Questions tagged [typescript]
Programming language created by Microsoft. Open source, and compiles to JavaScript.
110
questions
1
vote
1
answer
20
views
What should I write before the tests in Clean Architecture with TDD?
Well, we all know the main concept of TDD: write a failing test, then implement the testing component to make your test pass.
I've been working on a personal project in Clean Architecture following ...
0
votes
0
answers
30
views
Can the god object antipattern in generic typescript+react forms be avoided with dynamic imports?
Preface
I looked into several other SO posts already, asking the question on how to avoid the god object pattern, but I'm not sure those articles are actually answering my question. E.g.
I do know ...
- 131
-3
votes
1
answer
97
views
Is it a bad practice to pass instance as function parameter? [closed]
So I am learning how to use the factory function in javascript/typescript. I created a to-do list project where I had to pass the instance as a parameter to the function. I wanted to ask is it a bad ...
0
votes
0
answers
66
views
Identify Domain Entities for a search tool interface - Clean Architecture
I am pretty new to Clean Architecture / Onion Achitecture, I actually not sure if the 2 terms are exchangeable.
So it pretty clear to me, considering is a few days I am reading and study about it.
It ...
0
votes
3
answers
86
views
Decoupling command and receiver in command pattern
I'm writing a simulation of a car that can receive commands and act on them and I'm trying to implement it using the command pattern.
class Car {
move() {
console.log('move');
}
}
interface ...
- 9
12
votes
6
answers
4k
views
Is it OK to have type aliases for primitive types in TypeScript?
In a project that my team is working on, we have type aliases for primitive types. The reason, I got from my team, for this is to have consistency across the codebase.
For example:
type FruitName = ...
- 231
0
votes
1
answer
120
views
Changing the generic type when chaining operations
I have a class where I want to chain certain operations. The class look something like this
class MyClass<T> {
create<X>(fn: (_: T) => X): MyClass<X> {
...
...
- 119
-1
votes
2
answers
59
views
What to do when forced to initialize functions in createContext
What do I do in this situation? Do I just initialize dummy functions in place of signup, login, and logout?
It seems so unnecessary since they are defined in AuthProvider.
type AuthContext = {
...
0
votes
1
answer
361
views
Where should interfaces/model definitions live? -- Clean architecture
I'm working on a Node project (in typescript) that features a variation of clean architecture. I have a pretty clear understanding of the different layers of an application and how they depend on each ...
- 111
0
votes
1
answer
164
views
Removing successful cases from SQS batch. Is it wrong?
I have been working on a lambda that is triggered by a SQS with a batch (let's say of 5) and has automatic retry enabled.
The most common problem with this kind of setup that I have seen is that, if ...
- 119
0
votes
1
answer
60
views
Extending TypeScript while being futureproof [closed]
C#10 Has extended the property pattern ability, I think it began since #7
EG:
{ Car: { Interior: pattern } }
Meaning you can do some nice pattern matching even in if statements
if (car_var is ...
- 109
1
vote
1
answer
209
views
Is usage of "global" types in typescript considered bad practice?
I'm fairly new to strongly typed languages, coming from the "jungle" world of JS and PHP. In my current Typescript project(React-Typescript), i'm struggling with a very fundamental question: ...
- 115
1
vote
6
answers
259
views
Liskov Substitution Principle Inconsistency? How to figure out?
Liskov Substitution Principle states:
"if S is a subtype of T, then objects of type T may be replaced with objects of type S without altering any of the desirable properties of the program (...
- 127
1
vote
5
answers
562
views
Clean architecture, Login UseCase with OAuth breaking Single responsability principle
I'm building a login system using OAuth to integrate with various social networks.
The flow is very simple, first, the user is redirected to their social network to grant permission to read the ...
- 383
1
vote
2
answers
173
views
Is it a good/bad practice to create overlapping types?
Here's a simple example: an API returns a list of possible options with the following structure:
{
"familystatus": [
{
"Id": 1,
"Name": "single&...
- 121
4
votes
3
answers
486
views
Steps to achieve the best code quality?
Currently I'm on a project where my objective is to obtain the best code quality.
We have unit, integration & e2e testing. The e2e tests are written by the Business team in cucumber and these ...
- 148
6
votes
6
answers
443
views
Should a Car object be responsible for checking if it is able to run on certain Road objects?
