Fix JSON-RPC response validation

[JunichiSugiura]

Description

Fixed the send method on Web3EthereumProvider to return response result, not response object itself otherwise GetAccountsMethod.js#L47 throws an error.

Type of change

• Bug fix
• New feature
• Breaking change
• Enhancement

Checklist:

• I have selected the correct base branch.
• I have performed a self-review of my own code.
• I have commented my code, particularly in hard-to-understand areas.
• I have made corresponding changes to the documentation.
• My changes generate no warnings.
• I have updated or added types for all modules I've changed
• Any dependent changes have been merged and published in downstream modules.
• I ran npm run test in the root folder with success and extended the tests if necessary.
• I ran npm run build in the root folder and tested it in the browser and with node.
• I ran npm run dtslint in the root folder and tested that all my types are correct
• I have tested my code on an ethereum test network.

[coveralls]

Coverage decreased (-0.003%) to 95.862% when pulling 7929596 on LukeSugiura:hotfix/eip1193-provider-result into caa9410 on ethereum:1.0.

[JunichiSugiura]

I’ve been reading through the API described in EIP1193 and become skeptical about my fix above. The example showed here seems like the provider’s send method only returns the JSON-RPC response result.

In this case, the current return value from Web3EthereumProvider.send method seems right but the validation method needs to be changed to something like below.

// Web3EthereumProvider.js
...
async send (method, parameters) {
    let response;
    try {
        response = await this.connection.send(method, parameters);
    } catch (error) {
        throw new Error(`Node error: ${error.message}`);
    }

    if (response === undefined) {
        throw new Error(`Validation error: Undefined JSON-RPC result`);
    }

    return response;
}
...

@nivida Could you verify this approach, please?

[nivida]

This check isn't required :)

[JunichiSugiura]

fix: 747554b

[JunichiSugiura]

@nivida Undefined check is now removed!