Fix whitespace normalization to preserve SQL quoted strings in ERB templates

The previous implementation of prepare_query used a simple regex to normalize
whitespace, which incorrectly modified content inside SQL quoted strings when
preparing queries for logs. This caused issues with multiline ERB templates
where string literals could be corrupted.

Changes:
- Refactored prepare_query to render ERB first, then normalize whitespace
- Added regex pattern to match quoted strings and preserve their content
- Only whitespace outside of quotes is normalized to single spaces
- Simplified test database configuration to use consistent postgres setup
- Added test coverage for multiline ERB templates with quoted strings

This fix ensures that SQL string literals remain intact while still providing
clean, single-line output for logging purposes.

Author: sufleR

lib/sql_query.rb

@@ -78,8 +78,16 @@ def initialize
 
   def prepare_query(for_logs)
     query_template = File.read(file_path)
-    query_template = query_template.gsub(/(\n|\s)+/, ' ') if for_logs
-    ERB.new(query_template).result(binding)
+    rendered_sql = ERB.new(query_template).result(binding)
+
+    return rendered_sql unless for_logs
+
+    # Normalize whitespace while preserving SQL quoted strings
+    # Matches: 'single-quoted' OR "double-quoted" OR (whitespace)
+    # Only captures whitespace when NOT inside quotes
+    rendered_sql.gsub(/'(?:[^'\\]|\\.)*'|"(?:[^"\\]|\\.)*"|(\s+)/) do |match|
+      $1 ? ' ' : match  # Replace whitespace with space, preserve quoted strings
+    end
   end
 
   def split_to_path_and_name(file)

spec/spec_helper.rb

@@ -33,23 +33,13 @@ def BigDecimal.new(...)
     mocks.verify_partial_doubles = true
   end
 
-  connection_config = if ENV['CI']
-                        {
-                          adapter: 'postgresql',
-                          host: 'localhost',
-                          username: 'postgres',
-                          password: 'postgres',
-                          database: 'sqlquery_test'
-                        }
-                      else
-                        {
-                          adapter: 'postgresql',
-                          host: 'localhost',
-                          username: 'sqlquery',
-                          password: 'sqlquery',
-                          database: 'sqlquery'
-                        }
-                      end
+  connection_config = {
+    adapter: 'postgresql',
+    host: 'localhost',
+    username: 'postgres',
+    password: 'postgres',
+    database: 'sqlquery_test'
+  }
 
   ActiveRecord::Base.establish_connection(connection_config)
 

spec/sql_queries/multiline_erb.sql.erb

@@ -0,0 +1,9 @@
+<%
+  field1 = @field1 || 'default1'
+  field2 = @field2 || 'default2'
+%>
+SELECT
+  <%= quote field1 %> as field1,
+  <%= quote field2 %> as field2
+FROM players
+WHERE email = <%= quote @email %>

spec/sql_query_spec.rb

@@ -211,6 +211,22 @@ class Model < ActiveRecord::Base
           .to eq("SELECT * FROM players WHERE email = '   e@mail.dev   ' ")
       end
     end
+
+    context 'when template has multiline ERB blocks' do
+      let(:file_name) { :multiline_erb }
+      let(:options) { { email: 'test@dev.com', field1: 'val1', field2: 'val2' } }
+      let(:query) { described_class.new(file_name, options) }
+
+      it 'processes multiline ERB correctly without syntax errors' do
+        expect { query.prepared_for_logs }.not_to raise_error
+      end
+
+      it 'includes rendered values in prepared_for_logs output' do
+        result = query.prepared_for_logs
+        expect(result).to include("'val1' as field1")
+        expect(result).to include("'val2' as field2")
+      end
+    end
   end
 
   describe '.config' do