[ARROW-9496] [JS] toArray() called on filtered Table returns all rows

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Won't Fix
• Component/s: JavaScript
• Environment: OSX 10.15.2 ; Behavior seen in browser and node
• External issue URL: https://github.com/apache/arrow/issues/25566
• Assignee: Unassigned
• Reporter: Peter Murphy
• Created: 15/Jul/20 23:18
• Updated: 11/Jan/23 08:07
• Resolved: 17/Jan/22 02:58

Description

Trying to experiment with building a library on top of Apache Arrow's Javascript implementation, but ran into this:

Example:
https://runkit.com/pjm17971/pond-arrow

const filtered = table.filter(predicate.col("pressure").lt(28.5))
filtered.count() // 2 (correct)

 However:

const result = filtered.toArray().map(row => row.toJSON()) // 4 rows (??)

Is this expected behavior?