I have 2 kinds of objects in my system, Car and Road.
A Car can be of various types and have properties like tire, tire size, engine, etc.
A Road can be of multiple types and have properties like ...
- 169
0
votes
1
answer
40
views
Pros and Cons of placing a method as static in the class or as private function outside of class when it doesn't utilize this?
I use typescript. When I write the below code ESlint throws this error: https://eslint.org/docs/rules/class-methods-use-this
export class {
constructor() {
const result = doCalculations()
......
- 109
0
votes
1
answer
55
views
How are discriminated unions (e.g. in TS) used in messaging schemes?
In the documentation about discriminated unions in typescript, here it says:
Discriminated unions are useful for more than just talking about
circles and squares. They’re good for representing any ...
- 127
2
votes
1
answer
312
views
When should a variable be declared / Value assigned?
So we have quiet a big TypeScript codebase at work, where each method resides in its own file. Now in a lot of those methods the variables are often declared all together at the top/beginnng of the ...
- 145
0
votes
2
answers
82
views
Language-independent explanation of "registration" by the IoC container
I've been reading quite a lot on the concept of Inversion of Control (IoC) and Dependency Injection (DI), and I've seen that DI often relies on an IoC container, which among other roles has to
...
- 61
5
votes
3
answers
414
views
Qualms over the 'flexibility' advantage of using dependency injection
I'm currently studying dependency injection and I'm having some issues with the so called 'flexibility' advantage of using dependency injection.
The flexibility advantage is mentioned in post ...
- 61
0
votes
1
answer
220
views
Is a "wrong" to return anything else besides `this` in a constructor?
Is a "wrong" to return anything else besides this in a constructor?
Take this TypeScript Queue sample:
class Queue {
private buffer: string;
constructor(buffer: string = "&...
- 395
2
votes
2
answers
448
views
Domain driven design model version
sorry for the long question, but I love DDD but there is a problem I can't seem to resolve.
We have a problem when adding business rules to the aggregate root.
Our architecture is mostly like this ...
- 29
2
votes
0
answers
904
views
Setting width/height of unknown images for lazy loading
I have a site where users upload images & can all be viewed on a single page by other users. I want to lazy load images as the user scrolls instead of loading all initially. This is easy enough, ...
- 151
-1
votes
1
answer
60
views
Angular: send form or object?
My question is about clean code or best practice. I have a big formGroup and in my opinion its more difficult to map the form to an object than to send the form to the backend.
best regards
- 13
3
votes
0
answers
260
views
How do I architect reordering in database?
I'm building a todo list app and using react-beautiful-dnd on the frontend to allow users to reorder tasks. I'm trying to work out how to persist changes to the database when a user reorders items.
...
- 131
2
votes
2
answers
182
views
Should base class include unused properties of sub class?
I was looking at the angular documentation and noticed this code:
export class QuestionBase<T> {
value: T;
key: string;
label: string;
required: boolean;
order: number;
controlType: ...
- 177
0
votes
1
answer
112
views
Use nullable or undefineable as object type?
This come with a debate with my colleague that I'm using nullable object type.
type Value = Node | null
const [v0, setV0] = React.useState<Value>(null)
const [v1, setV1] = React.useState&...
- 539
0
votes
1
answer
92
views
Preferred architecture for tree stuctured data (Angular/Typescript)
After reading some of "Clean Architecture" I got the idea that perhaps I should reconsider the way I have architected a chart of accounts/accounts object in an accounting program.
I have ...
- 103
28
votes
14
answers
9k
views
Ways to explain code when told it doesn't make sense
As a programmer I have found my code frequently elicits the reaction "I don't understand". Whenever I get this response I try my best to explain my code patiently, and not make anyone feel ...
- 430
4
votes
3
answers
1k
views
Testing unexpected inputs for unit tests and loops?
I'm working on an enterprise that has some Angular/Typescript projects and to avoid repeating code (basically copying and pasting) between them, we decided to go for Monorepo and start write an util ...
- 151
2
votes
2
answers
382
views
Database Model Classes in TypeScript
I'm using Knex.js with TypeScript for database access.
Table
uid (UUID, auto-generated by Postgres)
name (varchar)
Model
interface User {
uid: string | null;
name: string;
}...
1
vote
0
answers
359
views
Where to place the Value Object code that is shared by more than one Aggregate Root?
