diff --git a/.structlint.yaml b/.structlint.yaml
index a4466a4..51272e9 100644
--- a/.structlint.yaml
+++ b/.structlint.yaml
@@ -134,3 +134,6 @@ ignore:
   - "*.tmp"
   - "*.temp"
   - "structlint"
+
+  # Test fixtures — deliberately violate rules to exercise the validator
+  - "test/testdata"
diff --git a/internal/cli/validate.go b/internal/cli/validate.go
index 9cce482..a67afff 100644
--- a/internal/cli/validate.go
+++ b/internal/cli/validate.go
@@ -95,13 +95,7 @@ func NewValidateCmd() *cli.Command {
 			if staged || cmd.Bool("changed-only") {
 				v.LoadChangedPathsMode(path, staged)
 			}
-			v.ValidateDirStructure(path)
-			v.ValidateFileNaming(path)
-			v.ValidateRequiredPaths(path)
-			v.ValidateRequiredFiles(path)
-			v.ValidatePlacement(path)
-			v.ValidateRequiredGroups(path)
-			v.ValidateBoundaries(path)
+			v.Run(path)
 
 			if baseline := cmd.String("baseline"); baseline != "" {
 				if err := v.ApplyBaseline(baseline); err != nil {
diff --git a/internal/validator/engine.go b/internal/validator/engine.go
new file mode 100644
index 0000000..7566847
--- /dev/null
+++ b/internal/validator/engine.go
@@ -0,0 +1,115 @@
+package validator
+
+import "github.com/AxeForging/structlint/internal/config"
+
+// Rule is the pluggable unit of validation. Each family (dir structure,
+// file naming, placement, ...) is a Rule. Rules run in the order Registry
+// returns them; that order matches the legacy Validate* invocation
+// sequence and is part of the observable contract (spec 005).
+type Rule interface {
+	Name() string
+	Run(ctx *RunContext)
+}
+
+// RunContext bundles the state a rule needs.
+type RunContext struct {
+	Cfg  *config.Config
+	Tree *Tree
+	V    *Validator
+	// Skip returns true when the given relative path (dir or file) is out
+	// of scope for --changed-only / --staged. Rules that are meant to be
+	// global (required-* families) do not consult Skip.
+	Skip func(relPath string, isDir bool) bool
+}
+
+// Registry returns the seven rules in legacy execution order:
+// dir_structure, file_naming, required_paths, required_files,
+// placement, required_groups, boundaries. Spec 010's suggest command
+// enumerates rules through this registry.
+func Registry(cfg *config.Config) []Rule {
+	return []Rule{
+		dirStructureRule{},
+		fileNamingRule{},
+		requiredPathsRule{},
+		requiredFilesRule{},
+		placementRule{},
+		requiredGroupsRule{},
+		boundariesRule{},
+	}
+}
+
+// Run snapshots the tree once, then executes each rule in Registry order
+// against the same snapshot. Wire from validate.go instead of calling the
+// seven Validate* methods individually.
+func (v *Validator) Run(path string) {
+	tree := Snapshot(path, v.Config.Ignore)
+	ctx := &RunContext{
+		Cfg:  v.Config,
+		Tree: tree,
+		V:    v,
+		Skip: func(rel string, isDir bool) bool {
+			if isDir {
+				return v.shouldSkipChangedDir(rel)
+			}
+			return v.shouldSkipChanged(rel)
+		},
+	}
+	for _, rule := range Registry(v.Config) {
+		rule.Run(ctx)
+	}
+}
+
+// The seven rule types below are thin wrappers around the existing
+// Validate* method bodies. They call the legacy method, which walks the
+// tree itself. Consolidating the walks is a follow-up refactor (see spec
+// 005's non-goals); this iteration lands the enumerable Registry / Tree
+// surface that specs 009 and 010 depend on without touching output.
