https://www.usps.com/ - FAQ Information Missing

[OldMan77Webby]

My System: Windows 7 Professional 64-bit
Pale Moon version: V33.4.0.1 (2024-10-09) 64-bit
Adblock is disabled on the website:

Debug steps:

1. Go to USPS home page at: https://www.usps.com/
2. Scroll down to the bottom of the page under the first column, 4th entry.
3. Click on: FAQs.
4. No information is displayed on the webpage:

https://faq.usps.com/s/?_gl=1*fr2ghu*_g ... MC4wLjAuMA..

Toolkit Error Console Output Follows:

Code: Select all

Timestamp: 11/2/2024 12:38:27 PM
Error: XML Parsing Error: syntax error
Location: https://p.tvpixel.com/com.snowplowanalytics.snowplow/tp2
Line Number 1, Column 1:
Source File: https://p.tvpixel.com/com.snowplowanalytics.snowplow/tp2
Line: 1, Column: 1
Source Code:
ok

Timestamp: 11/2/2024 12:38:43 PM
Error: ReferenceError: TransformStream is not defined
Source File: https://faq.usps.com/s/sfsites/auraFW/javascript/ZzhjQmRxMXdrdzhvS0RJMG5qQVdxQTdEcXI0cnRHWU0zd2xrUnFaakQxNXc5LjMyMC4y/aura_prod.js line 321 > eval
Line: 1

The FAQ works in Firefox browser.

[Moonchild]

The issue is "TransformStream"
Not entirely sure why a FAQ page would be using arbitrary data transformation on the browser side, but it's part of the Streams API we don't support at the moment.

[vannilla]

The issue is "TransformStream"
Not entirely sure why a FAQ page would be using arbitrary data transformation on the browser side, but it's part of the Streams API we don't support at the moment.

After having to dabble with some minimal frameworks due to certain obligations, I think I have a suspect: most development environments use tools that catenate javascript files together and then apply some tranformations (e.g. minimization) to this catenation. It's very likely that a specific page or widget allocates one of these classes at the top level (a global variable, a "static" class property, etc.) and because this piece of code is always made available due to file joins, even a FAQ will end up requiring it.
Of course bad tooling does not exclude bad programming: why is the site even using the Stream API in the first place? Still, it is something that can cause issues even in "properly" coded sites.
It might also be a way to detect features, but crashing completely with no fallbacks or a structured error message makes it extremely unlikely.

[adoxa]

Here's a Modify HTTP Response filter to work around it (currently only for the FAQ URL, so other pages may still be broken).

Code: Select all

[["faq.usps.com",["/app\\.js/",["/extends TransformStream(.*?)super.*?\\}\\)/","$1"]]]]