Send HTML to campfire instead of JSON

app/models/webhook/delivery.rb

@@ -103,7 +103,7 @@ class Webhook::Delivery < ApplicationRecord
     def headers
       {
         "User-Agent" => USER_AGENT,
-        "Content-Type" => "application/json",
+        "Content-Type" => content_type,
         "X-Webhook-Signature" => signature,
         "X-Webhook-Timestamp" => event.created_at.utc.iso8601
       }
@@ -113,6 +113,14 @@ class Webhook::Delivery < ApplicationRecord
       OpenSSL::HMAC.hexdigest("SHA256", webhook.signing_secret, payload)
     end
 
+    def content_type
+      if webhook.for_campfire?
+        "text/html"
+      else
+        "application/json"
+      end
+    end
+
     def payload
       @payload ||= if webhook.for_basecamp?
         { line: { content: render_payload(formats: :html) } }.to_json

test/models/webhook/delivery_test.rb

@@ -127,7 +127,8 @@ class Webhook::DeliveryTest < ActiveSupport::TestCase
     request_stub = stub_request(:post, webhook.url)
       .with do |request|
         body = JSON.parse(request.body)
-        body.key?("line") && body["line"].key?("content") && body["line"]["content"].present?
+        body.key?("line") && body["line"].key?("content") && body["line"]["content"].present? &&
+        request.headers["Content-Type"] == "application/json"
       end
       .to_return(status: 200)
 
@@ -148,7 +149,8 @@ class Webhook::DeliveryTest < ActiveSupport::TestCase
 
     request_stub = stub_request(:post, webhook.url)
       .with do |request|
-        request.body.is_a?(String) && !request.body.start_with?("{") && request.body.present?
+        request.body.is_a?(String) && !request.body.start_with?("{") && request.body.present? &&
+        request.headers["Content-Type"] == "text/html"
       end
       .to_return(status: 200)
 
@@ -170,7 +172,8 @@ class Webhook::DeliveryTest < ActiveSupport::TestCase
     request_stub = stub_request(:post, webhook.url)
       .with do |request|
         body = JSON.parse(request.body)
-        body.key?("text") && body["text"].present?
+        body.key?("text") && body["text"].present? &&
+        request.headers["Content-Type"] == "application/json"
       end
       .to_return(status: 200)
 
@@ -192,7 +195,8 @@ class Webhook::DeliveryTest < ActiveSupport::TestCase
     request_stub = stub_request(:post, webhook.url)
       .with do |request|
         body = JSON.parse(request.body)
-        body.present? && !body.key?("line") && !body.key?("text")
+        body.present? && !body.key?("line") && !body.key?("text") &&
+        request.headers["Content-Type"] == "application/json"
       end
       .to_return(status: 200)