Add test fixtures and specs for pks JSON integration

Create JSON fixture files representing pks check output for various
violation scenarios (privacy, dependency, multiple, strict mode).
Extend pks_offense_spec with fixture-based tests to verify parsing.
Add pks_wrapper_spec with test patterns ready for PksWrapper impl.

All 90 existing tests continue to pass.

Author: martinemde

spec/danger_packwerk/pks_offense_spec.rb

@@ -4,6 +4,7 @@ module DangerPackwerk
   RSpec.describe PksOffense do
     # PksOffense doesn't need Danger plugin context, but spec_helper includes it
     let(:plugin) { dangerfile.packwerk }
+    let(:fixtures_path) { File.join(__dir__, '..', 'fixtures', 'pks_output') }
     let(:privacy_offense_hash) do
       {
         'violation_type' => 'privacy',
@@ -152,5 +153,98 @@ module DangerPackwerk
         expect(hash[offense1]).to eq('second')
       end
     end
+
+    describe 'fixture-based tests' do
+      describe 'no_violations.json' do
+        let(:json) { File.read(File.join(fixtures_path, 'no_violations.json')) }
+
+        it 'parses empty offenses array' do
+          offenses = described_class.from_json(json)
+          expect(offenses).to eq([])
+        end
+      end
+
+      describe 'privacy_violation.json' do
+        let(:json) { File.read(File.join(fixtures_path, 'privacy_violation.json')) }
+
+        it 'parses a single privacy violation' do
+          offenses = described_class.from_json(json)
+
+          expect(offenses.length).to eq(1)
+          offense = offenses.first
+          expect(offense.violation_type).to eq('privacy')
+          expect(offense.file).to eq('packs/my_pack/app/models/user.rb')
+          expect(offense.line).to eq(42)
+          expect(offense.column).to eq(10)
+          expect(offense.constant_name).to eq('::OtherPack::PrivateClass')
+          expect(offense.referencing_pack_name).to eq('packs/my_pack')
+          expect(offense.defining_pack_name).to eq('packs/other_pack')
+          expect(offense.strict).to eq(false)
+          expect(offense.privacy?).to eq(true)
+          expect(offense.dependency?).to eq(false)
+        end
+      end
+
+      describe 'dependency_violation.json' do
+        let(:json) { File.read(File.join(fixtures_path, 'dependency_violation.json')) }
+
+        it 'parses a single dependency violation with strict mode' do
+          offenses = described_class.from_json(json)
+
+          expect(offenses.length).to eq(1)
+          offense = offenses.first
+          expect(offense.violation_type).to eq('dependency')
+          expect(offense.file).to eq('packs/my_pack/app/services/user_service.rb')
+          expect(offense.line).to eq(15)
+          expect(offense.column).to eq(5)
+          expect(offense.constant_name).to eq('::ThirdPack::SomeConstant')
+          expect(offense.referencing_pack_name).to eq('packs/my_pack')
+          expect(offense.defining_pack_name).to eq('packs/third_pack')
+          expect(offense.strict).to eq(true)
+          expect(offense.privacy?).to eq(false)
+          expect(offense.dependency?).to eq(true)
+        end
+      end
+
+      describe 'multiple_violations.json' do
+        let(:json) { File.read(File.join(fixtures_path, 'multiple_violations.json')) }
+
+        it 'parses multiple violations of different types' do
+          offenses = described_class.from_json(json)
+
+          expect(offenses.length).to eq(3)
+
+          privacy_offenses = offenses.select(&:privacy?)
+          dependency_offenses = offenses.select(&:dependency?)
+
+          expect(privacy_offenses.length).to eq(2)
+          expect(dependency_offenses.length).to eq(1)
+        end
+
+        it 'preserves all offense details' do
+          offenses = described_class.from_json(json)
+
+          files = offenses.map(&:file)
+          expect(files).to contain_exactly(
+            'packs/my_pack/app/models/user.rb',
+            'packs/my_pack/app/services/user_service.rb',
+            'packs/another_pack/app/models/order.rb'
+          )
+        end
+      end
+
+      describe 'strict_mode_violation.json' do
+        let(:json) { File.read(File.join(fixtures_path, 'strict_mode_violation.json')) }
+
+        it 'parses strict mode privacy violation' do
+          offenses = described_class.from_json(json)
+
+          expect(offenses.length).to eq(1)
+          offense = offenses.first
+          expect(offense.strict).to eq(true)
+          expect(offense.privacy?).to eq(true)
+        end
+      end
+    end
   end
 end

