chore: support merging configuration hashes when overriding (#611)

PACT-1033

lib/pact_broker/api/middleware/configuration.rb

@@ -1,5 +1,7 @@
 require "pact_broker/logging"
 
+# Allows the load-time configuration to be overridden on a per-request basis (for Pactflow)
+
 module PactBroker
   module Api
     module Middleware

lib/pact_broker/configuration.rb

@@ -82,23 +82,14 @@ def self.default_configuration
 
     def override_runtime_configuration!(overrides)
       new_runtime_configuration = runtime_configuration.dup
-      valid_overrides = {}
-      invalid_overrides = {}
-
-      overrides.each do | key, value |
-        if new_runtime_configuration.respond_to?("#{key}=")
-          valid_overrides[key] = Anyway::AutoCast.call(value)
-        else
-          invalid_overrides[key] = Anyway::AutoCast.call(value)
-        end
-      end
+      valid_overrides, invalid_overrides = identify_valid_and_invalid_configuration_overrides(new_runtime_configuration, overrides)
 
       if logger.debug?
         logger.debug("Overridding runtime configuration", overrides: valid_overrides, ignoring: invalid_overrides)
       end
 
       valid_overrides.each do | key, value |
-        new_runtime_configuration.public_send("#{key}=", value)
+        override_or_merge_value(new_runtime_configuration, key, value)
       end
 
       self.runtime_configuration = new_runtime_configuration
@@ -220,5 +211,31 @@ def load_from_database!
       require "pact_broker/config/load"
       PactBroker::Config::Load.call(runtime_configuration)
     end
+
+    private
+
+    def identify_valid_and_invalid_configuration_overrides(new_runtime_configuration, overrides)
+      valid_overrides = {}
+      invalid_overrides = {}
+
+      overrides.each do | key, value |
+        if new_runtime_configuration.respond_to?("#{key}=")
+          valid_overrides[key] = Anyway::AutoCast.call(value)
+        else
+          invalid_overrides[key] = Anyway::AutoCast.call(value)
+        end
+      end
+
+      return valid_overrides, invalid_overrides
+    end
+
+    def override_or_merge_value(new_runtime_configuration, key, value)
+      # Do a merge if original value and new value are both hashes
+      if value.is_a?(Hash) && new_runtime_configuration.public_send(key).is_a?(Hash)
+        new_runtime_configuration.public_send("#{key}=", new_runtime_configuration.public_send(key).merge(value))
+      else
+        new_runtime_configuration.public_send("#{key}=", value)
+      end
+    end
   end
 end

spec/lib/pact_broker/configuration_spec.rb

@@ -38,38 +38,44 @@ module PactBroker
     describe "override_runtime_configuration!" do
       let(:logger) { double("logger", debug?: true, debug: nil, warn: nil) }
 
-      let(:duped_config) { PactBroker.configuration.dup }
+      let(:config) { PactBroker.configuration.dup }
 
-      it "overrides the specified runtime configuration attributes within the block" do
-        duped_config.override_runtime_configuration!(disable_ssl_verification: "true")
-        expect(duped_config.disable_ssl_verification).to eq true
+      it "overrides the specified runtime configuration attributes" do
+        config.override_runtime_configuration!(disable_ssl_verification: "true")
+        expect(config.disable_ssl_verification).to eq true
         expect(PactBroker.configuration.disable_ssl_verification).to eq false
       end
 
       it "logs the overrides at debug level" do
-        allow(duped_config).to receive(:logger).and_return(logger)
+        allow(config).to receive(:logger).and_return(logger)
         expect(logger).to receive(:debug).with("Overridding runtime configuration", hash_including(overrides: { disable_ssl_verification: true }))
-        duped_config.override_runtime_configuration!(disable_ssl_verification: "true")
+        config.override_runtime_configuration!(disable_ssl_verification: "true")
       end
 
-      it "does not override the other runtime configuration attributes within the block" do
-        attribute_in_block = PactBroker.configuration.webhook_scheme_whitelist
-        duped_config.override_runtime_configuration!(disable_ssl_verification: "true")
-        expect(duped_config.webhook_scheme_whitelist).to eq attribute_in_block
+      it "does not override the other runtime configuration attributes" do
+        expect { config.override_runtime_configuration!(disable_ssl_verification: "true") }.to_not change { config.webhook_scheme_whitelist }
       end
 
       context "when the specified runtime attribute does not exist" do
         it "logs that it has ignored those attributes" do
-          allow(duped_config).to receive(:logger).and_return(logger)
+          allow(config).to receive(:logger).and_return(logger)
           expect(logger).to receive(:debug).with("Overridding runtime configuration", hash_including(ignoring: { no_existy: true }))
-          duped_config.override_runtime_configuration!(no_existy: "true")
+          config.override_runtime_configuration!(no_existy: "true")
+        end
+      end
+
+      context "when overriding config items that are hashes" do
+        it "merges them" do
+          config.features = { feat_a: true, feat_b: false }
+          config.override_runtime_configuration!(features: { feat_a: false, feat_c: true })
+          expect(config.features).to eq feat_a: false, feat_b: false, feat_c: true
         end
       end
 
       context "when the configuration is frozen" do
         it "raises an error" do
-          duped_config.freeze
-          expect { duped_config.override_runtime_configuration!(disable_ssl_verification: "true") }.to raise_error FrozenError
+          config.freeze
+          expect { config.override_runtime_configuration!(disable_ssl_verification: "true") }.to raise_error FrozenError
         end
       end
     end