Add code fix to convert 'require' in a '.ts' file to an 'import'

[ghost]

In TypeScript code, a require() call gives you any even in --noImplicitAny mode. Top-level requires can be converted to import = statements, or default imports if --allowSyntheticDefaultImports is enabled.

[mhegazy]

sometimes you do that to avoid making your file a module.. we should check that the file is already a module before offering this suggestion, otherwise more errors would be produced.

[mhegazy]

i take back my original comment. we should just do this all the time. with this check enabled a simple scenario like #23780 would not trigger the suggestion..

[mhegazy]

sorry about flip-flopping on this issue.

[WangPengJu]

just like you say "sometimes you do that to avoid making your file a module". @mhegazy
a.ts

import fs = require("fs");
namespace G {
    export let a = 0;
}

b.ts

G.a // error 

I want use namespace as global. not single module. but if use "import fs = require('fs')" in "a.ts", "b.ts" can't use G. if use "const fs = require("fs")", it's work.

"const fs = require("fs")" no intellisense in vscode, webstorm have intellisense. it's confuse me.

[ghost]

@WangPengJu require is just a function any => any -- webstorm must have a separate layer on top of TypeScript. I don't think there's any way to create a global namespace inside a module scope -- even in a commonjs system, a var in a module is still local, and that's what a namespace compiles to.

[WangPengJu]

finally, i will merger all file in one file(as global). so that is why i use namespace. not module. @Andy-MS

[WangPengJu]

const fs: typeof import ("fs") = require("fs");

it's work.
use typescript: 2.9.0-dev.20180501