Use Typecast for JSON serialization in Cloud migrate/push

Replace direct JSON.generate/JSON.parse calls with Typecast.to_json and
Typecast.from_json for consistency with the rest of the codebase. Add
CLAUDE.md guidance on using Typecast and Http::Client.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: jnunemaker

CLAUDE.md

@@ -69,6 +69,14 @@ The project is structured as multiple gems:
 **Memoization**: Automatic caching of feature checks within request/thread scope
 **Type Safety**: Strong typing system for actors, percentages, and other values
 
+### Serialization and HTTP
+
+Use `Flipper::Typecast` for JSON and gzip serialization instead of calling `JSON.generate`/`JSON.parse` or `Zlib` directly:
+- `Typecast.to_json(hash)` / `Typecast.from_json(string)` for JSON serialization
+- `Typecast.to_gzip(string)` / `Typecast.from_gzip(string)` for gzip compression
+
+For outbound HTTP requests, use `Flipper::Adapters::Http::Client` instead of raw `Net::HTTP`. It provides timeouts, retries (`max_retries`), SSL verification, and diagnostic headers (user-agent, client-language, client-platform, etc.). See `lib/flipper/cloud/migrate.rb` for an example.
+
 ### Testing
 
 Uses both RSpec (currently preferred for new tests) and Minitest. Shared adapter specs ensure consistency across all storage backends. Extensive testing across multiple Rails versions (5.0-8.0).

lib/flipper/cloud/migrate.rb

@@ -1,4 +1,3 @@
-require "json"
 require "flipper/adapters/http/client"
 require "flipper/typecast"
 
@@ -17,18 +16,18 @@ module Cloud
     def self.migrate(flipper = Flipper, app_name: nil)
       export = flipper.export(format: :json, version: 1)
       payload = {
-        export: JSON.parse(export.contents),
+        export: Typecast.from_json(export.contents),
         metadata: {app_name: app_name},
       }
 
       client = build_client("/api")
-      response = client.post("/migrate", Typecast.to_gzip(JSON.generate(payload)))
-      body = JSON.parse(response.body) rescue {}
+      response = client.post("/migrate", Typecast.to_gzip(Typecast.to_json(payload)))
+      body = Typecast.from_json(response.body) rescue nil
 
       MigrateResult.new(
         code: response.code.to_i,
-        url: body["url"],
-        message: body["error"],
+        url: body&.dig("url"),
+        message: body&.dig("error"),
       )
     end
 
@@ -45,12 +44,12 @@ def self.push(token, flipper = Flipper)
         "flipper-cloud-token" => token,
       })
       response = client.post("/import", Typecast.to_gzip(export.contents))
-      body = JSON.parse(response.body) rescue {}
+      body = Typecast.from_json(response.body) rescue nil
 
       MigrateResult.new(
         code: response.code.to_i,
         url: nil,
-        message: body["error"],
+        message: body&.dig("error"),
       )
     end