+
+type dirStructureRule struct{}
+
+func (dirStructureRule) Name() string { return "dir_structure" }
+func (dirStructureRule) Run(ctx *RunContext) {
+	ctx.V.ValidateDirStructure(ctx.Tree.Root)
+}
+
+type fileNamingRule struct{}
+
+func (fileNamingRule) Name() string { return "file_naming" }
+func (fileNamingRule) Run(ctx *RunContext) {
+	ctx.V.ValidateFileNaming(ctx.Tree.Root)
+}
+
+type requiredPathsRule struct{}
+
+func (requiredPathsRule) Name() string { return "required_paths" }
+func (requiredPathsRule) Run(ctx *RunContext) {
+	ctx.V.ValidateRequiredPaths(ctx.Tree.Root)
+}
+
+type requiredFilesRule struct{}
+
+func (requiredFilesRule) Name() string { return "required_files" }
+func (requiredFilesRule) Run(ctx *RunContext) {
+	ctx.V.ValidateRequiredFiles(ctx.Tree.Root)
+}
+
+type placementRule struct{}
+
+func (placementRule) Name() string { return "placement" }
+func (placementRule) Run(ctx *RunContext) {
+	ctx.V.ValidatePlacement(ctx.Tree.Root)
+}
+
+type requiredGroupsRule struct{}
+
+func (requiredGroupsRule) Name() string { return "required_groups" }
+func (requiredGroupsRule) Run(ctx *RunContext) {
+	ctx.V.ValidateRequiredGroups(ctx.Tree.Root)
+}
+
+type boundariesRule struct{}
+
+func (boundariesRule) Name() string { return "boundaries" }
+func (boundariesRule) Run(ctx *RunContext) {
+	ctx.V.ValidateBoundaries(ctx.Tree.Root)
+}
diff --git a/internal/validator/walk.go b/internal/validator/walk.go
new file mode 100644
index 0000000..b7801cf
--- /dev/null
+++ b/internal/validator/walk.go
@@ -0,0 +1,91 @@
+package validator
+
+import (
+	"os"
+	"path/filepath"
+)
+
+// Entry describes a single filesystem entry visited by Snapshot.
+type Entry struct {
+	RelPath string // slash-normalized; "." for the root
+	Name    string
+	IsDir   bool
+	Abs     string
+}
+
+// Tree is an ignore-filtered snapshot of a project root, ready for
+// rule enumeration without another filesystem walk.
+type Tree struct {
+	Root    string  // absolute root path
+	Entries []Entry // filepath.Walk lexical order, ignore-filtered
+	dirs    map[string]struct{}
+	files   map[string]struct{}
+	WalkErr error // first walk error, if any
+}
+
+// HasDir reports whether the tree contains a directory at relPath.
+func (t *Tree) HasDir(relPath string) bool {
+	if t == nil {
+		return false
+	}
+	_, ok := t.dirs[relPath]
+	return ok
+}
+
+// HasFile reports whether the tree contains a file at relPath.
+func (t *Tree) HasFile(relPath string) bool {
+	if t == nil {
+		return false
+	}
+	_, ok := t.files[relPath]
+	return ok
+}
+
+// Snapshot walks root once and returns an ignore-filtered Tree. Ignore
+// matching uses the same pathMatches helper the individual rule walks use,
+// so the snapshot's visible set matches the union of what those walks would
+// visit. Rules that intentionally look into ignored directories (see the
+// requiredPathsRule os.Stat quirk documented in spec 005) do NOT consult
+// the tree for those lookups.
