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TYPESCRIPT QUESTIONS

Modifying Property Values in Typescript Decorator
Modifying Property Values in Typescript Decorator
Hope this helps I have class level variable in an Angular Service. I need to prepend some value to the variables value via decorators. How can I achieve?
TAG : typescript
Date : January 12 2021, 01:40 AM , By : user3100096
Is it recommended to publish source files for TypeScript node modules?
Is it recommended to publish source files for TypeScript node modules?
may help you . To start with a credible source: In the TypeScript Publishing guide, the docs seem to only consider bundling declaration files together with the compiled .js files without inclusion of .ts files.Staying with your example package @loopb
TAG : typescript
Date : January 11 2021, 03:28 PM , By : Makroj
Convert callbacks to observable rxjs
Convert callbacks to observable rxjs
will help you I almost resolve my problem by bindNodeCallback and then I wrote my own bindNodeCallback method which can resolve my case with double callbacks.
TAG : typescript
Date : January 11 2021, 03:28 PM , By : user3099144
TypeScript: Return same type as parameter
TypeScript: Return same type as parameter
I wish did fix the issue. formatISODate function expects string value. , Let's make the example even easier.
TAG : typescript
Date : January 11 2021, 03:26 PM , By : user3098884
How to make some fields in object required
How to make some fields in object required
like below fixes the issue Keeping your IUser interface Using Partial, Pick, and Required:
TAG : typescript
Date : January 11 2021, 02:18 PM , By : drummerama
Exporting "mixed" declarations from .d.ts file - Typescript
Exporting "mixed" declarations from .d.ts file - Typescript
This might help you Your types cannot be found, as the package currently uses a wrong types path in package.json. You can change the types field like this:
TAG : typescript
Date : January 11 2021, 02:18 PM , By : user3098753
TypeScript loop over array of tuples
TypeScript loop over array of tuples
it should still fix some issue The real issue is that the type of [['a', 1], ['b', 2]] is not a tuple type at all. It will be the array type (string | number)[][]. So when destructuring x and y will both be string | number. Typescript will only infer
TAG : typescript
Date : January 11 2021, 02:18 PM , By : user3098698
Ensure function signature type depending on value of other parameter
Ensure function signature type depending on value of other parameter
To fix this issue I'm trying to write a function that verifies that a property has a generic type and returns its value. , You can do something like
TAG : typescript
Date : January 11 2021, 11:39 AM , By : user3098352
Why does my outDir contain a (largely duplicate) src dir?
Why does my outDir contain a (largely duplicate) src dir?
Does that help lib\src\index.js is likely a stale output compilation from one of you previous builds, where you also tried to import a file from the parent directory of src. The cause is an implicit rootDir setting in TypeScript compiler options.root
TAG : typescript
Date : January 10 2021, 02:06 PM , By : user3098328
Storybook in Create React App withTypeScript still compiles when component has illegal types
Storybook in Create React App withTypeScript still compiles when component has illegal types
This might help you The reason Storybook still compiles despite type errors is that Babel preset "react-app" from Create React App (CRA) only strips off the TypeScript definitions and emits all files without further compiler checks.react-app / babel-
TAG : typescript
Date : January 10 2021, 02:06 PM , By : user3098237
Typescript: make one of two properties optional
Typescript: make one of two properties optional
wish help you to fix your issue You can use union types to accomplish your task:
TAG : typescript
Date : January 10 2021, 02:06 PM , By : Hasan Ishtiaq
Typescript Types: Type of object value which can be used as index signature
Typescript Types: Type of object value which can be used as index signature
Any of those help V may extend T[K]. But since T is not constrained in any way when you index using item[key] all the compiler will know is that item[key] is of type T[K]. You need to constrain T so that for the key K the value will be of a type comp
TAG : typescript
Date : January 09 2021, 02:14 PM , By : user3097704
How do I combine "Omit" and "Pick"?
How do I combine "Omit" and "Pick"?
this will help Pick retruns an object type containing only the picked properties. So Pick will be { field: { a: string; b: string; } }. You want the type of field, which you can get using an indexed type query A[field](which will be { a: string; b: s
TAG : typescript
Date : January 09 2021, 02:14 PM , By : user3097687
How to get generic type from a method signature return type
How to get generic type from a method signature return type
may help you . The type in this case is a ts.TypeReference, so the number type in the promise will be in the typeArguments array property of the type.
