fix: handle header null values (#92)

Author: drish

lib/resend/mailer.rb

@@ -92,6 +92,11 @@ def get_headers(mail)
       params
     end
 
+    # Remove nils from header values
+    def cleanup_headers(headers)
+      headers.delete_if { |_k, v| v.nil? }
+    end
+
     # Gets the values of the headers that are set through the `#mail` method
     #
     # @param Mail mail Rails Mail object
@@ -101,6 +106,7 @@ def mail_headers_values(mail)
       mail[:headers].unparsed_value.each do |k, v|
         params[k.to_s] = v
       end
+      cleanup_headers(params)
       params
     end
 
@@ -113,8 +119,7 @@ def headers_values(mail)
       unignored_headers(mail).each do |h|
         params[h.name.to_s] = h.unparsed_value
       end
-      # remove nil header values
-      params.delete_if { |_k, v| v.nil? }
+      cleanup_headers(params)
       params
     end
 

lib/resend/request.rb

@@ -35,6 +35,7 @@ def perform
       }
 
       options[:body] = @body.to_json unless @body.empty?
+
       resp = HTTParty.send(@verb.to_sym, "#{BASE_URL}#{@path}", options)
 
       check_json!(resp)

lib/resend/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Resend
-  VERSION = "0.17.1"
+  VERSION = "0.17.2"
 end

spec/railtie/mailer_spec.rb

@@ -54,7 +54,10 @@ def with_overwritten_headers(to, subject)
 
   def with_nil_header_values(to, subject)
     headers["X-Entity-Ref-ID"] = nil
-    mail(to: to, subject: subject) do |format|
+    mail(to: to, subject: subject, headers: {
+      "custom-header1": nil,
+      "custom-header2": "v2"
+    }) do |format|
       format.text { render plain: "txt" }
       format.html { render html: "<p>html</p>".html_safe }
     end
@@ -157,6 +160,6 @@ class TestMailerWithDisplayName < TestMailer
   it "#build_resend_params handles nil values" do
     message = TestMailer.with_nil_header_values("[email protected]", "Test!")
     body = @mailer.build_resend_params(message)
-    expect(body[:headers]).to be nil
+    expect(body[:headers].keys).to eq(["custom-header2"])
   end
 end