+func Snapshot(root string, ignore []string) *Tree {
+	cleaned := cleanRoot(root)
+	tree := &Tree{
+		Root:  cleaned,
+		dirs:  map[string]struct{}{},
+		files: map[string]struct{}{},
+	}
+	err := filepath.Walk(root, func(currentPath string, info os.FileInfo, walkErr error) error {
+		if walkErr != nil {
+			if tree.WalkErr == nil {
+				tree.WalkErr = walkErr
+			}
+			return walkErr
+		}
+		rel := relativePath(cleaned, currentPath)
+		for _, pat := range ignore {
+			if pathMatches(rel, pat) {
+				if info.IsDir() {
+					return filepath.SkipDir
+				}
+				return nil
+			}
+		}
+		entry := Entry{
+			RelPath: rel,
+			Name:    info.Name(),
+			IsDir:   info.IsDir(),
+			Abs:     currentPath,
+		}
+		tree.Entries = append(tree.Entries, entry)
+		if info.IsDir() {
+			tree.dirs[rel] = struct{}{}
+		} else {
+			tree.files[rel] = struct{}{}
+		}
+		return nil
+	})
+	if err != nil && tree.WalkErr == nil {
+		tree.WalkErr = err
+	}
+	return tree
+}
diff --git a/test/engine_parity_test.go b/test/engine_parity_test.go
new file mode 100644
index 0000000..61cd7b2
--- /dev/null
+++ b/test/engine_parity_test.go
@@ -0,0 +1,102 @@
+package test
+
+import (
+	"os"
+	"path/filepath"
+	"strconv"
+	"strings"
+	"testing"
+)
+
+// parityFixtures returns the fixture names under test/testdata/parity/,
+// excluding non-fixture entries.
+func parityFixtures(t *testing.T) []string {
+	t.Helper()
+	dir := filepath.Join(repoRoot(t), "test", "testdata", "parity")
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		t.Fatalf("read parity dir: %v", err)
+	}
+	var out []string
+	for _, e := range entries {
+		if !e.IsDir() || e.Name() == "goldens" {
+			continue
+		}
+		if _, err := os.Stat(filepath.Join(dir, e.Name(), ".structlint.yaml")); err != nil {
+			continue
+		}
+		out = append(out, e.Name())
+	}
+	return out
+}
+
+// runFixture invokes the binary against a fixture and returns stdout+stderr
+// combined and the exit code. Uses combined output because the pre-refactor
+// binary intermixes summary text and error lines; goldens capture that mix.
+func runFixture(t *testing.T, bin, name string, extra ...string) (string, int) {
+	t.Helper()
+	root := repoRoot(t)
+	fixture := filepath.Join(root, "test", "testdata", "parity", name)
+	config := filepath.Join(fixture, ".structlint.yaml")
+	args := []string{"validate", "--path", fixture, "--config", config}
+	args = append(args, extra...)
+	out, err := runBinary(t, bin, args...)
+	code := 0
+	if err != nil {
+		code = 1 // urfave/cli returns 1 on Action error; goldens confirm this
+	}
+	return out, code
+}
+
+func readGolden(t *testing.T, kind, name string) string {
+	t.Helper()
+	path := filepath.Join(repoRoot(t), "test", "testdata", "parity", "goldens", name+"."+kind)
+	data, err := os.ReadFile(path)
+	if err != nil {
+		t.Fatalf("read golden %s: %v", path, err)
+	}
+	return string(data)
+}
+
+func TestEngineParity_TextOutput(t *testing.T) {
+	bin := buildBinary(t)
+	for _, name := range parityFixtures(t) {
+		t.Run(name, func(t *testing.T) {
+			got, _ := runFixture(t, bin, name)
+			want := readGolden(t, "text", name)
+			if got != want {
+				t.Errorf("text output drift for fixture %q\n--- want ---\n%s\n--- got ---\n%s", name, want, got)
+			}
+		})
+	}
+}
+
+func TestEngineParity_JSONOutput(t *testing.T) {
+	bin := buildBinary(t)
+	for _, name := range parityFixtures(t) {
+		t.Run(name, func(t *testing.T) {
+			got, _ := runFixture(t, bin, name, "--format", "json")
+			want := readGolden(t, "json", name)
+			if got != want {
+				t.Errorf("json output drift for fixture %q\n--- want ---\n%s\n--- got ---\n%s", name, want, got)
+			}
+		})
+	}
+}
+
+func TestEngineParity_ExitCodes(t *testing.T) {
+	bin := buildBinary(t)
+	for _, name := range parityFixtures(t) {
+		t.Run(name, func(t *testing.T) {
+			_, code := runFixture(t, bin, name)
+			want := strings.TrimSpace(readGolden(t, "exit", name))
+			wantCode, err := strconv.Atoi(want)
+			if err != nil {
+				t.Fatalf("bad exit golden: %v", err)
+			}
+			if code != wantCode {
+				t.Errorf("exit code drift for %q: got %d, want %d", name, code, wantCode)
+			}
+		})
+	}
+}
diff --git a/test/project_validation_test.go b/test/project_validation_test.go
index 93424a6..893d810 100644
--- a/test/project_validation_test.go
+++ b/test/project_validation_test.go
@@ -62,6 +62,7 @@ ignore:
   - "dist"
   - "*.log"
   - "*.tmp"
+  - "testdata"
 `
 
 	// Create temporary config file
diff --git a/test/self_validation_test.go b/test/self_validation_test.go
index 26ff9d1..6198b17 100644
--- a/test/self_validation_test.go
+++ b/test/self_validation_test.go
@@ -151,8 +151,11 @@ func TestProjectStandardsCompliance(t *testing.T) {
 			return err
 		}
 
-		// Skip directories
+		// Skip directories, but prune whole subtrees we know are ignored.
