1460805 - BinAST error during FB newsfeed load: "TypeError: BinAST Error: Captured variable was not declared as captured"

Status: RESOLVED FIXED

(Core :: JavaScript Engine, defect)

Description

[Vladan Djeric (:vladan)]

Attachment: Stack that throws error (streaming parsing)

This is a BinAST error encountered during FB newsfeed load. It is not from my usual fb_bench newsfeed snapshot.

See attached error stack (not super interesting).

I attached a minimal test case. To test it:

1. Clone https://github.com/vdjeric/binast-server
2. Put the test case in the same binast-server/ directory
3. ./serveBinAST.py .
4. Load https://localhost:8443/browserlab.htm

Comment 1

[Vladan Djeric (:vladan)]

Attachment: Test case, trivial html file

Comment 2

[Vladan Djeric (:vladan)]

Attachment: HTML file for test case

Comment 3

[Vladan Djeric (:vladan)]

Attachment: BinAST file for test case

Comment 4

[Vladan Djeric (:vladan)]

Attachment: Plain JS file for test case (download all 3)

Comment 5

[Vladan Djeric (:vladan)]

Jonco: why doesn't the BinAST error bubble up to the DevTools console? I only got "Loading failed for the <script> with source <url>"

Comment 6

[Eric Faust [:efaust]]

BinAST error is on the encoder side. Will fix and PR appropriately. Nothing more needs to be done for SM.

Comment 7

[David Teller [:Yoric] - still alive but not very active]

Yeah, definitely looks like an encoder error. If you have a PR, I'll merge it immediately.

Comment 8

[David Teller [:Yoric] - still alive but not very active]

Normally, efaust has fixed this with https://github.com/binast/binjs-ref/pull/127 .