@thisisagile/easy/src/data/Condition.ts

Straightforward library for building domain-driven microservice architectures

import { json, Json, JsonValue } from '../types/Json';
import { Sort } from '../types/Sort';
import { convert, Convert } from '../utils/Convert';
import { isDefined } from '../types/Is';

export class Condition {
  constructor(
    readonly key: string,
    readonly operator: string,
    readonly value: unknown
  ) {}

  and = (...others: Condition[]): LogicalCondition => new LogicalCondition('and', [this, ...others]);
  or = (...others: Condition[]): LogicalCondition => new LogicalCondition('or', [this, ...others]);

  toJSON(): Json {
    return { [this.key]: { [`$${this.operator}`]: json.parse(this.value) } };
  }
}

export class LogicalCondition {
  constructor(
    readonly operator: string,
    readonly conditions: Condition[]
  ) {}

  toJSON(): Json {
    return { [`$${this.operator}`]: this.conditions.map(c => c.toJSON()) };
  }
}

export class SortCondition extends Condition implements Sort {
  constructor(
    readonly key: string,
    readonly value: -1 | 1
  ) {
    super(key, '', value);
  }

  toJSON(): Json {
    return { [this.key]: this.value };
  }
}

export const toCondition = (field: string, operator: string, value: unknown, conv: Convert = convert.default): Condition =>
  new Condition(field, operator, conv.from(value) as JsonValue);

export const isSortCondition = (s?: unknown): s is SortCondition => isDefined(s) && s instanceof SortCondition;