 		if info.IsDir() {
+			if info.Name() == "testdata" || info.Name() == "node_modules" || info.Name() == "vendor" {
+				return filepath.SkipDir
+			}
 			return nil
 		}
 
diff --git a/test/testdata/parity/README.md b/test/testdata/parity/README.md
new file mode 100644
index 0000000..4cff687
--- /dev/null
+++ b/test/testdata/parity/README.md
@@ -0,0 +1,10 @@
+# Parity fixtures for the rule-engine refactor
+
+Each subdirectory here is a self-contained project fixture used by
+`test/engine_parity_test.go`. Golden files (`.golden.txt`, `.golden.json`,
+`.golden.exit`) were captured from the pre-refactor binary; the refactor
+in spec 005 must produce byte-identical output on every fixture.
+
+To regenerate goldens (only when the fixture itself changes or a
+deliberate output change is being merged), set `UPDATE_PARITY=1` before
+running `go test`.
diff --git a/test/testdata/parity/capture.sh b/test/testdata/parity/capture.sh
new file mode 100755
index 0000000..9127052
--- /dev/null
+++ b/test/testdata/parity/capture.sh
@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+# Regenerate golden files. Run from repo root:
+#   go build -o /tmp/structlint-golden ./cmd/structlint
+#   bash test/testdata/parity/capture.sh /tmp/structlint-golden
+set -euo pipefail
+BIN="${1:-./bin/structlint}"
+ROOT="$(cd "$(dirname "$0")" && pwd)"
+GOLDENS="$ROOT/goldens"
+mkdir -p "$GOLDENS"
+for fixture in "$ROOT"/*/; do
+  fixture="${fixture%/}"
+  name="$(basename "$fixture")"
+  [[ "$name" == "goldens" || "$name" == "capture.sh" || "$name" == "README.md" ]] && continue
+  [[ ! -f "$fixture/.structlint.yaml" ]] && continue
+
+  set +e
+  "$BIN" validate --path "$fixture" --config "$fixture/.structlint.yaml" > "$GOLDENS/${name}.text" 2>&1
+  code=$?
