metadataHeaders array not expanded as repeated query params in gmail.users.messages.get

[jraitt]

Description

When using gws gmail users messages get with format=metadata and metadataHeaders as an array, the array is stringified instead of being expanded into repeated query parameters.

Steps to Reproduce

gws gmail users messages get --params '{"userId":"me","id":"<msg_id>","format":"metadata","metadataHeaders":["From","Subject","Date"]}' --dry-run

Expected

"query_params": {
  "format": "metadata",
  "metadataHeaders": ["From", "Subject", "Date"]
}

With the HTTP request containing: ?format=metadata&metadataHeaders=From&metadataHeaders=Subject&metadataHeaders=Date

Actual

"query_params": {
  "format": "metadata",
  "metadataHeaders": "[\"From\",\"Subject\",\"Date\"]"
}

The array is stringified as a single value, so the Gmail API ignores it and returns no headers.

Root Cause

gws schema gmail.users.messages.get shows metadataHeaders without repeated: true:

"metadataHeaders": {
  "description": "When given and format is METADATA, only include headers specified.",
  "location": "query",
  "required": false,
  "type": "string"
}

But the Gmail Discovery Doc at https://gmail.googleapis.com/$discovery/rest?version=v1 has:

"metadataHeaders": {
  "description": "When given and format is METADATA, only include headers specified.",
  "location": "query",
  "repeated": true,
  "type": "string"
}

The repeated field is being dropped when gws parses/caches the Discovery Document, so build_url() treats the array as a non-repeated param and stringifies it.

Environment

• gws v0.11.1
• macOS (arm64)

Workaround

Use format=full instead of format=metadata — returns all headers but with more data than necessary.