kist/ts/core/abstract/AbstractValidator.ts

Package Pipeline Processor

// ============================================================================
// Import
// ============================================================================

import { AbstractProcess } from "../abstract/AbstractProcess";

// ============================================================================
// Class
// ============================================================================

/**
 * AbstractValidator provides a base class for validation.
 * Extends AbstractProcess for consistent logging and validation utility
 * methods.
 * Subclasses should implement the specific `validateProperty` method for
 * custom validation logic.
 */
export abstract class AbstractValidator<T> extends AbstractProcess {
    // Parameters
    // ========================================================================

    // Constructor
    // ========================================================================

    constructor() {
        super();
    }

    // Abstract Methods
    // ========================================================================

    /**
     * Validates an entire object.
     * @param target - The object to validate.
     * @throws Error if validation fails for any property.
     */
    public validate(target: T): void {
        if (!target || typeof target !== "object") {
            throw new Error("Target must be a valid object.");
        }

        for (const key in target) {
            if (Object.prototype.hasOwnProperty.call(target, key)) {
                this.validateProperty(key as keyof T, target[key as keyof T]);
            }
        }

        this.logInfo("Validation completed successfully.");
    }

    /**
     * Validates a specific property of the object.
     * Subclasses must implement this method to provide specific validation logic.
     *
     * @param key - The key of the property being validated.
     * @param value - The value of the property being validated.
     */
    protected abstract validateProperty<K extends keyof T>(
        key: K,
        value: T[K],
    ): void;

    // Validation Methods
    // ========================================================================

    /**
     * Validates a numeric value.
     *
     * @param key - The key being validated.
     * @param value - The numeric value to validate.
     * @throws Error if the value is not a non-negative number.
     */
    protected validateNumber<K extends keyof T>(key: K, value: T[K]): void {
        if (typeof value !== "number" || value < 0) {
            this.throwValidationError(
                key,
                value,
                "Must be a non-negative number.",
            );
        }
    }

    /**
     * Validates a boolean value.
     *
     * @param key - The key being validated.
     * @param value - The boolean value to validate.
     * @throws Error if the value is not a boolean.
     */
    protected validateBoolean<K extends keyof T>(key: K, value: T[K]): void {
        if (typeof value !== "boolean") {
            this.throwValidationError(key, value, "Must be a boolean.");
        }
    }

    /**
     * Validates a string value.
     *
     * @param key - The key being validated.
     * @param value - The string value to validate.
     * @throws Error if the value is not a non-empty string.
     */
    protected validateString<K extends keyof T>(key: K, value: T[K]): void {
        if (typeof value !== "string" || value.trim() === "") {
            this.throwValidationError(
                key,
                value,
                "Must be a non-empty string.",
            );
        }
    }

    /**
     * Validates an object value.
     *
     * @param key - The key being validated.
     * @param value - The object value to validate.
     * @throws Error if the value is not a valid object.
     */
    protected validateObject<K extends keyof T>(key: K, value: T[K]): void {
        if (
            typeof value !== "object" ||
            value === null ||
            Array.isArray(value)
        ) {
            this.throwValidationError(key, value, "Must be a valid object.");
        }
    }

    // Utility Methods
    // ========================================================================

    /**
     * Logs validation success for a property.
     * @param key - The property key.
     * @param value - The value of the property.
     */
    protected logValidationSuccess(key: keyof T, value: T[keyof T]): void {
        const message = `
            Validation successful for property "${String(key)}"
            with value: ${JSON.stringify(value)}
            `;
        this.logSuccess(message);
    }

    /**
     * Throws a standardized validation error.
     *
     * @param key - The key being validated.
     * @param value - The invalid value.
     * @param message - Additional error message.
     * @throws Error with a formatted message.
     */
    protected throwValidationError<K extends keyof T>(
        key: K,
        value: T[K],
        message: string,
    ): void {
        const errorMessage = `
            Validation failed for "${String(key)}"
            with value "${JSON.stringify(value)}".
            ${message}
        `;
        this.logError(errorMessage);
        throw new Error(errorMessage);
    }
}