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Developing with WebStorm

For contributors using WebStorm as their preferred development environment, we recommend the following extensions to be installed:

We also recommend our contributors to enable TSLint in WebStorm to highlight and auto-fix linting problems directly in the editor. Make sure you are using the TSLint package from loopback-next loopback-next/packages/build/node_modules/tslint.

Please note that you should at least use WebStorm 2018.3 to avoid an indexing issue.

How to verify TypeScript setup

Compilation errors

  1. Open any existing TypeScript file, e.g. packages/src/index.ts

  2. Add a small bit of code to break TypeScript’s type checks, for example:

    const foo: number = 'bar';

  3. Verify that WebStorm editor has marked foo with a red underscore. Hover over foo and check the problem message. It should start with TS prefix followed by a message, e.g.

    TS2322: Type '"bar"' is not assignable to type 'number'.

  4. Check WebStorm Typescript Window. There should be an entry showing the same error. When you click on the entry, it should jump on the problematic line.

Verify that “Go to declaration” works across package boundaries. Find a place where we are calling @inject in authentication package, press Ctrl+B to go to the declaration of inject. WebStorm should jump to the .ts file in src (as opposed to jumping to a .d.ts file in dist)

Refactoring in WebStorm

It seems that refactorings like “rename” with (Maj+F6) will not change the renamed entity across packages.

How to verify ESLint setup

  1. Open any existing TypeScript file, e.g. packages/src/index.ts

  2. Verify that TSLint is not reporting any warnings : An example of a warning we want to avoid:

    Warning: The 'no-unused-variable' rule requires type information.

  3. Introduce two kinds linting problems - one that does and another that does not require type information to be detected. For example, you can add the following line at the end of the opened index.ts:

    const foo: any = 'bar';

  4. Verify that WebStorm editor has marked any with a red underscore. Hover over any and check the problem message. It should mention no-any rule, e.g.

    TSLint: Type declaration of 'any' loses type-safety. Consider replacing it with a more precise type. (no-any)