Merge pull request #461 from berkeley-cdss/cycomachead/158-is-there-anything-in-the-staging-environment-that-prevents-emails-from-being-sent-out-what-is-the/1

Redirect Staging Emails

Author: cycomachead

app/mailers/staging_email_interceptor.rb

@@ -0,0 +1,23 @@
+# frozen_string_literal: true
+
+# ActionMailer interceptor used in the staging environment to ensure we never
+# email real people. Every outgoing message is redirected to a single safe
+# staging mailbox, and the original recipient(s) are preserved in the subject
+# line so the rendered email can still be inspected.
+#
+# Registered in config/environments/staging.rb via:
+#   config.action_mailer.interceptors = %w[StagingEmailInterceptor]
+class StagingEmailInterceptor
+  # Address that all staging mail is redirected to. Can be overridden with the
+  # STAGING_EMAIL_OVERRIDE env var if a different staging inbox is desired.
+  DEFAULT_OVERRIDE = 'flextensions@berkeley.edu'
+
+  def self.delivering_email(message)
+    original_recipients = Array(message.to).join(', ')
+    message.subject = "[STAGING -> #{original_recipients}] #{message.subject}"
+
+    message.to  = ENV.fetch('STAGING_EMAIL_OVERRIDE', DEFAULT_OVERRIDE)
+    message.cc  = nil
+    message.bcc = nil
+  end
+end

config/environments/staging.rb

@@ -10,6 +10,8 @@
   # Show full error reports, OK because staging is behind a VPN
   config.consider_all_requests_local = true
 
-  # TODO: Configure ActionMailer to re-write emails to send to staging addresses
-  # config.action_mailer.perform_deliveries = false
+  # Ensure staging never emails real people: redirect every outgoing message to
+  # a single safe staging mailbox, preserving the original recipient(s) in the
+  # subject line. See StagingEmailInterceptor.
+  config.action_mailer.interceptors = %w[StagingEmailInterceptor]
 end

spec/mailers/staging_email_interceptor_spec.rb

@@ -0,0 +1,55 @@
+# spec/mailers/staging_email_interceptor_spec.rb
+require 'rails_helper'
+
+RSpec.describe StagingEmailInterceptor do
+  def build_message(to:, subject:, cc: nil, bcc: nil)
+    Mail.new do
+      to to
+      cc cc if cc
+      bcc bcc if bcc
+      from 'flextensions@berkeley.edu'
+      subject subject
+      body 'Hello'
+    end
+  end
+
+  it 'redirects the recipient to the default staging mailbox' do
+    message = build_message(to: 'student@example.com', subject: 'Your extension')
+    described_class.delivering_email(message)
+
+    expect(message.to).to eq([ described_class::DEFAULT_OVERRIDE ])
+  end
+
+  it 'honors STAGING_EMAIL_OVERRIDE when set' do
+    message = build_message(to: 'student@example.com', subject: 'Your extension')
+
+    allow(ENV).to receive(:fetch).and_call_original
+    allow(ENV).to receive(:fetch)
+      .with('STAGING_EMAIL_OVERRIDE', described_class::DEFAULT_OVERRIDE)
+      .and_return('someone@example.com')
+
+    described_class.delivering_email(message)
+
+    expect(message.to).to eq([ 'someone@example.com' ])
+  end
+
+  it 'preserves the original recipient(s) in the subject line' do
+    message = build_message(to: %w[a@example.com b@example.com], subject: 'Your extension')
+    described_class.delivering_email(message)
+
+    expect(message.subject).to eq('[STAGING -> a@example.com, b@example.com] Your extension')
+  end
+
+  it 'strips cc and bcc so no real person is reached' do
+    message = build_message(
+      to: 'student@example.com',
+      subject: 'Your extension',
+      cc: 'ta@example.com',
+      bcc: 'instructor@example.com'
+    )
+    described_class.delivering_email(message)
+
+    expect(message.cc).to be_nil
+    expect(message.bcc).to be_nil
+  end
+end