TAG : typescript
Date : January 08 2021, 10:52 AM , By : user3097221
In TypeScript, define a type for any object that has required properties
In TypeScript, define a type for any object that has required properties
should help you out You don't need to do anything special for this. This will define the required property:
TAG : typescript
Date : January 08 2021, 10:52 AM , By : Klattypus
Typescript - Array of extended Classes of specific Parent
Typescript - Array of extended Classes of specific Parent
this will help Use a constructor signature that returns the abstract class instead of the abstract class. The abstract class does not have a constructor in the type system so it won't be valid but any derived class inheriting the abstract class will
TAG : typescript
Date : January 08 2021, 03:18 AM , By : Anonymous
Typing for a getValues + map operation
Typing for a getValues + map operation
help you fix your problem You can use an interface in combination with in keyof like this (called Mapped Types)
TAG : typescript
Date : January 08 2021, 03:18 AM , By : Cy Ko
How to get predefined property from sub-object?
How to get predefined property from sub-object?
I wish did fix the issue. More general case, where you don't know exact type of c, but you want to infer it, would be like this:
TAG : typescript
Date : January 07 2021, 03:08 PM , By : user3096874
How to wait stack to complete before executing code in AWS CDK?
How to wait stack to complete before executing code in AWS CDK?
I think the issue was by ths following , If you're trying to reference 'dynamic' things like the CloudFront distribution Id that will be generated, I would probably try to have 2 different stacks, and have one depend on the other. I'm not sure I unde
TAG : typescript
Date : January 06 2021, 03:17 PM , By : moridinamael
Typescript: What is the difference between an optional and a not optional class member with default value
Typescript: What is the difference between an optional and a not optional class member with default value
wish of those help The difference is that the attribute types are different in terms of optional assignments later on. Hover over those attributes:
TAG : typescript
Date : January 06 2021, 03:27 AM , By : Peter Bengtson
TypeScript type modification when using defaults and object destructuring assignment
TypeScript type modification when using defaults and object destructuring assignment
hope this fix your issue The destructuring statement is introducing a new variable. It doesn't yet have a type unless one is assigned or in this case inferred. Looking at the downcompiled code this becomes even more apparent:
TAG : typescript
Date : January 06 2021, 03:27 AM , By : Chetan
How to Update json object value in array from another array of same json object structure in Typescript
How to Update json object value in array from another array of same json object structure in Typescript
it helps some times You can do this with a simple map operation and a nested find operation.
TAG : typescript
Date : January 05 2021, 11:29 AM , By : user3095836
How do I specify the correct return type for mapStateToProps?
How do I specify the correct return type for mapStateToProps?
With these it helps Try out the Pick Utility Type Since you're only returning an object with a single property "count" from CounterProps, you should be able to use Pick as the return type for mapStateToProps.
TAG : typescript
Date : January 05 2021, 11:29 AM , By : user3095767
TypeScript's import() typeof json
TypeScript's import() typeof json
hop of those help? Type annotation are by definition erased when the code is compiled to Javascript. Any import type only be used in a type annotation so it will get removed after compilation. You can check this yourself by examining the outputed JS:
TAG : typescript
Date : January 05 2021, 11:29 AM , By : user281342
how to convert a string value to enum in typescript
how to convert a string value to enum in typescript
seems to work fine here's my enum definition , You could try something similar to this:
TAG : typescript
Date : January 02 2021, 10:54 PM , By : user3095272
Can I extract optional properties from a type in Typescript?
Can I extract optional properties from a type in Typescript?
wish of those help I wonder if there is a way to extract only properties which are defined as optional in a given type.
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Mrudula
UnionTypes: PartialRequired and PickRequired
UnionTypes: PartialRequired and PickRequired
hope this fix your issue I'm going to answer the general question about how to programmatically modify an object type to rename keys.Here's one possible implementation that only really works for required, mutable properties with known literal keys (n
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Pascal J
Disable ESLint for TypeScript files
Disable ESLint for TypeScript files
I wish this help you You can try adding *.ts to an .eslintignore. See https://www.jetbrains.com/help/webstorm/2019.2/eslint.htmlws_eslint_suppress_linting_typescript
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Krystian
How to initiate "findInFiles" with VSCode extension API?
