Problem

gateway/platforms/helpers.py contains the same overly-greedy Markdown underscore regex that was already fixed in cli.py. The TextBatchAggregator class uses _RE_ITALIC_UNDER = re.compile(r"_(.+?)_", re.DOTALL) which strips underscores from alphanumeric identifiers like send_as_bot, user_id, my_variable.

Root Cause

Lines 160-161 in gateway/platforms/helpers.py:

# Old (buggy) — matches ANY underscore pair greedily
_RE_BOLD_UNDER = re.compile(r"__(.+?)__", re.DOTALL)
_RE_ITALIC_UNDER = re.compile(r"_(.+?)_", re.DOTALL)

This is identical to the bug that was fixed in cli.py's _strip_markdown_syntax() — but the helpers.py copy was missed.

Fix

Replace with lookbehind/lookahead assertions that only match actual Markdown italic delimiters:

# New (fixed) — requires non-alphanumeric boundaries on both sides
_RE_BOLD_UNDER = re.compile(r'(?<![a-zA-Z0-9])__(?=[^\s])(.+?)(?<=[^_])__(?![a-zA-Z0-9])', re.DOTALL)
_RE_ITALIC_UNDER = re.compile(r'(?<![a-zA-Z0-9])_(?=[^\s])(.+?)(?<=[^_])_(?![a-zA-Z0-9])', re.DOTALL)

Impact

• Identifiers like send_as_bot, user_id, my_variable are no longer corrupted when text is stripped via TextBatchAggregator
• Actual Markdown italic _text_ still correctly stripped
• Consistent with the fix already applied to cli.py

Type of Change

• Bug fix (non-breaking change that fixes an issue)

Changes Made

• gateway/platforms/helpers.py: Fixed _RE_BOLD_UNDER and _RE_ITALIC_UNDER regex patterns (2 lines changed)

How to Test

1. Send a message containing send_as_bot or user_id through any gateway platform
2. Verify the identifiers are preserved in the output text
3. Verify actual Markdown italic _text_ is still correctly stripped