Warn on older versions of func

[gauron99]

This is a subsequent PR to #2

• warn on func version when version is <= 3 than latest (latest - 3 and older)
• one "practical" test in workflow for simplicity (can check manually in the workflow which uses custom version)

please note

• when someone specifies the custom binary url base we skip the version check (dont warn)
• when someone specifies 'latest' version we skip the version check (dont warn)

will add in subsequent PR

• some js tests to cover this ( I want to remove the node_modules first -- use ncc module )

[twoGiants]

Good job! 👍

I think we can make it a bit simpler. Wdyt?

See my comments below.

[twoGiants]

This is a big change for a small thing => the warning.

I would propose to revert most changes and put a small logic change right after const version = smartVersionUpdate(versionInput); in line 105.

[twoGiants]

const version = smartVersionUpdate(versionInput);
warnStaleVersion(version);

I would put the core.info(Using specific version ${version}); in the warnStaleVersion and log it if the version is fine.

[twoGiants]

This can be done a bit simpler using the github redirect to the latest version. No need for JSON etc.:

async function getLatestVersion() {
    const response = await fetch('https://github.com/knative/func/releases/latest', {
        method: 'HEAD',
        redirect: 'manual'
    });
    
    const location = response.headers.get('location');
    // location: "https://github.com/knative/func/releases/tag/knative-v1.21.0"
    return location.split('/').pop(); // "knative-v1.21.0"
}

Then you can use this function to get the version here:

async function warnStaleVersion(version) {
    let latestVersion;
    try {
        latestVersion = getLatestVersion()
    } catch (error) {
        core.debug(`Failed fetching latest version: ${error.message}`);
        return;
    }

    const offset = 3;
    if (hasVersionDrift(latestVersion, version, offset)) {
        core.warning(
            `You are using func ${version}, which is ${offset} versions behind the latest (${latestVersion}). Upgrading is recommended.`
        );
        return;
    }

    core.info(`Using specific version ${version}`);
}

versionDiff has a bug. I would not write a warning in this case of version = 1.0.0 and latestVersion = 2.0.0.

I would change versionDiff to hasVersionDrift and change the implementation to use major and minor versions for checking, e.g. knative-v1.21.0 becomes 121 and knative-v1.18.0 becomes 118 and then you subtract them and compare the abs(121 - 118) to offset.

It looks like the time is coming closer for unit tests for this action 😆 .

[gauron99]

Well, the comment does say its a "difference of minor versions" 😄 but i get your point. I didnt take it would be needed any time soon. Will update it. The redirect location is super cool! will update that.

[twoGiants]

the comment does say its a "difference of minor versions" 😄

You're right of course. My thinking was that if someone adds a very old version for some reason or in future when we have v2+. But you got it 😸 👍