fix(telegram): use UTF-16 code units for message length splitting - #8725
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Port from nearai/ironclaw#2304: Telegram's 4096 character limit is measured in UTF-16 code units, not Unicode codepoints. Characters outside the Basic Multilingual Plane (emoji like 😀, CJK Extension B, musical symbols) are surrogate pairs: 1 Python char but 2 UTF-16 units. Previously, truncate_message() used Python's len() which counts codepoints. This could produce chunks exceeding Telegram's actual limit when messages contain many astral-plane characters. Changes: - Add utf16_len() helper and _prefix_within_utf16_limit() for UTF-16-aware string measurement and truncation - Add _custom_unit_to_cp() binary-search helper that maps a custom-unit budget to the largest safe codepoint slice position - Update truncate_message() to accept optional len_fn parameter - Telegram adapter now passes len_fn=utf16_len when splitting messages - Fix fallback truncation in Telegram error handler to use _prefix_within_utf16_limit instead of codepoint slicing - Update send_message_tool.py to use utf16_len for Telegram platform - Add comprehensive tests: utf16_len, _prefix_within_utf16_limit, truncate_message with len_fn (emoji splitting, content preservation, code block handling) - Update mock lambdas in reply_mode tests to accept **kw for len_fn
lauchiwa
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Apr 17, 2026
…usResearch#8725) Port from nearai/ironclaw#2304: Telegram's 4096 character limit is measured in UTF-16 code units, not Unicode codepoints. Characters outside the Basic Multilingual Plane (emoji like 😀, CJK Extension B, musical symbols) are surrogate pairs: 1 Python char but 2 UTF-16 units. Previously, truncate_message() used Python's len() which counts codepoints. This could produce chunks exceeding Telegram's actual limit when messages contain many astral-plane characters. Changes: - Add utf16_len() helper and _prefix_within_utf16_limit() for UTF-16-aware string measurement and truncation - Add _custom_unit_to_cp() binary-search helper that maps a custom-unit budget to the largest safe codepoint slice position - Update truncate_message() to accept optional len_fn parameter - Telegram adapter now passes len_fn=utf16_len when splitting messages - Fix fallback truncation in Telegram error handler to use _prefix_within_utf16_limit instead of codepoint slicing - Update send_message_tool.py to use utf16_len for Telegram platform - Add comprehensive tests: utf16_len, _prefix_within_utf16_limit, truncate_message with len_fn (emoji splitting, content preservation, code block handling) - Update mock lambdas in reply_mode tests to accept **kw for len_fn (cherry picked from commit 9e992df)
aj-nt
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May 1, 2026
…usResearch#8725) Port from nearai/ironclaw#2304: Telegram's 4096 character limit is measured in UTF-16 code units, not Unicode codepoints. Characters outside the Basic Multilingual Plane (emoji like 😀, CJK Extension B, musical symbols) are surrogate pairs: 1 Python char but 2 UTF-16 units. Previously, truncate_message() used Python's len() which counts codepoints. This could produce chunks exceeding Telegram's actual limit when messages contain many astral-plane characters. Changes: - Add utf16_len() helper and _prefix_within_utf16_limit() for UTF-16-aware string measurement and truncation - Add _custom_unit_to_cp() binary-search helper that maps a custom-unit budget to the largest safe codepoint slice position - Update truncate_message() to accept optional len_fn parameter - Telegram adapter now passes len_fn=utf16_len when splitting messages - Fix fallback truncation in Telegram error handler to use _prefix_within_utf16_limit instead of codepoint slicing - Update send_message_tool.py to use utf16_len for Telegram platform - Add comprehensive tests: utf16_len, _prefix_within_utf16_limit, truncate_message with len_fn (emoji splitting, content preservation, code block handling) - Update mock lambdas in reply_mode tests to accept **kw for len_fn
02356abc
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May 14, 2026
…usResearch#8725) Port from nearai/ironclaw#2304: Telegram's 4096 character limit is measured in UTF-16 code units, not Unicode codepoints. Characters outside the Basic Multilingual Plane (emoji like 😀, CJK Extension B, musical symbols) are surrogate pairs: 1 Python char but 2 UTF-16 units. Previously, truncate_message() used Python's len() which counts codepoints. This could produce chunks exceeding Telegram's actual limit when messages contain many astral-plane characters. Changes: - Add utf16_len() helper and _prefix_within_utf16_limit() for UTF-16-aware string measurement and truncation - Add _custom_unit_to_cp() binary-search helper that maps a custom-unit budget to the largest safe codepoint slice position - Update truncate_message() to accept optional len_fn parameter - Telegram adapter now passes len_fn=utf16_len when splitting messages - Fix fallback truncation in Telegram error handler to use _prefix_within_utf16_limit instead of codepoint slicing - Update send_message_tool.py to use utf16_len for Telegram platform - Add comprehensive tests: utf16_len, _prefix_within_utf16_limit, truncate_message with len_fn (emoji splitting, content preservation, code block handling) - Update mock lambdas in reply_mode tests to accept **kw for len_fn
waefrebeorn
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Jul 2, 2026
…usResearch#8725) Port from nearai/ironclaw#2304: Telegram's 4096 character limit is measured in UTF-16 code units, not Unicode codepoints. Characters outside the Basic Multilingual Plane (emoji like 😀, CJK Extension B, musical symbols) are surrogate pairs: 1 Python char but 2 UTF-16 units. Previously, truncate_message() used Python's len() which counts codepoints. This could produce chunks exceeding Telegram's actual limit when messages contain many astral-plane characters. Changes: - Add utf16_len() helper and _prefix_within_utf16_limit() for UTF-16-aware string measurement and truncation - Add _custom_unit_to_cp() binary-search helper that maps a custom-unit budget to the largest safe codepoint slice position - Update truncate_message() to accept optional len_fn parameter - Telegram adapter now passes len_fn=utf16_len when splitting messages - Fix fallback truncation in Telegram error handler to use _prefix_within_utf16_limit instead of codepoint slicing - Update send_message_tool.py to use utf16_len for Telegram platform - Add comprehensive tests: utf16_len, _prefix_within_utf16_limit, truncate_message with len_fn (emoji splitting, content preservation, code block handling) - Update mock lambdas in reply_mode tests to accept **kw for len_fn
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Summary
Port from nearai/ironclaw#2304: Telegram's 4096 message length limit is measured in UTF-16 code units, not Unicode codepoints. Astral-plane characters (emoji, CJK Extension B, musical symbols) are surrogate pairs — 1 Python char but 2 UTF-16 units. Messages heavy on emoji could silently exceed the limit.
Changes:
utf16_len(),_prefix_within_utf16_limit(),_custom_unit_to_cp()helpers in base.pytruncate_message()now accepts optionallen_fnparameterlen_fn=utf16_lenfor splittingsend_message_tool.pyalso usesutf16_lenfor Telegram**kwsignature changeTests
124 tests pass (test_platform_base.py + test_discord_reply_mode.py + test_telegram_reply_mode.py)
Closes #8698