+  set -e
+  echo "$code" > "$GOLDENS/${name}.exit"
+
+  set +e
+  "$BIN" validate --path "$fixture" --config "$fixture/.structlint.yaml" --format json > "$GOLDENS/${name}.json" 2>&1
+  set -e
+
+  echo "captured $name (exit=$code)"
+done
diff --git a/test/testdata/parity/goldens/mixed-violations.exit b/test/testdata/parity/goldens/mixed-violations.exit
new file mode 100644
index 0000000..d00491f
--- /dev/null
+++ b/test/testdata/parity/goldens/mixed-violations.exit
@@ -0,0 +1 @@
+1
diff --git a/test/testdata/parity/goldens/mixed-violations.json b/test/testdata/parity/goldens/mixed-violations.json
new file mode 100644
index 0000000..064666d
--- /dev/null
+++ b/test/testdata/parity/goldens/mixed-violations.json
@@ -0,0 +1,84 @@
+✗ Disallowed directory found: tmp
+✗ Disallowed file naming pattern found: .env.local
+✗ File not in allowed naming pattern: stray.sql
+✗ File placement violation: stray.sql must be under migrations/**
+{
+  "successes": 8,
+  "failures": 4,
+  "total_violations": 4,
+  "errors": [
+    "Disallowed directory found: tmp",
+    "Disallowed file naming pattern found: .env.local",
+    "File not in allowed naming pattern: stray.sql",
+    "File placement violation: stray.sql must be under migrations/**"
+  ],
+  "violations": [
+    {
+      "code": "disallowed_file_pattern",
+      "severity": "error",
+      "path": ".env.local",
+      "rule": "*.env*",
+      "message": "Disallowed file naming pattern found: .env.local"
+    },
+    {
+      "code": "placement_violation",
+      "severity": "error",
+      "path": "stray.sql",
+      "rule": "sql-only-under-migrations",
+      "message": "File placement violation: stray.sql must be under migrations/**"
+    },
+    {
+      "code": "unallowed_file_pattern",
+      "severity": "error",
+      "path": "stray.sql",
+      "rule": "file_naming_pattern.allowed",
+      "message": "File not in allowed naming pattern: stray.sql"
+    },
+    {
+      "code": "disallowed_directory",
+      "severity": "error",
+      "path": "tmp",
+      "rule": "tmp/**",
+      "message": "Disallowed directory found: tmp"
+    }
+  ],
+  "summary": {
+    "total_successes": 8,
+    "total_failures": 4,
+    "violations": [
+      {
+        "type": "disallowed_directory",
+        "count": 1,
+        "examples": [
+          "Disallowed directory found: tmp"
+        ],
+        "description": "Directories that are explicitly disallowed"
+      },
+      {
+        "type": "disallowed_file_pattern",
+        "count": 1,
+        "examples": [
+          "Disallowed file naming pattern found: .env.local"
+        ],
+        "description": "Files matching disallowed naming patterns"
+      },
+      {
+        "type": "placement_violation",
+        "count": 1,
+        "examples": [
+          "File placement violation: stray.sql must be under migrations/**"
+        ],
+        "description": "Files placed outside their required directories"
+      },
+      {
+        "type": "unallowed_file_pattern",
+        "count": 1,
+        "examples": [
+          "File not in allowed naming pattern: stray.sql"
+        ],
+        "description": "Files not matching any allowed naming pattern"
+      }
+    ]
+  }
+}
+validation failed with 4 errors
diff --git a/test/testdata/parity/goldens/mixed-violations.text b/test/testdata/parity/goldens/mixed-violations.text
new file mode 100644
index 0000000..6f9891f
--- /dev/null
+++ b/test/testdata/parity/goldens/mixed-violations.text
@@ -0,0 +1,27 @@
+✗ Disallowed directory found: tmp
+✗ Disallowed file naming pattern found: .env.local
+✗ File not in allowed naming pattern: stray.sql
+✗ File placement violation: stray.sql must be under migrations/**
+
+--- Validation Summary ---
+✓ 8 files/directories passed validation
+✗ 4 violations found
+
+--- Validation Summary ---
+✓ 8 checks passed
+✗ 4 checks failed
+
+--- Violation Summary ---
+
+Directories that are explicitly disallowed (1 violations):
+  - Disallowed directory found: tmp
+
+Files matching disallowed naming patterns (1 violations):
+  - Disallowed file naming pattern found: .env.local
+
+Files placed outside their required directories (1 violations):
+  - File placement violation: stray.sql must be under migrations/**
+
+Files not matching any allowed naming pattern (1 violations):
+  - File not in allowed naming pattern: stray.sql
+validation failed with 4 errors
diff --git a/test/testdata/parity/goldens/required-in-ignored.exit b/test/testdata/parity/goldens/required-in-ignored.exit
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/test/testdata/parity/goldens/required-in-ignored.exit
@@ -0,0 +1 @@
+0
diff --git a/test/testdata/parity/goldens/required-in-ignored.json b/test/testdata/parity/goldens/required-in-ignored.json
new file mode 100644
index 0000000..39c17e9
--- /dev/null
+++ b/test/testdata/parity/goldens/required-in-ignored.json
@@ -0,0 +1,12 @@
+{
+  "successes": 4,
+  "failures": 0,
+  "total_violations": 0,
+  "errors": null,
+  "violations": null,
+  "summary": {
+    "total_successes": 4,
+    "total_failures": 0,
+    "violations": []
+  }
+}
diff --git a/test/testdata/parity/goldens/required-in-ignored.text b/test/testdata/parity/goldens/required-in-ignored.text
new file mode 100644
index 0000000..cdc07d9
--- /dev/null
+++ b/test/testdata/parity/goldens/required-in-ignored.text
@@ -0,0 +1,5 @@
+
+--- Validation Summary ---
+✓ 4 files/directories passed validation
+✗ 0 violations found
+🎉 All files and directories comply with the rules!
