this.state === undefined) {
			throw new Error('state is not defined.');
		}

		let fullname: string, name: string, surname: string, idx: number;

		const t0 = new Date();
		for (;;) {
			[idx, this.state.rng] = prand.uniformIntDistribution(0, firstNames.length - 1, this.state.rng);
			name = firstNames[idx] as string;

			[idx, this.state.rng] = prand.uniformIntDistribution(0, lastNames.length - 1, this.state.rng);
			surname = lastNames[idx] as string;

			fullname = `${name} ${surname}`;

			if (!this.state.fullnameSet.has(fullname)) {
				this.state.fullnameSet.add(fullname);
				break;
			}
		}

		this.timeSpent += (Date.now() - t0.getTime()) / 1000;
		return fullname;
	}
}