Raise error when query stats not enabled

.travis.yml

@@ -2,7 +2,7 @@ language: ruby
 rvm: 2.2.4
 cache: bundler
 sudo: false
-script: TRAVIS_CI=1 bundle exec rake test
+script: bundle exec rake test
 before_script:
   - psql -c 'create database pghero_test;' -U postgres
 notifications:

lib/pghero.rb

@@ -26,6 +26,8 @@
 require "pghero/query_stats"
 
 module PgHero
+  class MissingRequirement < StandardError; end
+
   # settings
   class << self
     attr_accessor :long_running_query_sec, :slow_query_ms, :slow_query_calls, :total_connections_threshold, :cache_hit_rate_threshold, :env, :show_migrations

lib/pghero/methods/basic.rb

@@ -21,8 +21,9 @@ def settings
 
       def ssl_used?
         ssl_used = nil
-        with_transaction do
-          execute("CREATE EXTENSION IF NOT EXISTS sslinfo")
+        with_transaction(rollback: true) do
+          # rescue if not superuser
+          execute("CREATE EXTENSION IF NOT EXISTS sslinfo") rescue nil
           ssl_used = select_one("SELECT ssl_is_used()")
         end
         ssl_used
@@ -33,7 +34,11 @@ def database_name
       end
 
       def server_version
-        select_one("SHOW server_version")
+        @server_version ||= select_one("SHOW server_version")
+      end
+
+      def server_version_num
+        @server_version_num ||= select_one("SHOW server_version_num").to_i
       end
 
       private

lib/pghero/methods/query_stats.rb

@@ -3,7 +3,7 @@ module Methods
     module QueryStats
       def query_stats(historical: false, start_at: nil, end_at: nil, min_average_time: nil, min_calls: nil, **options)
         current_query_stats = historical && end_at && end_at < Time.now ? [] : current_query_stats(options)
-        historical_query_stats = historical ? historical_query_stats(start_at: start_at, end_at: end_at, **options) : []
+        historical_query_stats = historical && historical_query_stats_enabled? ? historical_query_stats(start_at: start_at, end_at: end_at, **options) : []
 
         query_stats = combine_query_stats((current_query_stats + historical_query_stats).group_by { |q| [q[:query_hash], q[:user]] })
         query_stats = combine_query_stats(query_stats.group_by { |q| [normalize_query(q[:query]), q[:user]] })
@@ -55,12 +55,10 @@ def disable_query_stats
       end
 
       def reset_query_stats
-        if query_stats_enabled?
-          execute("SELECT pg_stat_statements_reset()")
-          true
-        else
-          false
-        end
+        execute("SELECT pg_stat_statements_reset()")
+        true
+      rescue ActiveRecord::StatementInvalid
+        false
       end
 
       # http://stackoverflow.com/questions/20582500/how-to-check-if-a-table-exists-in-a-given-schema
@@ -200,7 +198,7 @@ def current_query_stats(limit: nil, sort: nil, database: nil, query_hash: nil)
             LIMIT #{limit.to_i}
           SQL
         else
-          []
+          raise MissingRequirement, "Query stats not enabled"
         end
       end
 
@@ -244,14 +242,10 @@ def historical_query_stats(sort: nil, start_at: nil, end_at: nil, query_hash: ni
             LIMIT 100
           SQL
         else
-          []
+          raise MissingRequirement, "Historical query stats not enabled"
         end
       end
 
-      def server_version_num
-        @server_version ||= select_one("SHOW server_version_num").to_i
-      end
-
       def combine_query_stats(grouped_stats)
         query_stats = []
         grouped_stats.each do |_, stats2|

test/suggested_indexes_test.rb

@@ -2,9 +2,6 @@
 
 class SuggestedIndexesTest < Minitest::Test
   def setup
-    # no pg_stat_statements
-    skip if ENV["TRAVIS_CI"]
-
     PgHero.reset_query_stats
   end
 

test/test_helper.rb

@@ -10,6 +10,8 @@
 
 ActiveRecord::Base.establish_connection adapter: "postgresql", database: "pghero_test"
 
+ActiveRecord::Migration.enable_extension "pg_stat_statements"
+
 ActiveRecord::Migration.create_table :cities, force: true do |t|
   t.string :name
 end