Debian: Do not use symbols in fields names

Don't use symbols as keys in metadata, following the review comment:
https://gitlab.com/gitlab-org/gitlab/-/merge_requests/55896#note_532350725

app/services/packages/debian/extract_changes_metadata_service.rb

@@ -42,9 +42,9 @@ module Packages
       def files
         strong_memoize(:files) do
           raise ExtractionError.new("is not a changes file") unless file_type == :changes
-          raise ExtractionError.new("Files field is missing") if fields[:Files].blank?
-          raise ExtractionError.new("Checksums-Sha1 field is missing") if fields[:'Checksums-Sha1'].blank?
-          raise ExtractionError.new("Checksums-Sha256 field is missing") if fields[:'Checksums-Sha256'].blank?
+          raise ExtractionError.new("Files field is missing") if fields['Files'].blank?
+          raise ExtractionError.new("Checksums-Sha1 field is missing") if fields['Checksums-Sha1'].blank?
+          raise ExtractionError.new("Checksums-Sha256 field is missing") if fields['Checksums-Sha256'].blank?
 
           init_entries_from_files
           entries_from_checksums_sha1
@@ -56,7 +56,7 @@ module Packages
       end
 
       def init_entries_from_files
-        each_lines_for(:Files) do |line|
+        each_lines_for('Files') do |line|
           md5sum, size, section, priority, filename = line.split
           entry = FileEntry.new(
             filename: filename,
@@ -70,7 +70,7 @@ module Packages
       end
 
       def entries_from_checksums_sha1
-        each_lines_for(:'Checksums-Sha1') do |line|
+        each_lines_for('Checksums-Sha1') do |line|
           sha1sum, size, filename = line.split
           entry = @entries[filename]
           raise ExtractionError.new("#{filename} is listed in Checksums-Sha1 but not in Files") unless entry
@@ -81,7 +81,7 @@ module Packages
       end
 
       def entries_from_checksums_sha256
-        each_lines_for(:'Checksums-Sha256') do |line|
+        each_lines_for('Checksums-Sha256') do |line|
           sha256sum, size, filename = line.split
           entry = @entries[filename]
           raise ExtractionError.new("#{filename} is listed in Checksums-Sha256 but not in Files") unless entry

app/services/packages/debian/extract_metadata_service.rb

@@ -72,7 +72,7 @@ module Packages
 
       def extract_metadata
         fields = extracted_fields
-        architecture = fields.delete(:Architecture) if file_type_debian?
+        architecture = fields.delete('Architecture') if file_type_debian?
 
         {
           file_type: file_type,

app/services/packages/debian/parse_debian822_service.rb

@@ -26,7 +26,7 @@ module Packages
               section[field] += line[1..] unless paragraph_separator?(line)
             elsif match = match_section_line(line)
               section_name = match[:name] if section_name.nil?
-              field = match[:field].to_sym
+              field = match[:field]
 
               raise InvalidDebian822Error, "Duplicate field '#{field}' in section '#{section_name}'" if section.include?(field)
 

spec/services/packages/debian/extract_changes_metadata_service_spec.rb

@@ -13,7 +13,7 @@ RSpec.describe Packages::Debian::ExtractChangesMetadataService do
 
     context 'with valid package file' do
       it 'extract metadata', :aggregate_failures do
-        expected_fields = { 'Architecture': 'source amd64', 'Binary': 'libsample0 sample-dev sample-udeb' }
+        expected_fields = { 'Architecture' => 'source amd64', 'Binary' => 'libsample0 sample-dev sample-udeb' }
 
         expect(subject[:file_type]).to eq(:changes)
         expect(subject[:architecture]).to be_nil
@@ -40,7 +40,7 @@ RSpec.describe Packages::Debian::ExtractChangesMetadataService do
       let(:sha256_dsc) { '844f79825b7e8aaa191e514b58a81f9ac1e58e2180134b0c9512fa66d896d7ba 671 sample_1.2.3~alpha2.dsc' }
       let(:sha256_source) { 'b5a599e88e7cbdda3bde808160a21ba1dd1ec76b2ec8d4912aae769648d68362 864 sample_1.2.3~alpha2.tar.xz' }
       let(:sha256s) { "#{sha256_dsc}\n#{sha256_source}" }
-      let(:fields) { { Files: md5s, 'Checksums-Sha1': sha1s, 'Checksums-Sha256': sha256s } }
+      let(:fields) { { 'Files' => md5s, 'Checksums-Sha1' => sha1s, 'Checksums-Sha256' => sha256s } }
       let(:metadata) { { file_type: :changes, architecture: 'amd64', fields: fields } }
 
