Apply reviewer feedback59587-add-graphql-logging

- Comply doc with guidelines
- Improve tests for readability and completeness
- Separate out phases visually with newlines
- Add `format_message` test
- test readability
- code and test structure/styling
- static query analyzers
- call `as_json` on `provided_variables`
- add exception handling

1 files changed, 27 insertions, 21 deletions

diff --git a/lib/gitlab/graphql/query_analyzers/logger_analyzer.rb b/lib/gitlab/graphql/query_analyzers/logger_analyzer.rb
index 8119d232124..01b55a1667f 100644
--- a/lib/gitlab/graphql/query_analyzers/logger_analyzer.rb
+++ b/lib/gitlab/graphql/query_analyzers/logger_analyzer.rb
@@ -4,18 +4,22 @@ module Gitlab
   module Graphql
     module QueryAnalyzers
       class LoggerAnalyzer
+        COMPLEXITY_ANALYZER = GraphQL::Analysis::QueryComplexity.new { |query, complexity_value| complexity_value }
+        DEPTH_ANALYZER = GraphQL::Analysis::QueryDepth.new { |query, depth_value| depth_value }
+
         def analyze?(query)
           Feature.enabled?(:graphql_logging, default_enabled: true)
         end
 
         def initial_value(query)
-          {
-            time_started: Gitlab::Metrics::System.monotonic_time,
+          variables = process_variables(query.provided_variables)
+          default_initial_values(query).merge({
             query_string: query.query_string,
-            query: query,
-            variables: process_variables(query.provided_variables),
-            duration: nil
-          }
+            variables: variables
+          })
+        rescue => e
+          Gitlab::Sentry.track_exception(e)
+          default_initial_values(query)
         end
 
         def call(memo, visit_type, irep_node)
@@ -23,7 +27,9 @@ module Gitlab
         end
 
         def final_value(memo)
-          analyzers = [complexity_analyzer, depth_analyzer]
+          return if memo.nil?
+
+          analyzers = [COMPLEXITY_ANALYZER, DEPTH_ANALYZER]
           complexity, depth = GraphQL::Analysis.analyze_query(memo[:query], analyzers)
 
           memo[:depth] = depth
@@ -31,34 +37,34 @@ module Gitlab
           memo[:duration] = duration(memo[:time_started]).round(1)
 
           GraphqlLogger.info(memo.except!(:time_started, :query))
+        rescue => e
+          Gitlab::Sentry.track_exception(e)
         end
 
         private
 
         def process_variables(variables)
-          if variables.respond_to?(:to_json)
-            variables.to_json
+          if variables.respond_to?(:to_s)
+            variables.to_s
           else
             variables
           end
         end
 
-        def complexity_analyzer
-          GraphQL::Analysis::QueryComplexity.new do |query, complexity_value|
-            complexity_value
-          end
-        end
-
-        def depth_analyzer
-          GraphQL::Analysis::QueryDepth.new do |query, depth_value|
-            depth_value
-          end
-        end
-
         def duration(time_started)
           nanoseconds = Gitlab::Metrics::System.monotonic_time - time_started
           nanoseconds * 1000000
         end
+
+        def default_initial_values(query)
+          {
+            time_started: Gitlab::Metrics::System.monotonic_time,
+            query_string: nil,
+            query: query,
+            variables: nil,
+            duration: nil
+          }
+        end
       end
     end
   end