How to initiate "findInFiles" with VSCode extension API?
this will help I'm trying to write an extension that will automatically select the word under the cursor, open the find in files dialog, and initiate a search with that selection. So far, I've been able to get the extension to do everything except ac
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Kiran KVS
How to keep ES6 syntax when transpiling with Typescript
How to keep ES6 syntax when transpiling with Typescript
wish of those help Your file tsconfig.json is ignored when you specify app.ts in the command line.In tsconfig.json, add a section exclude after the compiler options:
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Klei Kacmoli
How to transform interface children's type to type[]?
How to transform interface children's type to type[]?
it helps some times You're almost there. Mapped type is what you're looking for:
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Eugene Kozlov
How to transform input data with NestJS and TypeORM
How to transform input data with NestJS and TypeORM
Does that help I want to create functionality where I can transform incoming data before it hits the database. Let's say that we want to make sure that when a new user is created, the firstName and lastName attribute values are always starting with a
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Eduardo Silva
How to use defaultNavigationOptions's properties with TypeScript?
How to use defaultNavigationOptions's properties with TypeScript?
Any of those help The types of react-navigation are very complex. And the usability there is no match to React's types. It took me way too much time to figure the types out and I wish nobody else has to do this again. So here you go. Second argument
TAG : typescript
Date : January 02 2021, 06:48 AM , By : RobbieBert
Unable to create a managed promise instance - if function written with async/await
Unable to create a managed promise instance - if function written with async/await
With these it helps Found the problem. If using async/await syntax asyncF () should return PromiseFor return case we actually return promise.Promise and seems that's why it hasn't been working for the async/await.
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Nils Dehl
TypeScript generics error: Property does not exist on type
TypeScript generics error: Property does not exist on type
hope this fix your issue With you are defining a generic type parameter (one that could be any type). You could define a type parameter with a constraint:
TAG : typescript
Date : January 02 2021, 06:48 AM , By : samyak
How to solve implicit any type to index type error in typescript?
How to solve implicit any type to index type error in typescript?
like below fixes the issue How to solve this error , i would create custom type for presentToPast
TAG : typescript
Date : January 02 2021, 06:48 AM , By : tirullalleru
Unexpected let, use const instead
Unexpected let, use const instead
may help you . Function is a constructor, just like String,Array etc...Change it to
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Guilherme Maneskul
Variable 'x' is used before being assigned
Variable 'x' is used before being assigned
Hope that helps I got the following static method in the Logger class. I quite don't understand tsserver error. , You have
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Ryan Douglas
Access Typescript object property based on template argument
Access Typescript object property based on template argument
I think the issue was by ths following , You'll need to pass a value of type K in somewhere at runtime for this to work. If I understand the point of your Collection class properly, you will need both an actual array of T and a value of type K. A gre
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Nick Berry
Why did Typescript allow me to create an object without specifying required fields?
Why did Typescript allow me to create an object without specifying required fields?
should help you out You have to turn on --strictPropertyInitialization compiler option, then you will get errors highlighting uninitialized properties.
TAG : typescript
Date : January 02 2021, 06:48 AM , By : ABP123
How to format an array of dates using datepipe in angular?
How to format an array of dates using datepipe in angular?
This might help you import the DatePipe to your app.module file import { DatePipe} from '@angular/common'and format your date objects using this Pre-defined format options
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Claudia Legnani
Resolve 'Conflicting definitions for node' TS4090 error in VS 2017
Resolve 'Conflicting definitions for node' TS4090 error in VS 2017
help you fix your problem I have a TypeScript project that builds and runs, but I have a ton of build errors that all seem to stem from one error: , I fixed this by moving
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Osme Smile
Is it possible to have a function accept class instances, but not accept plain objects?
Is it possible to have a function accept class instances, but not accept plain objects?
around this issue Is it possible to have a function accept class instances, but not accept plain objects?
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Nihal
Extending a union type exactly
Extending a union type exactly
this one helps. A good solution won't exist unless this or this is implemented so just cast it.A extends Action doesn't allow A to be anything "larger" than Action. It cannot be Action | "DELETE". A extends B means that A is a subtype of B, or that i
TAG : typescript
Date : January 02 2021, 06:48 AM , By : anamarija
TypeScript function generic can only work for function overload with more than one signatures
TypeScript function generic can only work for function overload with more than one signatures
wish of those help I agree with Titian Cernicova-Dragomir that this seems like a compiler bug. The definition of IState basically states that the "send" property is a function which can be called with any types for "message", and the callback paramet
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Anh-Duc Le
Cannot find module that is defined in tsconfig `paths`
Cannot find module that is defined in tsconfig `paths`
To fix this issue I faced the same issue. I tried many things and now i got a solution which works for me. I have an app and a library in my angular project. I want to use a library alias in my app.I have following structure:
TAG : typescript
Date : January 02 2021, 06:48 AM , By : kang.ye
Why won't TS let me index into a compatible object type?
