Enable/Disable Single-page app routing

[mikemurray]

Resolves #417
Impact: minor
Type: feature

Issue

Description of the issue this PR is solving, why it's happening, and how to reproduce it. This may differ from the original ticket as you now have more information at your disposal.

Solution

• Add an .env var to enable SPA routing
• Extend next-routes to allow for full page loads
• Update the link component to allow for full page loads
• Update PDP to force it into single-page app mode for variant selection
• Update RoutingStore to for it into single-page app mode when updating the search query (used for the grid filtering)

Breaking changes

ENABLE_SPA_LINKS=true should be placed in your .env file

Testing

With ENABLE_SPA_LINKS=true

1. Click through the app and make sure everything works
2. Check the network panel and verify that the page isn't reloaded. (shouldn't see a request for an HTML page)

With ENABLE_SPA_LINKS=false

1. Click through the app and make sure everything works
2. Check the network panel and verify that a request for the full page is made
3. Ensure the PDP variant selection does not force a full page load
4. Ensure that the grid filter controls do not force a full page load

[impactmass]

@mikemurray thinking about the new ENABLE_SPA_LINKS env; should it have a default value true? since that's the previous SPA behaviour. That way if that ENV is not set, it has the default behaviour

[mikemurray]

@impactmass then maybe DISABLE_SPA_LINKS=true would be better. that way if that doesn't exist, then the default behavior will continue.

[mikemurray]

@impactmass I ended up leaving the .env var the same name and ensuring that the SPA routing is enabled by default.

I also fixed the prop-type warning you were seeing.

Now on to fixing the broken tests.

[mikemurray]

@impactmass ready for review

[impactmass]

Tested and the full pages loads as described when enabled.

I have a note about the env setup. It feels like a global project concern, but wanted to point it out

[mikemurray]

@impactmass updated the logic and added a comment. Ready for review again.

[impactmass]

Approving.

It would be good to revisit the env setup later.