Single Responsibility Principle(SRP)
Kanuni hii inasema kwamba darasa linapaswa kuwa na sababu moja tu ya kubadilika, ikimaanisha kuwa kila darasa linapaswa kufanya kazi maalum.
Mfano: Kudhibiti data ya mtumiaji na kutuma email arifa.
class UserManager {
constructor() {}
createUser(userData) {
// Logic for creating a user
}
}
class EmailService {
constructor() {}
sendEmail(emailData) {
// Logic for sending an email
}
}
Open/Closed Principle(OCP)
Kanuni hii inahimiza kupanua utendakazi kwa kuongeza msimbo mpya badala ya kurekebisha msimbo uliopo.
Mfano: Kushughulikia mbinu tofauti za malipo katika programu ya biashara ya mtandaoni.
class PaymentProcessor {
processPayment() {
// Common logic for payment processing
}
}
class CreditCardPaymentProcessor extends PaymentProcessor {
processPayment() {
// Logic for processing credit card payment
}
}
class PayPalPaymentProcessor extends PaymentProcessor {
processPayment() {
// Logic for processing PayPal payment
}
}
Liskov Substitution Principle(LSP)
Kanuni hii inadai kuwa vipengee vya darasa linalotokana vinapaswa kubadilishwa kwa vitu vya darasa la msingi bila kuathiri usahihi wa programu.
Mfano: Kusimamia maumbo ya kijiometri.
class Shape {
area() {}
}
class Rectangle extends Shape {
constructor(width, height) {}
area() {
return this.width * this.height;
}
}
class Square extends Shape {
constructor(side) {}
area() {
return this.side * this.side;
}
}
Kanuni ya Utengano wa kiolesura(ISP)
Kanuni hii inashauri kuvunja miingiliano kuwa ndogo ili kuzuia kulazimisha madarasa kutekeleza njia ambazo hazihitaji.
Mfano: Violesura vya kusasisha na kuonyesha data.
class UpdateableFeature {
updateFeature() {}
}
class DisplayableFeature {
displayFeature() {}
}
Dependency Inversion Principle(DIP)
Kanuni hii inaonyesha kuwa moduli za kiwango cha juu hazipaswi kutegemea moduli za kiwango cha chini; zote mbili zinapaswa kutegemea vifupisho.
Mfano: Kutumia dependency injection kudhibiti utegemezi.
class OrderProcessor {
constructor(dbConnection, emailService) {
this.dbConnection = dbConnection;
this.emailService = emailService;
}
}
Kumbuka, mifano hii ni vielelezo tu vya jinsi ya kutumia SOLID kanuni katika Node.js. Kwa vitendo, utahitaji kuzitumia kwa urahisi kulingana na madhumuni na ukubwa wa mradi wako.