GenerateUniqueFirstName Class — drizzle-orm Architecture

Source Code

drizzle-seed/src/services/Generators.ts lines 1599–1637

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

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

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

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

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

		this.state = { genIndicesObj };
	}

	generate() {
		// names dataset contains about 30000 unique names.
		if (this.state === undefined) {
			throw new Error('state is not defined.');
		}

		const nameIdx = this.state.genIndicesObj.generate() as number;
		const name = firstNames[nameIdx] as string;

		return name;
	}
}