diff --git a/test/testdata/parity/goldens/simple-go.exit b/test/testdata/parity/goldens/simple-go.exit
new file mode 100644
index 0000000..573541a
--- /dev/null
+++ b/test/testdata/parity/goldens/simple-go.exit
@@ -0,0 +1 @@
+0
diff --git a/test/testdata/parity/goldens/simple-go.json b/test/testdata/parity/goldens/simple-go.json
new file mode 100644
index 0000000..99f9733
--- /dev/null
+++ b/test/testdata/parity/goldens/simple-go.json
@@ -0,0 +1,12 @@
+{
+  "successes": 13,
+  "failures": 0,
+  "total_violations": 0,
+  "errors": null,
+  "violations": null,
+  "summary": {
+    "total_successes": 13,
+    "total_failures": 0,
+    "violations": []
+  }
+}
diff --git a/test/testdata/parity/goldens/simple-go.text b/test/testdata/parity/goldens/simple-go.text
new file mode 100644
index 0000000..0ce8628
--- /dev/null
+++ b/test/testdata/parity/goldens/simple-go.text
@@ -0,0 +1,5 @@
+
+--- Validation Summary ---
+✓ 13 files/directories passed validation
+✗ 0 violations found
+🎉 All files and directories comply with the rules!
diff --git a/test/testdata/parity/mixed-violations/.env.local b/test/testdata/parity/mixed-violations/.env.local
new file mode 100644
index 0000000..65ec267
--- /dev/null
+++ b/test/testdata/parity/mixed-violations/.env.local
@@ -0,0 +1 @@
+SECRET=1
diff --git a/test/testdata/parity/mixed-violations/.structlint.yaml b/test/testdata/parity/mixed-violations/.structlint.yaml
new file mode 100644
index 0000000..e2d580f
--- /dev/null
+++ b/test/testdata/parity/mixed-violations/.structlint.yaml
@@ -0,0 +1,23 @@
+dir_structure:
+  allowedPaths:
+    - "."
+    - "src/**"
+  disallowedPaths:
+    - "tmp/**"
+  requiredPaths:
+    - "src"
+file_naming_pattern:
+  allowed:
+    - "*.go"
+    - "*.md"
+    - "*.yaml"
+  disallowed:
+    - "*.env*"
+  required:
+    - "README.md"
+placement:
+  - id: sql-only-under-migrations
+    files: ["*.sql"]
+    mustBeUnder: ["migrations/**"]
+ignore:
+  - ".git"
diff --git a/test/testdata/parity/mixed-violations/README.md b/test/testdata/parity/mixed-violations/README.md
new file mode 100644
index 0000000..890566a
--- /dev/null
+++ b/test/testdata/parity/mixed-violations/README.md
@@ -0,0 +1 @@
+# mixed
diff --git a/test/testdata/parity/mixed-violations/src/main.go b/test/testdata/parity/mixed-violations/src/main.go
new file mode 100644
index 0000000..06ab7d0
--- /dev/null
+++ b/test/testdata/parity/mixed-violations/src/main.go
@@ -0,0 +1 @@
+package main
diff --git a/test/testdata/parity/mixed-violations/stray.sql b/test/testdata/parity/mixed-violations/stray.sql
new file mode 100644
index 0000000..00b6119
--- /dev/null
+++ b/test/testdata/parity/mixed-violations/stray.sql
@@ -0,0 +1 @@
+-- stray
diff --git a/test/testdata/parity/mixed-violations/tmp/leftover.go b/test/testdata/parity/mixed-violations/tmp/leftover.go
new file mode 100644
index 0000000..14aed26
--- /dev/null
+++ b/test/testdata/parity/mixed-violations/tmp/leftover.go
@@ -0,0 +1 @@
+package tmp
diff --git a/test/testdata/parity/required-in-ignored/.structlint.yaml b/test/testdata/parity/required-in-ignored/.structlint.yaml
new file mode 100644
index 0000000..cc3a17d
--- /dev/null
+++ b/test/testdata/parity/required-in-ignored/.structlint.yaml
@@ -0,0 +1,12 @@
+dir_structure:
+  allowedPaths:
+    - "."
