-
Notifications
You must be signed in to change notification settings - Fork 456
Commit
This commit does not belong to any branch on this repository, and may belong to a fork outside of the repository.
- Loading branch information
Showing
30 changed files
with
1,842 additions
and
74 deletions.
There are no files selected for viewing
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Some generated files are not rendered by default. Learn more about how customized files appear on GitHub.
Oops, something went wrong.
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| Original file line number | Diff line number | Diff line change |
|---|---|---|
| @@ -0,0 +1,76 @@ | ||
| --- | ||
| id: babel7-or-ts | ||
| title: Babel7 or TypeScript | ||
| --- | ||
|
|
||
| In Sept. 2018 Babel7 got released with an interesting preset: `@babel/preset-typescript`. | ||
|
|
||
| The goal is to make it easy for users using Babel to try TypeScript without moving out from Babel, just by adding a preset in their Babel config (here is the [MSDN blog post](https://blogs.msdn.microsoft.com/typescript/2018/08/27/typescript-and-babel-7/) about TypeScript and Babel 7). | ||
|
|
||
| ## Limitations | ||
|
|
||
| While `@babel/preset-typescript` is a great preset, you must know the limitation of it. Here is what is possible with TypeScript (and `ts-jest`), which is not with Babel7 and `@babel/preset-typescript`: | ||
|
|
||
| #### No type-checking | ||
|
|
||
| This is the big **PRO** of using TypeScript vs Babel, you have type-checking out of the box. | ||
|
|
||
| You'll get a more fluent TDD experience (when using `ts-jest`) since files will be type-checked at the same time they're compiled and ran. | ||
|
|
||
| Here TypeScript will throw while Babel won't: | ||
|
|
||
| ```ts | ||
| const str: string = 42 | ||
| ``` | ||
|
|
||
| With Babel, files are transpiled as isolated modules, there is no notion of "project". With TypeScript, files are part of a project and are compiled in that scope. | ||
|
|
||
| --- | ||
|
|
||
| #### No `namespace` | ||
|
|
||
| ```ts | ||
| namespace app { | ||
| export const VERSION = '1.0.0' | ||
| export class App { | ||
| /* ... */ | ||
| } | ||
| } | ||
| ``` | ||
|
|
||
| --- | ||
|
|
||
| #### No `const enum` | ||
|
|
||
| ```ts | ||
| const enum Directions { | ||
| Up, | ||
| Down, | ||
| Left, | ||
| Right, | ||
| } | ||
| ``` | ||
|
|
||
| --- | ||
|
|
||
| #### No declaration merging (`enum`, `namespace`, ...) | ||
|
|
||
| You won't be able to do [declaration merging](https://www.typescriptlang.org/docs/handbook/declaration-merging.html). | ||
|
|
||
| --- | ||
|
|
||
| #### No legacy `import`/`export` | ||
|
|
||
| ```ts | ||
| import lib = require('lib') | ||
| // ... | ||
| export = myVar | ||
| ``` | ||
|
|
||
| --- | ||
|
|
||
| #### No caret type-casting with JSX enabled | ||
|
|
||
| ```ts | ||
| const val = <string>input | ||
| ``` |
Oops, something went wrong.