[Themes] - Improve storefront password detection for password-protected shops with redirects

[jamesmengo]

WHY are these changes introduced?

Closes https://github.com/Shopify/develop-advanced-edits/issues/444

Fixes an issue with password protection detection in storefronts by improving the URL validation approach.

If you shop has a redirect, the path is as follows:

• test.myshopify.com -> test.redirected.com -> test.redirect.com/password

Also, some domains return a 301 rather than a 302.

In the long run, this should be moved to an API call to make this more robust - that's not currently possible.

WHAT is this pull request doing?

Updates the storefront password protection check to use the final URL from the response instead of checking redirect headers.

This simplifies the logic and handles both direct and redirect cases uniformly.

How to test your changes?

1. Set up a password-protected development store with a redirected URL
2. Run theme dev on that store
3. Verify that you are getting prompted to enter your password - opening the localhost should render your home-page, not the password page
4. Inputting your password correctly should allow you to skip the password page when you open the local-host preview.

🎥 Video uploaded on Graphite:

Measuring impact

• n/a - this doesn't need measurement, e.g. a linting rule or a bug-fix

Checklist

• I've considered possible cross-platform impacts (Mac, Linux, Windows)
• I've considered possible documentation changes

[jamesmengo]

• [Themes] - Improve storefront password detection for password-protected shops with redirects #4936 👈 (View in Graphite)
• main

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Coverage report

St.❔	Category	Percentage	Covered / Total
🟡	Statements	75.24% (-0.1% 🔻)	8651/11498
🟡	Branches	70.6% (-0.08% 🔻)	4222/5980
🟡	Functions	74.83% (-0.14% 🔻)	2268/3031
🟡	Lines	75.81% (-0.1% 🔻)	8183/10794

Show files with reduced coverage 🔻

St.❔	File	Statements	Branches	Functions	Lines
🟢	... / app.test-data.ts	92.51%	93.4% (-0.24% 🔻)	83.75%	92%
🟢	... / specification.ts	88.89% (-0.66% 🔻)	86.36% (-0.59% 🔻)	88% (-0.46% 🔻)	87.27% (-0.66% 🔻)
🟢	... / ui_extension.ts	97.5% (-0.58% 🔻)	83.33% (-3.33% 🔻)	100%	97.44% (-0.64% 🔻)
🟢	... / app-event-watcher.ts	93.42% (-1.52% 🔻)	87.88% (-0.69% 🔻)	90.48%	98.53% (-0.06% 🔻)
🟢	... / app-watcher-esbuild.ts	88.89% (-4.44% 🔻)	87.5% (-2.5% 🔻)	86.67% (-3.33% 🔻)	93.94% (-3.56% 🔻)
🟢	... / file-watcher.ts	80.22% (-4.47% 🔻)	69.77% (-0.69% 🔻)	79.17% (-8.83% 🔻)	85% (-4.53% 🔻)
🟡	... / common.ts	80%	62.5% (-7.5% 🔻)	71.43%	78.95%
🟢	... / ConcurrentOutput.tsx	98.36% (-1.64% 🔻)	88% (-4% 🔻)	100%	98.33% (-1.67% 🔻)

Test suite run success

1958 tests passing in 888 suites.

Report generated by 🧪jest coverage report action from 115718c