You can now simply npm install –save-dev ts-node nodemon and then run nodemon with a .ts file and it will Just Work: nodemon app.ts Previous versions: I was struggling with the same thing for my development environment until I noticed that nodemon‘s API allows us to change its default behaviour in order to execute a … Read more
You could use a generic parameter default and a type assertion to tell the compiler that a lack of inference for A implies that A is Lion, and that it’s okay to make that assumption: function createInstanceAssert<A extends Animal = Lion>(c: new () => A = Lion as any) { return new c(); } This … Read more
If you want something that works from both the caller’s point of view and from the implementer’s point of view, you can do this: function shouldOnlyAcceptStringValues<K extends PropertyKey>( o: Record<K, string>, key: K ) { const okay: string = o[key]; } This is sort of looking at your constraint backwards; instead of constraining key to … Read more
It’s by design. In short, Typescript creators made it this way because they know Javascript is a very dynamic language with many such use cases. You should read this carefully: https://www.typescriptlang.org/docs/handbook/interfaces.html#excess-property-checks (however I bet the question arised from reading it). Object literals get special treatment Their logic might be like this: if you have a … Read more
In Typescript 2.8 you can explicitly eliminate the modifier: type Foo2 = { [P in keyof Foo]-?: number; } Or use the Required type that is built into newer versions. If you are using an older version you can use this workaround: type Helper<T, TNames extends string> = { [P in TNames]: (T & { … Read more
Both approaches are valid. If your function uses conditional types in the return it will need to use type assertions, as typescript will not try to reason about the conditional type since it contains a free type parameter: function dependsOnParameter<B extends boolean>(x: B): B extends true ? number : string { if (x) { return … Read more
Hope this helps, this will cause it to fail. The underlying cause here is Typescripts reliance on structural typing which is alot better than the alternative which is Nominal typing but still has its problems. type StrictPropertyCheck<T, TExpected, TError> = Exclude<keyof T, keyof TExpected> extends never ? {} : TError; interface Animal { speciesName: string … Read more
It’s a bit buried in the documentation, but if you add some things to the ‘extends’ property, you can use both the rules recommended by ESLint like no-unused-vars, and have it actually work in Typescript. Like so: “extends”: [ “eslint:recommended”, “plugin:@typescript-eslint/eslint-recommended”, “plugin:@typescript-eslint/recommended” ], @typescript-eslint/recommended seems to be the thing that allows eslint:recommended to deal with … Read more
As far as I know, Angular is only updating the view, if you change data in the “Angular zone”. The asynchronous call in your example does not qualify for this. But if you want, you can put it in the Angular zone or use rxjs or extract part of the code to a new component … Read more
So after reading your comment, I realized I misunderstood your question! If you want to control the paths from an imported package’s perspective, just use set the main property of your package.json to a file that properly represents the object graph of your module. { “main”: “common-utils/dist/es2015/index.js” } If you’re attempting to control the import … Read more