Why won't TS let me index into a compatible object type?
This might help you The compiler isn't as clever as you are, especially when it comes to reasoning about conditional types that depend on unresolved generic parameters (like NonSelected[P] extends string ? P : never). If you've gone over the logic an
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Arun Kumar
Can one represent indexable signatures in io-ts
Can one represent indexable signatures in io-ts
will help you As @aquz said, you're looking for t.record and you may find t.intersection helpful to get objects with required and additional/indexable properties.
TAG : typescript
Date : January 02 2021, 06:48 AM , By : FBtLL
Typescript allow extension of AxiosConfig
Typescript allow extension of AxiosConfig
I think the issue was by ths following , You have an interface that extends AxiosRequestConfig. And from the code image, it seems to me that you have added property silenceLoad: boolean.But here you have to understand, when you extend some interface,
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Jing Xu
How to match nested Keys in Typescript
How to match nested Keys in Typescript
I hope this helps . Directly? No. You can't create concatenate properties to create a new string in TS, which would be required for this functionality.However, you can get similar functionality with a mapped type.
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Sri Hari V
Enforce explicit function return type annotations?
Enforce explicit function return type annotations?
wish of those help No, Function return types are inferred in typescript. The compiler itself has no setting to turn off type inference on functions. This feature was requested and decline as discussed in this issue filed on the typescript repository.
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Manohar
winston custom transport with typescript
winston custom transport with typescript
this will help I'm having a hard time trying to get a winstom custom logger compiled using typescript. , When I replace your import statement with
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Devalur
Switching based on object type
Switching based on object type
I wish this helpful for you Your initial attempt is very close! The problem is that food instanceof String isn't quite right: that would work if FoodSet were (String | { value: string })[] (note the capital S).To check if food is a string, you should
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Mohamed Albakri
Typescript gives different errors in vscode than through webpack
Typescript gives different errors in vscode than through webpack
will help you I think you should check if you use the same TS version. Open command palette (ctrl+shift+p) type "Select Typescript version" and there you can verify if the bundled version matches your workspace version, you can also switch versions t
TAG : typescript
Date : January 02 2021, 06:48 AM , By : Eric Lowry
How to run TypeScript from local directory instead of global
How to run TypeScript from local directory instead of global
this will help You can add an entry to scripts in package.json to not only run tsc but fill in the standard arguments you want, e.g.:
TAG : typescript
Date : January 02 2021, 06:48 AM , By : ANeill
Why is typescript upset about comparing to undefined?
Why is typescript upset about comparing to undefined?
Does that help You've set up a trap for the next person to edit this code, who might think that writing
TAG : typescript
Date : January 02 2021, 06:48 AM , By : tr1ckster
Nested queries in Apollo Server
Nested queries in Apollo Server
help you fix your problem I am building a GraphQL schema using apollo-server. My schema has a large number of queries and I would like to group them together. Is there a way to group them by domain, so that I could make queries like: , Given a schema
TAG : typescript
Date : January 02 2021, 06:48 AM , By : kbmstkof
TypeScript dynamically derived fields from another type
TypeScript dynamically derived fields from another type
seems to work fine As of TypeScript 3.5 you cannot do this programmatically. There is an open issue in GitHub that suggests being able to augment keys in mapped types. If you care about this a lot, you might want to head over there and give it a or d
TAG : typescript
Date : January 02 2021, 06:48 AM , By : CL Mareydt
How can I create a generic type for a dynamic generated object created from an array
How can I create a generic type for a dynamic generated object created from an array
I think the issue was by ths following , I'm trying to generate a type definition for a function that generates an object from an array of props, but I'm having problems with this. , just a little bit workaround... here you are
TAG : typescript
Date : January 02 2021, 06:48 AM , By : E.Tiber
Typing declaration disambiguate Object or Function
Typing declaration disambiguate Object or Function
like below fixes the issue Everything is an Object in Javascript including functions. This is why the function matches the object overload.Overload order matters, and putting the function overload first will match the appropriate overload:
TAG : typescript
Date : January 02 2021, 06:48 AM , By : stephenbundi bundi

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