GenerateSelfRelationsValuesFromArray Class — drizzle-orm Architecture

Source Code

drizzle-seed/src/services/Generators.ts lines 406–442

export class GenerateSelfRelationsValuesFromArray extends AbstractGenerator<{ values: (number | string | boolean)[] }> {
	static override readonly entityKind: string = 'GenerateSelfRelationsValuesFromArray';

	private state: {
		rng: prand.RandomGenerator;
		firstValuesCount: number;
		firstValues: (string | number | boolean)[];
	} | undefined;

	override init({ count, seed }: { count: number; seed: number }) {
		let rng = prand.xoroshiro128plus(seed);

		// generate 15-40 % values with the same value as reference column
		let percent = 30;
		[percent, rng] = prand.uniformIntDistribution(20, 40, rng);
		const firstValuesCount = Math.floor((percent / 100) * count), firstValues: (string | number | boolean)[] = [];

		this.state = { rng, firstValuesCount, firstValues };
	}

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

		const { values } = this.params;
		let idx: number;

		if (i < this.state.firstValuesCount) {
			this.state.firstValues.push(values[i]!);
			return values[i];
		} else {
			[idx, this.state.rng] = prand.uniformIntDistribution(0, this.state.firstValues.length - 1, this.state.rng);
			return this.state.firstValues[idx];
		}
	}
}