fix(gmail): match message headers case-insensitively (#642)

[lucaspretti]

Summary

gws gmail +reply-all silently drops Cc recipients when the original message's Cc header arrives with non-canonical casing (e.g. CC), which is common with Microsoft Exchange / Outlook. The original To recipients survive but the entire Cc list is lost, so a reply-all can go out missing people from the thread with no error.

Root cause

parse_message_headers (crates/google-workspace-cli/src/helpers/gmail/mod.rs) matched header names with an exact, case-sensitive match. Per RFC 5322 §1.2.2 header field names are case-insensitive, and the Gmail API preserves the original casing from the sending MTA, so CC (and any other non-canonical casing) fell through to _ => {} and was silently dropped.

Fix

Match on the lowercased header name so all casings are recognized. This also folds the previous "Message-ID" | "Message-Id" special-case into a single "message-id" arm.

Test

Adds test_parse_original_message_case_insensitive_headers, which feeds Exchange-style casing (FROM, TO, CC, cc, message-id) and asserts every recipient and the message id are parsed (i.e. Cc is not dropped).

Fixes #642

[changeset-bot]

🦋 Changeset detected

Latest commit: 68e85e5

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 1 package

Name	Type
@googleworkspace/cli	Patch

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[gemini-code-assist]

Summary of Changes

Hello, I'm Gemini Code Assist¹! I'm currently reviewing this pull request and will post my feedback shortly. In the meantime, here's a summary to help you and other reviewers quickly get up to speed!

This pull request addresses an issue where Gmail message headers with non-canonical casing were being silently ignored during parsing. By normalizing header names to lowercase before matching, the system now correctly handles various casing formats, ensuring that critical recipient information is preserved during reply-all operations.

Highlights

• Case-Insensitive Header Parsing: Updated the Gmail message header parsing logic to use case-insensitive matching, ensuring headers like 'CC' are correctly identified regardless of their casing.
• Regression Testing: Added a new test case to verify that non-canonical header casing from external MTAs (like Microsoft Exchange) is correctly parsed, preventing silent recipient drops.

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[gemini-code-assist]

Code Review

This pull request updates the Gmail message header parsing logic to be case-insensitive, adhering to RFC 5322 §1.2.2. By converting header names to ASCII lowercase before matching, it ensures that headers with non-canonical casing (such as 'CC' or 'FROM') are not silently dropped. A new unit test has been added to verify this behavior. I have no feedback to provide.

[googleworkspace-bot]

/gemini review

[gemini-code-assist]

Code Review

This pull request updates the Gmail message header parsing in crates/google-workspace-cli/src/helpers/gmail/mod.rs to be case-insensitive, adhering to RFC 5322 §1.2.2. By converting header names to ASCII lowercase before matching, it ensures that headers with non-canonical casing (such as 'CC' or 'FROM') are not silently dropped. A new unit test has been added to verify this behavior. I have no feedback to provide.

[lucaspretti]

@googlebot I signed it!

[lucaspretti]

@googlebot I signed it!

[lucaspretti]

@googlebot I signed it!

[googleworkspace-bot]

/gemini review

[gemini-code-assist]

Code Review

This pull request fixes Gmail message header parsing to be case-insensitive (per RFC 5322 §1.2.2) by converting header names to lowercase before matching. This prevents headers with non-canonical casing (such as 'CC' from Microsoft Exchange or Outlook) from being silently dropped. A unit test has been added to verify this behavior. There are no review comments, so I have no feedback to provide.