GenerateUniqueCity Class — drizzle-orm Architecture

Source Code

drizzle-seed/src/services/Generators.ts lines 2374–2409

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

	private state: {
		genIndicesObj: GenerateUniqueInt;
	} | undefined;
	public override isUnique = true;

	override init({ count, seed }: { count: number; seed: number }) {
		if (count > cityNames.length) {
			throw new Error('count exceeds max number of unique cities.');
		}

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

		const genIndicesObj = new GenerateUniqueInt({ minValue: 0, maxValue: cityNames.length - 1 });
		genIndicesObj.init({ count, seed });

		this.state = { genIndicesObj };
	}

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

		const cityIdx = this.state.genIndicesObj.generate() as number;
		const city = cityNames[cityIdx] as string;

		return city;
	}
}