       before do

spec/services/packages/debian/extract_deb_metadata_service_spec.rb

@@ -10,17 +10,17 @@ RSpec.describe Packages::Debian::ExtractDebMetadataService do
   context 'with correct file' do
     it 'return as expected' do
       expected = {
-        'Package': 'libsample0',
-        'Source': 'sample',
-        'Version': '1.2.3~alpha2',
-        'Architecture': 'amd64',
-        'Maintainer': 'John Doe <john.doe@example.com>',
-        'Installed-Size': '7',
-        'Section': 'libs',
-        'Priority': 'optional',
-        'Multi-Arch': 'same',
-        'Homepage': 'https://gitlab.com/',
-        'Description': "Some mostly empty lib\nUsed in GitLab tests.\n\nTesting another paragraph."
+        'Package' => 'libsample0',
+        'Source' => 'sample',
+        'Version' => '1.2.3~alpha2',
+        'Architecture' => 'amd64',
+        'Maintainer' => 'John Doe <john.doe@example.com>',
+        'Installed-Size' => '7',
+        'Section' => 'libs',
+        'Priority' => 'optional',
+        'Multi-Arch' => 'same',
+        'Homepage' => 'https://gitlab.com/',
+        'Description' => "Some mostly empty lib\nUsed in GitLab tests.\n\nTesting another paragraph."
       }
 
       expect(subject.execute).to eq expected

spec/services/packages/debian/extract_metadata_service_spec.rb

@@ -33,11 +33,11 @@ RSpec.describe Packages::Debian::ExtractMetadataService do
   where(:case_name, :trait, :expected_file_type, :expected_architecture, :expected_fields) do
     'with invalid'    | :invalid   | :unknown   | nil     | nil
     'with source'     | :source    | :source    | nil     | nil
-    'with dsc'        | :dsc       | :dsc       | nil     | { 'Binary': 'sample-dev, libsample0, sample-udeb' }
-    'with deb'        | :deb       | :deb       | 'amd64' | { 'Multi-Arch': 'same' }
-    'with udeb'       | :udeb      | :udeb      | 'amd64' | { 'Package': 'sample-udeb' }
-    'with buildinfo'  | :buildinfo | :buildinfo | nil     | { 'Architecture': 'amd64 source', 'Build-Architecture': 'amd64' }
-    'with changes'    | :changes   | :changes   | nil     | { 'Architecture': 'source amd64', 'Binary': 'libsample0 sample-dev sample-udeb' }
+    'with dsc'        | :dsc       | :dsc       | nil     | { 'Binary' => 'sample-dev, libsample0, sample-udeb' }
+    'with deb'        | :deb       | :deb       | 'amd64' | { 'Multi-Arch' => 'same' }
+    'with udeb'       | :udeb      | :udeb      | 'amd64' | { 'Package' => 'sample-udeb' }
+    'with buildinfo'  | :buildinfo | :buildinfo | nil     | { 'Architecture' => 'amd64 source', 'Build-Architecture' => 'amd64' }
+    'with changes'    | :changes   | :changes   | nil     | { 'Architecture' => 'source amd64', 'Binary' => 'libsample0 sample-dev sample-udeb' }
   end
 