spec/fixtures/pks_output/dependency_violation.json

@@ -0,0 +1,15 @@
+{
+  "offenses": [
+    {
+      "violation_type": "dependency",
+      "file": "packs/my_pack/app/services/user_service.rb",
+      "line": 15,
+      "column": 5,
+      "constant_name": "::ThirdPack::SomeConstant",
+      "referencing_pack_name": "packs/my_pack",
+      "defining_pack_name": "packs/third_pack",
+      "strict": true,
+      "message": "Dependency violation: packs/my_pack does not declare packs/third_pack as a dependency"
+    }
+  ]
+}

spec/fixtures/pks_output/multiple_violations.json

@@ -0,0 +1,37 @@
+{
+  "offenses": [
+    {
+      "violation_type": "privacy",
+      "file": "packs/my_pack/app/models/user.rb",
+      "line": 42,
+      "column": 10,
+      "constant_name": "::OtherPack::PrivateClass",
+      "referencing_pack_name": "packs/my_pack",
+      "defining_pack_name": "packs/other_pack",
+      "strict": false,
+      "message": "Privacy violation: ::OtherPack::PrivateClass is private to packs/other_pack"
+    },
+    {
+      "violation_type": "dependency",
+      "file": "packs/my_pack/app/services/user_service.rb",
+      "line": 15,
+      "column": 5,
+      "constant_name": "::ThirdPack::SomeConstant",
+      "referencing_pack_name": "packs/my_pack",
+      "defining_pack_name": "packs/third_pack",
+      "strict": true,
+      "message": "Dependency violation: packs/my_pack does not declare packs/third_pack as a dependency"
+    },
+    {
+      "violation_type": "privacy",
+      "file": "packs/another_pack/app/models/order.rb",
+      "line": 88,
+      "column": 15,
+      "constant_name": "::OtherPack::SecretHelper",
+      "referencing_pack_name": "packs/another_pack",
+      "defining_pack_name": "packs/other_pack",
+      "strict": false,
+      "message": "Privacy violation: ::OtherPack::SecretHelper is private to packs/other_pack"
+    }
+  ]
+}

spec/fixtures/pks_output/no_violations.json

@@ -0,0 +1,3 @@
+{
+  "offenses": []
+}

spec/fixtures/pks_output/privacy_violation.json

@@ -0,0 +1,15 @@
+{
+  "offenses": [
+    {
+      "violation_type": "privacy",
+      "file": "packs/my_pack/app/models/user.rb",
+      "line": 42,
+      "column": 10,
+      "constant_name": "::OtherPack::PrivateClass",
+      "referencing_pack_name": "packs/my_pack",
+      "defining_pack_name": "packs/other_pack",
+      "strict": false,
+      "message": "Privacy violation: ::OtherPack::PrivateClass is private to packs/other_pack"
+    }
+  ]
+}

spec/fixtures/pks_output/strict_mode_violation.json

@@ -0,0 +1,15 @@
+{
+  "offenses": [
+    {
+      "violation_type": "privacy",
+      "file": "packs/strict_pack/app/services/api_client.rb",
+      "line": 23,
+      "column": 8,
+      "constant_name": "::CorePack::InternalApi",
+      "referencing_pack_name": "packs/strict_pack",
+      "defining_pack_name": "packs/core_pack",
+      "strict": true,
+      "message": "Privacy violation (strict mode): ::CorePack::InternalApi is private to packs/core_pack"
+    }
+  ]
+}