fix: use removeprefix and fix remaining underscore-prefix serialization paths

[ktrufanov-skycop]

Summary

Follow-up to #90 (merged). Addresses the serialization gap flagged
by @punitarani in the review comment —
digit-prefixed airline codes like _3F were still leaking into API
requests and CLI output through paths not covered by the first PR.

Changes

• removeprefix("_") in flights.py and dates.py serialize()
  functions — strip the synthetic underscore before sending codes to
  Google Flights API
• serialize_airline() in cli/utils.py — same fix for CLI JSON output
• Round-trip selected_flight in flights.py — pass enum objects
  (leg.airline, leg.departure_airport, leg.arrival_airport) to
  serialize() instead of pre-resolving .name, which bypassed the
  isinstance check and leaked _3F into the request payload
• Test for serialize_airline() with numeric-prefix code

Why removeprefix over lstrip

lstrip("_") would strip all leading underscores (__3F → 3F).
removeprefix("_") removes exactly one — matching the single underscore
added by generate_enums.py for digit-starting IATA codes.

Test plan

• serialize_airline(Airline._3F) returns {"code": "3F", "name": "FlyOne Armenia"}
• All 6 airline-related tests pass
• No regressions in existing tests

Greptile Summary

This follow-up PR closes the remaining serialization gaps from #90, ensuring digit-prefixed airline codes like _3F are stripped to their canonical IATA form (3F) across all code paths: Google Flights API requests (flights.py, dates.py serialize functions), CLI JSON output (cli/utils.py serialize_airline), and input parsing (core/parsers.py parse_airlines). It also fixes a more subtle round-trip bug where selected_flight legs were passing .name strings into serialize(), bypassing the isinstance(obj, Airline) guard entirely.

Key changes:

• lstrip(\"_\") → removeprefix(\"_\") in cli/utils.py and both serialize() functions — prevents over-stripping if a code somehow contained multiple leading underscores
• dates.py serialize() — was the missed path from fix: correct stale airline data for 3F and fix numeric-prefix airline filtering #90; now consistent with flights.py
• flights.py round-trip selected_flight — now passes leg.departure_airport, leg.arrival_airport, and leg.airline enum objects (not .name strings) so the isinstance guard applies correctly
• parsers.py parse_airlines — correctly prefixes digit-leading codes with _ before enum lookup
• data/airlines.csv and Airline._3F enum — updated from "Pacific Airways" to "FlyOne Armenia"
• Two new tests covering the numeric-prefix round-trip

One gap remains: fli/cli/commands/dates.py line 234 builds the query echo with airline.name (post-parse enum names), so \"_3F\" still leaks into the query.airlines field of the JSON output for the dates command.

Confidence Score: 4/5

Safe to merge with the minor caveat that the dates command's JSON query echo still leaks the underscore prefix for digit-prefixed airlines.

All API serialization paths and CLI result output are correctly fixed. The one remaining defect is in the informational query-echo field of the dates command JSON output (fli/cli/commands/dates.py:234), which was explicitly part of the PR's stated goal ("CLI output" leaks) but was missed. This is a real, user-visible inconsistency rather than a pure style issue, warranting a 4 rather than 5.

fli/cli/commands/dates.py — line 234 still uses airline.name without removeprefix("_") in the query echo dict.

Important Files Changed

Filename	Overview
fli/models/google_flights/flights.py	Fixed serialize() to call removeprefix("_") on Airline/Airport names, and fixed selected_flight round-trip serialization to pass enum objects instead of raw .name strings — correctly routes through the isinstance guard.
fli/models/google_flights/dates.py	Fixed the previously missed serialize() function to apply removeprefix("_"), closing the gap for date search API requests with digit-prefixed airline codes.
fli/core/parsers.py	parse_airlines now correctly maps user-supplied codes like "3F" to "_3F" enum keys before lookup, enabling round-trip input→enum→output without leaking the underscore.
fli/cli/utils.py	serialize_airline now strips the underscore prefix via removeprefix("_"), fixing JSON CLI output for digit-prefixed airline codes.
tests/cli/test_utils.py	Added test_parse_airlines_numeric_prefix and test_serialize_airline_numeric_prefix covering the two fixed code paths; assertions match the updated airline data.
fli/models/airline.py	_3F value updated from "Pacific Airways" to "FlyOne Armenia" to match the airlines.csv data correction.
data/airlines.csv	3F airline name corrected from "Pacific Airways" to "FlyOne Armenia".