I have 2 Aggregate Root:
One is the Lessor user, and the other is the Lessee user.
class Lessor extends AggregateRoot {}
class Lessee extends AggregateRoot {}
Each of these Aggregate Roots has a ...
- 11
3
votes
1
answer
151
views
Is there a simpler approach than abstract factories for handling similar, but branching, logic?
I have a medium-sized Angular-based web application that I'm currently implementing some permission components for. Overall, the areas where the permissions components will be used are virtually ...
- 1,317
3
votes
1
answer
5k
views
Typescript and Angular 6 - Mapping Service Results to Data Transfer Objects
I think I am just look for a bit of code review advice. It might possibly be a methodology question?
Essentially when I am pulling data (usually from a REST request), I generate a service, then ...
- 403
8
votes
3
answers
1k
views
Naming of union and intersection types in TypeScript
In TypeScript, the following is called a union type:
number | string
and this is called an intersection type:
number & string
However, is the resulting type of the | not actually an intersection,...
- 299
8
votes
1
answer
5k
views
Error handling in Nest service layer
I would like to create a REST API with NestJs. But I want to add GraphQL as another top level layer later on. So for the start I have the basic layers controller, service and TypeORM repository. Let's ...
- 189
3
votes
2
answers
180
views
Should entities have nullable id because they're autoganerated by the database?
Suppose I have a domain entity representing a person. (Examples in TypeScript)
class Person {
constructor(public name: string) {}
}
Now, because other parts of the domain will need to reference ...
- 147
7
votes
1
answer
3k
views
How & Should we use Clean Architecture in Front-end?
Just a little explanation:
"I'm used to be a solo front-end developer in my company and using default folder-structure and way of coding which vue-cli provided, it is good for a solo developer and ...
- 221
2
votes
0
answers
2k
views
Updating nested state with React Hooks and Typescript - performance vs clarity
I have some deeply nested react components. Let's limit them to 3 levels of nesting and call them Parent, Children and Grandchildren. The state for the entire app is stored in a single object in the ...
- 187
0
votes
1
answer
91
views
Is my typescript controller overloaded?
I'm building a rest API using typescript and typeorm as orm. Each route of my API point's to a specific method located in a controller class.
My question is about the content of this controller ...
- 103
2
votes
1
answer
217
views
Web application demo mode or Introduction mode
I have a web-app with multiple functionalities and each functionality has multiple workflow/process. For example, Workflow A has Steps A => Step F, Workflow B has Steps A1 => Steps G1 and many more ...
- 151
1
vote
0
answers
118
views
What to do about compilation errors if ignoring them makes the app run fine?
Updating the libraries in my Angular 8/Electron app produced compilations errors eg, in Electron's menu.ts file, Also, a few of the project external libraries contain @ts-ignore lines, suppressing ...
- 793
4
votes
1
answer
2k
views
Form validation code shared in the frontend and backend API?
I have a legacy Java monolithic web application. My goal is to use React on the frontend, keep Java on the backend and add an API for the frontend to use.
My question is how can I write the data ...
- 41
0
votes
1
answer
261
views
Any possible downsides to namespacing actions for stores
For libraries like NGRX - Actions or NGXS - Actions when creating an action you create an interface or class like so:
bar-action.ts
export class Foo {
static type: string = 'bar-foo';
}
// etc ...
- 290
1
vote
0
answers
109
views
List all interfaces from a TypeScript project
I need to have compiled in a single file all the interfaces that extends a particular interface for doing some refactoring work (long story). I'm using Visual Studio 2019, but I didn't find any ...
- 19
1
vote
2
answers
1k
views
How can I emulate Signals and Slots found in Qt, to Javascript / Typescript Classes?
Ive brought this up with other developers, and they say while there is no obvious way forward, it seems that they all have an idea of how to go about it.
Is there any way I can implement signals and ...
- 3,319
1
vote
0
answers
30
views
Inheritance on nested components
I am creating a grid using ag-grid. Here I want to create custom dynamic cell editors. Which show different edit fields based on the value inside the cell. I got the idea from here.
This question is ...
- 19
3
votes
0
answers
129
views
data transfer objects between abstraction layers
I want to create an Express REST API and want to try following the clean architecture ideas. I was reading about it but didn't get the idea of the communication between the abstraction layers.
Let's ...
- 155