Introduce Configuration#validate (#2537)

* Introduce Configuration#validate

* Add a simple validate DSL to Configuration

* Remove unused method

* Construct error message in the validation itself

* Stricter specs

* Update CHANGELOG

* Fix spec for non-vernier setup

Author: solnic

CHANGELOG.md

@@ -4,6 +4,7 @@
 
 - Fix handling of cron with tz in Cron::Job ([#2530](https://github.com/getsentry/sentry-ruby/pull/2530))
 - Revert "[rails] support string errors in error reporter (#2464)" ([#2533](https://github.com/getsentry/sentry-ruby/pull/2533))
+- Removed unnecessary warning about missing `stackprof` when Vernier is configured as the profiler ([#2537](https://github.com/getsentry/sentry-ruby/pull/2537))
 
 ## 5.22.3
 

sentry-ruby/lib/sentry-ruby.rb

@@ -232,6 +232,7 @@ def init(&block)
       yield(config) if block_given?
       config.detect_release
       apply_patches(config)
+      config.validate
       client = Client.new(config)
       scope = Scope.new(max_breadcrumbs: config.max_breadcrumbs)
       hub = Hub.new(client, scope)

sentry-ruby/lib/sentry/configuration.rb

@@ -360,8 +360,47 @@ def post_initialization_callbacks
       def add_post_initialization_callback(&block)
         post_initialization_callbacks << block
       end
+
+      def validations
+        @validations ||= {}
+      end
+
+      def validate(attribute, optional: false, type: nil)
+        validations[attribute] = {
+          optional: optional,
+          type: type,
+          proc: build_validation_proc(optional, type)
+        }
+      end
+
+      private
+
+      def build_validation_proc(optional, type)
+        case type
+        when :numeric
+          ->(value) do
+            if optional && value.nil?
+              true
+            else
+              unless value.is_a?(Numeric)
+                message = "must be a Numeric"
+                message += " or nil" if optional
+
+                { error: message, value: value }
+              else
+                true
+              end
+            end
+          end
+        else
+          ->(value) { true }
+        end
+      end
     end
 
+    validate :traces_sample_rate, optional: true, type: :numeric
+    validate :profiles_sample_rate, optional: true, type: :numeric
+
     def initialize
       self.app_dirs_pattern = APP_DIRS_PATTERN
       self.debug = Sentry::Utils::EnvHelper.env_to_bool(ENV["SENTRY_DEBUG"])
@@ -417,6 +456,24 @@ def initialize
       run_post_initialization_callbacks
     end
 
+    def validate
+      if profiler_class == Sentry::Profiler && !defined?(StackProf)
+        log_warn("Please add the 'stackprof' gem to your Gemfile to use the StackProf profiler with Sentry.")
+      end
+
+      if profiler_class == Sentry::Vernier::Profiler && !defined?(Vernier)
+        log_warn("Please add the 'vernier' gem to your Gemfile to use the Vernier profiler with Sentry.")
+      end
+
+      self.class.validations.each do |attribute, validation|
+        value = public_send(attribute)
+
+        next if (result = validation[:proc].call(value)) === true
+
+        raise ArgumentError, result[:error]
+      end
+    end
+
     def dsn=(value)
       @dsn = init_dsn(value)
     end
@@ -489,18 +546,11 @@ def enable_tracing=(enable_tracing)
       @traces_sample_rate ||= 1.0 if enable_tracing
     end
 
-    def is_numeric_or_nil?(value)
-      value.is_a?(Numeric) || value.nil?
-    end
-
     def traces_sample_rate=(traces_sample_rate)
-      raise ArgumentError, "traces_sample_rate must be a Numeric or nil" unless is_numeric_or_nil?(traces_sample_rate)
       @traces_sample_rate = traces_sample_rate
     end
 
     def profiles_sample_rate=(profiles_sample_rate)
-      raise ArgumentError, "profiles_sample_rate must be a Numeric or nil" unless is_numeric_or_nil?(profiles_sample_rate)
-      log_warn("Please make sure to include the 'stackprof' gem in your Gemfile to use Profiling with Sentry.") unless defined?(StackProf)
       @profiles_sample_rate = profiles_sample_rate
     end
 
@@ -509,7 +559,6 @@ def profiler_class=(profiler_class)
         begin
           require "vernier"
         rescue LoadError
-          raise ArgumentError, "Please add the 'vernier' gem to your Gemfile to use the Vernier profiler with Sentry."
         end
       end
 

sentry-ruby/spec/sentry/configuration_spec.rb

@@ -90,7 +90,8 @@
     end
 
     it "raises ArgumentError when the value is not Numeric nor nil" do
-      expect { subject.traces_sample_rate = "foobar" }.to raise_error(ArgumentError)
+      expect { Sentry.init { |config| config.traces_sample_rate = "foobar" } }
+        .to raise_error(ArgumentError, "must be a Numeric or nil")
     end
   end
 
@@ -210,7 +211,8 @@
     end
 
     it "raises ArgumentError when the value is not Numeric nor nil" do
-      expect { subject.profiles_sample_rate = "foobar" }.to raise_error(ArgumentError)
+      expect { Sentry.init { |config| config.profiles_sample_rate = "foobar" } }
+        .to raise_error(ArgumentError, "must be a Numeric or nil")
     end
   end
 
@@ -703,12 +705,6 @@ class SentryConfigurationSample < Sentry::Configuration
     end
 
     it "sets the profiler class to StackProf when Vernier is not available", when: { ruby_version?: [:<, "3.2"] } do
-      expect { subject.profiler_class = Sentry::Vernier::Profiler }
-        .to raise_error(
-          ArgumentError,
-          /Please add the 'vernier' gem to your Gemfile/
-        )
-
       expect(subject.profiler_class).to eq(Sentry::Profiler)
     end
   end