Flowchart

%%{init: {'theme': 'neutral'}}%%
flowchart TD
    UserInput["User input: '3F'"] --> ParseAirlines["parse_airlines()\ncore/parsers.py\ncode[0].isdigit() → prepend '_'"]
    ParseAirlines --> EnumLookup["getattr(Airline, '_3F')\n→ Airline._3F"]
    EnumLookup --> TwoPaths{Output path}

    TwoPaths -->|API request| Serialize["serialize(obj)\nflights.py / dates.py\nobj.name.removeprefix('_')\n→ '3F' ✅"]
    TwoPaths -->|CLI JSON results| SerializeAirline["serialize_airline()\ncli/utils.py\nairline.name.removeprefix('_')\n→ '3F' ✅"]
    TwoPaths -->|CLI JSON query echo\ndates command| QueryEcho["airline.name\ncli/commands/dates.py:234\n→ '_3F' ❌ still leaks"]

    Serialize --> APIRequest["Google Flights API\nrequest payload"]
    SerializeAirline --> CLIOutput["CLI / MCP\nflight results"]
    QueryEcho --> QueryField["query.airlines field\nin JSON response"]

Loading

Comments Outside Diff (1)

1. fli/cli/commands/dates.py, line 234 (link)

   Underscore prefix still leaks in query echo

   This line serializes parsed Airline enum names directly into the JSON query field. For digit-prefixed codes like Airline._3F, airline.name returns "_3F" rather than the user-supplied "3F". This is one of the serialization paths the PR description explicitly targets ("digit-prefixed airline codes … still leaking into … CLI output"), but it was missed here.

   The flights command works correctly because it echoes the raw input strings before parsing. The dates command echoes the post-parsed Airline.name, so the prefix leaks.

   Prompt To Fix With AI

   This is a comment left during a code review.
   Path: fli/cli/commands/dates.py
   Line: 234
   
   Comment:
   **Underscore prefix still leaks in query echo**
   
   This line serializes parsed `Airline` enum names directly into the JSON `query` field. For digit-prefixed codes like `Airline._3F`, `airline.name` returns `"_3F"` rather than the user-supplied `"3F"`. This is one of the serialization paths the PR description explicitly targets ("digit-prefixed airline codes … still leaking into … CLI output"), but it was missed here.
   
   The `flights` command works correctly because it echoes the raw input strings before parsing. The `dates` command echoes the post-parsed `Airline.name`, so the prefix leaks.
   
   
   
   How can I resolve this? If you propose a fix, please make it concise.

Prompt To Fix All With AI

This is a comment left during a code review.
Path: fli/cli/commands/dates.py
Line: 234

Comment:
**Underscore prefix still leaks in query echo**

This line serializes parsed `Airline` enum names directly into the JSON `query` field. For digit-prefixed codes like `Airline._3F`, `airline.name` returns `"_3F"` rather than the user-supplied `"3F"`. This is one of the serialization paths the PR description explicitly targets ("digit-prefixed airline codes … still leaking into … CLI output"), but it was missed here.

The `flights` command works correctly because it echoes the raw input strings before parsing. The `dates` command echoes the post-parsed `Airline.name`, so the prefix leaks.

```suggestion
            "airlines": [airline.name.removeprefix("_") for airline in parsed_airlines] if parsed_airlines else None,
```

How can I resolve this? If you propose a fix, please make it concise.

_{Reviews (2): Last reviewed commit: "fix: strip underscore prefix from digit-..." | Re-trigger Greptile}

_{(4/5) You can add custom instructions or style guidelines for the agent here!}

[punitarani]

lgtm just need to fix merge conflict

i can test locally and merge once fixed

[ktrufanov-skycop]

Superseded — rebased onto current main in a new PR.

[ktrufanov-skycop]

CI failure on Python 3.13 is a network timeout in test_complex_round_trip_search (curl timeout hitting Google Flights API) — not related to this change. All other matrix jobs (3.10, 3.11, 3.12) and lint pass cleanly.