Change export of check function to an object

[dotjay]

Triage

Type of change

Please select any of the below items that are appropriate.

This pull request:

• Adds a new carbon estimation model to CO2.js
• Adds new functionality to an existing model
• Fixes a bug with an existing model implementation
• Add other new functionality to CO2.js
• Add new data to CO2.js
• Improves developer experience for contributors
• Adds contributors to CO2.js
• Does something not specified above

Related issue/s

• Green hosting.check() method implementation inconsistent between Node CommonJS and ESM #266

Docs changes required

Do any changes made in this pull request require parts of the CO2.js documentation to be updated?

• Yes
• No
• I don't know

Describe the changes made in this pull request

Make check() a public method for the ESM version by wrapping the exported method in an object, making more consistent with the CJS version.

[fershad]

Thanks @dotjay

When I test out this code on the following, it throws an error (TypeError: hosting is not a function):

const { hosting } = require("@tgwf/co2");

const options = {
  verbose: false,
  userAgentIdentifier: "myGreenApp",
};
hosting("google.com", options).then((result) => {
  console.log(result);
});

I'm wondering if something is happening in the build step that messes with this.

[dotjay]

I'll try to explain more clearly…

This CommonJS script works. It calls hosting.check()…

#!/usr/bin/env node

const { co2, hosting } = require("@tgwf/co2");

const bytes = 100000;
const url = "https://digitalasitshouldbe.com/";

async function main() {
    const co2Model = new co2({ model: "swd", version: 4, rating: true });
    const co2Data = co2Model.perByte(bytes);

    const hostDomain = new URL(url).hostname;
    const isGreenHosted = await hosting.check(hostDomain, { verbose: true });

    console.log(co2Data);
    console.log(isGreenHosted);
}

main();

If I try to run the same code, but as a module:

#!/usr/bin/env node

import { co2, hosting } from "@tgwf/co2";

const bytes = 100000;
const url = "https://digitalasitshouldbe.com/";

async function main() {
    const co2Model = new co2({ model: "swd", version: 4, rating: true });
    const co2Data = co2Model.perByte(bytes);

    const hostDomain = new URL(url).hostname;
    const isGreenHosted = await hosting.check(hostDomain, { verbose: true });

    console.log(co2Data);
    console.log(isGreenHosted);
}

main();

… Node throws an error: TypeError: hosting.check is not a function

This is why I flagged an issue of consistency with the code example in the tutorial in Issue #266. With the ES Module version of the hosting object, the check() method itself is exported rather than an object containing check. I have to change the line in my module code for it to work:

// Note: hosting.check() isn't there in ESM version; use hosting()
const isGreenHosted = await hosting(hostDomain, { verbose: true });

[fershad]

@dotjay if you're using v0.17 you can use:

const { check } = require("@tgwf/co2/hosting");
import { check } from "@tgwf/co2/hosting";

So your code examples would become:

CJS:

#!/usr/bin/env node

- const { co2, hosting } = require("@tgwf/co2");
+ const { co2 } = require("@tgwf/co2");
+ const { check } = require("@tgwf/co2/hosting");

const bytes = 100000;
const url = "https://digitalasitshouldbe.com/";

async function main() {
    const co2Model = new co2({ model: "swd", version: 4, rating: true });
    const co2Data = co2Model.perByte(bytes);

    const hostDomain = new URL(url).hostname;
-    const isGreenHosted = await hosting.check(hostDomain, { verbose: true });
+    const isGreenHosted = await check(hostDomain, { verbose: true });

    console.log(co2Data);
    console.log(isGreenHosted);
}

main();

ESM:

#!/usr/bin/env node

- import { co2, hosting } from "@tgwf/co2";
+ import { co2 } from "@tgwf/co2";
+ import { check } from "@tgwf/co2/hosting";

const bytes = 100000;
const url = "https://digitalasitshouldbe.com/";

async function main() {
    const co2Model = new co2({ model: "swd", version: 4, rating: true });
    const co2Data = co2Model.perByte(bytes);

    const hostDomain = new URL(url).hostname;
-    const isGreenHosted = await hosting.check(hostDomain, { verbose: true });
+    const isGreenHosted = await check(hostDomain, { verbose: true });
 
    console.log(co2Data);
    console.log(isGreenHosted);
}

main();

[dotjay]

That's okay, except I'd argue that it's not an approach I'd expect as a Node developer, i.e. having to import twice from a package, once from a subordinate class.