Best solution for transpiling Typescript into ES6 without transpiling of Async?

Question

sorry the title perhaps makes you confused, let me explain of it:

our JS environment is a little bit special, fully ES6 support without native generator function* and yield, so the Typescript code:

async test(): Promise {
    return await Promise.resolve();
}

will be Transpiled into ES6:

function test() {
    return __awaiter(this, void 0, void 0, function* () { return yield Promise.resolve(); });
}

but, wryly... our env does not support native generator.. and, also we can't transpile TS into ES5, because there a few of libs referenced by the proj are ES6 modules, so if you transpile TS into ES5, the class can't be inherited (ES5 uses __extends to do this)

so I'm finding a solution to transpile our TS codes into ES6 but with all async in it transpiled into ES5 like style (tslib.js)

I can accept whatever solutions, npm / node / post scripts / TS features whatever, what I need is clues! thanks guys.

Answer 1

Thanks to @ecraig12345 for the tips.

Actually to achieve this, you have to use Babel plugin to transpile the JS generated from TS source again.

The steps:

1, normally compile and output JS files from your TS project.

2, use npm to install Babel and related plugins:

@babel/cli

@babel/core

@babel/runtime

@babel/plugin-transform-for-of

@babel/plugin-transform-regenerator

@babel/plugin-transform-runtime

3, edit your .babelrc file and use this content: { "plugins": [ "@babel/plugin-transform-for-of", "@babel/plugin-transform-regenerator", "@babel/plugin-transform-runtime" ] }

4, edit your tasks.json of your TS project: { .... "tasks": [ { "label": "deployTs", "group": "build", "type": "shell", "command": "tsc TS_OUTPUT_JS_FOLDER/ --module commonjs --target es6" }, { "label": "deployFinal", "group": "build", "type": "shell", "command": "npx babel TS_OUTPUT_JS_FOLDER/ -d RE_TRANSPILE_OUTPUT_FOLDER/", "dependsOn": ["depolyTs"], "dependsOrder": "sequence" }, .... ] .... }

5, and then just execute deployFinal task by menu Terminal > Run Tasks, and the task will first compile TS and then run Babel to transpile async syntax in the output folder step by step.

Have fun.