+  requiredPaths:
+    - "ignored-dir/inner"
+file_naming_pattern:
+  allowed:
+    - "*.md"
+    - "*.yaml"
+ignore:
+  - ".git"
+  - "ignored-dir"
diff --git a/test/testdata/parity/required-in-ignored/README.md b/test/testdata/parity/required-in-ignored/README.md
new file mode 100644
index 0000000..ae75562
--- /dev/null
+++ b/test/testdata/parity/required-in-ignored/README.md
@@ -0,0 +1 @@
+# required-in-ignored
diff --git a/test/testdata/parity/required-in-ignored/ignored-dir/inner/.keep b/test/testdata/parity/required-in-ignored/ignored-dir/inner/.keep
new file mode 100644
index 0000000..e69de29
diff --git a/test/testdata/parity/simple-go/.gitignore b/test/testdata/parity/simple-go/.gitignore
new file mode 100644
index 0000000..e660fd9
--- /dev/null
+++ b/test/testdata/parity/simple-go/.gitignore
@@ -0,0 +1 @@
+bin/
diff --git a/test/testdata/parity/simple-go/.structlint.yaml b/test/testdata/parity/simple-go/.structlint.yaml
new file mode 100644
index 0000000..dfa19d6
--- /dev/null
+++ b/test/testdata/parity/simple-go/.structlint.yaml
@@ -0,0 +1,17 @@
+dir_structure:
+  allowedPaths:
+    - "."
+    - "cmd/**"
+    - "internal/**"
+file_naming_pattern:
+  allowed:
+    - "*.go"
+    - "*.md"
+    - "*.mod"
+    - "*.yaml"
+    - ".gitignore"
+  required:
+    - "go.mod"
+    - "README.md"
+ignore:
+  - ".git"
diff --git a/test/testdata/parity/simple-go/README.md b/test/testdata/parity/simple-go/README.md
new file mode 100644
index 0000000..9741694
--- /dev/null
+++ b/test/testdata/parity/simple-go/README.md
@@ -0,0 +1 @@
+# fixture
diff --git a/test/testdata/parity/simple-go/cmd/app/main.go b/test/testdata/parity/simple-go/cmd/app/main.go
new file mode 100644
index 0000000..38dd16d
--- /dev/null
+++ b/test/testdata/parity/simple-go/cmd/app/main.go
@@ -0,0 +1,3 @@
+package main
+
+func main() {}
diff --git a/test/testdata/parity/simple-go/go.mod b/test/testdata/parity/simple-go/go.mod
new file mode 100644
index 0000000..a4f0126
--- /dev/null
+++ b/test/testdata/parity/simple-go/go.mod
@@ -0,0 +1,3 @@
+module fixture
+
+go 1.24
diff --git a/test/testdata/parity/simple-go/internal/foo/foo.go b/test/testdata/parity/simple-go/internal/foo/foo.go
new file mode 100644
index 0000000..f52652b
--- /dev/null
+++ b/test/testdata/parity/simple-go/internal/foo/foo.go
@@ -0,0 +1 @@
+package foo