   with_them do

spec/services/packages/debian/parse_debian822_service_spec.rb

@@ -27,17 +27,17 @@ RSpec.describe Packages::Debian::ParseDebian822Service do
     it 'return as expected, preserving order' do
       expected = {
         'Package: libsample0' => {
-          'Package': 'libsample0',
-          'Source': 'sample',
-          'Version': '1.2.3~alpha2',
-          'Architecture': 'amd64',
-          'Maintainer': 'John Doe <john.doe@example.com>',
-          'Installed-Size': '9',
-          'Section': 'libs',
-          'Priority': 'optional',
-          'Multi-Arch': 'same',
-          'Homepage': 'https://gitlab.com/',
-          'Description': "Some mostly empty lib\nUsed in GitLab tests.\n\nTesting another paragraph."
+          'Package' => 'libsample0',
+          'Source' => 'sample',
+          'Version' => '1.2.3~alpha2',
+          'Architecture' => 'amd64',
+          'Maintainer' => 'John Doe <john.doe@example.com>',
+          'Installed-Size' => '9',
+          'Section' => 'libs',
+          'Priority' => 'optional',
+          'Multi-Arch' => 'same',
+          'Homepage' => 'https://gitlab.com/',
+          'Description' => "Some mostly empty lib\nUsed in GitLab tests.\n\nTesting another paragraph."
         }
       }
 
@@ -51,38 +51,38 @@ RSpec.describe Packages::Debian::ParseDebian822Service do
     it 'return as expected, preserving order' do
       expected = {
         'Source: sample' => {
-          'Source': 'sample',
-          'Priority': 'optional',
-          'Maintainer': 'John Doe <john.doe@example.com>',
-          'Build-Depends': 'debhelper-compat (= 13)',
-          'Standards-Version': '4.5.0',
-          'Section': 'libs',
-          'Homepage': 'https://gitlab.com/',
-          # 'Vcs-Browser': 'https://salsa.debian.org/debian/sample-1.2.3',
-          # '#Vcs-Git': 'https://salsa.debian.org/debian/sample-1.2.3.git',
-          'Rules-Requires-Root': 'no'
+          'Source' => 'sample',
+          'Priority' => 'optional',
+          'Maintainer' => 'John Doe <john.doe@example.com>',
+          'Build-Depends' => 'debhelper-compat (= 13)',
+          'Standards-Version' => '4.5.0',
+          'Section' => 'libs',
+          'Homepage' => 'https://gitlab.com/',
+          # 'Vcs-Browser' => 'https://salsa.debian.org/debian/sample-1.2.3',
+          # '#Vcs-Git' => 'https://salsa.debian.org/debian/sample-1.2.3.git',
+          'Rules-Requires-Root' => 'no'
         },
         'Package: sample-dev' => {
-          'Package': 'sample-dev',
-          'Section': 'libdevel',
-          'Architecture': 'any',
-          'Multi-Arch': 'same',
-          'Depends': 'libsample0 (= ${binary:Version}), ${misc:Depends}',
-          'Description': "Some mostly empty developpement files\nUsed in GitLab tests.\n\nTesting another paragraph."
+          'Package' => 'sample-dev',
+          'Section' => 'libdevel',
+          'Architecture' => 'any',
+          'Multi-Arch' => 'same',
+          'Depends' => 'libsample0 (= ${binary:Version}), ${misc:Depends}',
+          'Description' => "Some mostly empty developpement files\nUsed in GitLab tests.\n\nTesting another paragraph."
         },
         'Package: libsample0' => {
-          'Package': 'libsample0',
-          'Architecture': 'any',
-          'Multi-Arch': 'same',
-          'Depends': '${shlibs:Depends}, ${misc:Depends}',
-          'Description': "Some mostly empty lib\nUsed in GitLab tests.\n\nTesting another paragraph."
+          'Package' => 'libsample0',
+          'Architecture' => 'any',
+          'Multi-Arch' => 'same',
+          'Depends' => '${shlibs:Depends}, ${misc:Depends}',
+          'Description' => "Some mostly empty lib\nUsed in GitLab tests.\n\nTesting another paragraph."
          },
          'Package: sample-udeb' => {
-           'Package': 'sample-udeb',
-           'Package-Type': 'udeb',
-           'Architecture': 'any',
-           'Depends': 'installed-base',
-           'Description': 'Some mostly empty udeb'
+           'Package' => 'sample-udeb',
+           'Package-Type' => 'udeb',
+           'Architecture' => 'any',
+           'Depends' => 'installed-base',
+           'Description' => 'Some mostly empty udeb'
          }
       }