Expose Slack profile synchronization failures

app/jobs/slack_profile_sync_job.rb

@@ -22,5 +22,6 @@ def perform(user_id)
     retry_job(wait: [ e.retry_after, polynomial_delay ].max.seconds)
   rescue => e
     report_error(e, message: "Failed to update Slack username and avatar for user #{user_id}")
+    raise
   end
 end

app/models/concerns/slack_integration.rb

@@ -1,6 +1,13 @@
 module SlackIntegration
   extend ActiveSupport::Concern
 
+  class ApiError < StandardError
+    def initialize(error, status: nil)
+      details = [ status && "HTTP #{status}", error ].compact.join(": ")
+      super("Slack profile API request failed: #{details}")
+    end
+  end
+
   class RateLimitedError < StandardError
     attr_reader :retry_after
 
@@ -30,10 +37,11 @@ def raw_slack_user_info
     response = HTTP.auth("Bearer #{access_token}")
       .get("https://slack.com/api/users.info?user=#{slack_uid}")
     raise RateLimitedError, response.headers["Retry-After"] if response.status.code == 429
-    return nil unless response.status.success?
 
     data = JSON.parse(response.body.to_s)
-    data["user"] if data["ok"]
+    raise ApiError.new(data["error"] || "unexpected response", status: response.status.code) unless response.status.success? && data["ok"]
+
+    data.fetch("user")
   end
 
   def update_from_slack

test/jobs/slack_profile_sync_job_test.rb

@@ -65,7 +65,7 @@ class SlackProfileSyncJobTest < ActiveJob::TestCase
     assert_nil user.slack_synced_at
   end
 
-  test "preserves the existing profile when Slack returns an API error" do
+  test "fails visibly and preserves the existing profile when Slack returns an API error" do
     synced_at = 2.days.ago
     user = User.create!(
       timezone: "UTC",
@@ -75,10 +75,13 @@ class SlackProfileSyncJobTest < ActiveJob::TestCase
       slack_synced_at: synced_at
     )
     stub_request(:get, "https://slack.com/api/users.info?user=U_API_ERROR")
-      .to_return(status: 500, body: { ok: false, error: "internal_error" }.to_json)
+      .to_return(body: { ok: false, error: "missing_scope" }.to_json)
 
-    SlackProfileSyncJob.perform_now(user.id)
+    error = assert_raises(SlackIntegration::ApiError) do
+      SlackProfileSyncJob.perform_now(user.id)
+    end
 
+    assert_includes error.message, "missing_scope"
     user.reload
     assert_equal "existing-name", user.slack_username
     assert_equal "https://example.com/existing-avatar.png", user.slack_avatar_url