Web3 typescript definition has no default export

[nicolaslawdune]

Hello,

Web3 Typescript definition on branch 1.0 doesn't contain "default export".

Context

• Typescript version : 2.6.2
• Converting ES2015(ES6) to ES5

After importing :
import Web3 from 'web3';

Compilation Error

Module '"xxxx/node_modules/web3/index"' has no default export.

Update 1

After importing like this import Web3 = require('web3'); I got a compilation error :

error TS1202: Import assignment cannot be used when targeting ECMAScript modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from
"mod"', or another module format instead.

This error is due to Module mode from tsconfig which is ES6.

Update 2

I remove module mode from tsconfig and it works now.

[matrushka]

Have you seen #1184 ?

[connectdotz]

the type definition reflects the current module implementation line 78

module.exports = Web3;

Based on typescript document, it is recommended to adopt module-class, which is why the type is exposed with "=" and not default.

We have been going back and forth on this issue as you can see with #1184, which was exactly to undo the default import that undo the "=" earlier... I am sure we don't want to keep repeating this cycle, will the following import syntax work for you?

import Web3 = require("web3")

[nicolaslawdune]

Using "require" keyword, I got this error on compilation (module: ES6 and target: ES5)

error TS1202: Import assignment cannot be used when targeting ECMAScript modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from
"mod"', or another module format instead.

[connectdotz]

web3.js is still using es5 module system, so it's best to use the compiler option that supports it... try module: "commonjs"

[kespeart]

Doing import Web3 from 'web3' works for me in version 1.0.0-beta.26 but when i upgrade to 1.0.0-beta.27 I receive the error mentioned in this post.

I could use the lower version but i noticed that the method for viewing pass events, which is what i want to do, has changed in .27. In version *.26 the passed events can be viewed by invoking getPastLogs(*) but in *.27 you have to call getPastEvents(*);

Please resolve soon, thanks

[kespeart]

seems like @nicolaslawdune has a PR for this

[connectdotz]

here is the bottom line:

• export = works for module:"commonjs" but breaks module:"es6"
• export default works for module:"es6" but breaks module:"commonjs"

If you guys look at the commit history, you can see that we have tried both export styles multiple times because every time you switch to one the other camp complained. Giving the module can't be exported both "=" and "default", we have to choose one...

but which one? I think we all agree that the type definition should closely reflect the original package implementation: current web3's js implementation uses "export =", according to typescript official doc, it is recommended to adopt type definition with "export =" (see here). This tips the scale for export =.

[hodlbank]

PR1249 made it "export default" again in version 1.0.0-beta.30 . Doesn't work with commonjs anymore.

[macbem]

Just use ES Modules since it's JavaScript's official module system and stop changing it all the time. It's a breaking change and breaking changes are never welcome.

[AlexBeauchemin]

What I ended up doing to stop typescript from complaining and still have type definition and autocompletion is

import * as W3 from 'web3';
const Web3 = require('web3'); // tslint:disable-line

const web3: W3.default = new Web3(new Web3.providers.HttpProvider('http://localhost:8545'));
const balance = await web3.eth.getBalance('0x...');
...

[rraina]

@AlexBeauchemin was able to make it work as follows:

import W3 from 'web3';

export const network = 'XXX';
export const web3: W3 = new W3(new W3.providers.HttpProvider(network));