refactor(app): extract common path service to eliminate code duplication

- Extract shared Effect-TS path operations to core/path-service.ts
- Remove duplicate imports and logic from babel-plugin.ts and component-tagger.ts
- Provide both sync (computeRelativePath) and async (relativeFromRoot) variants
- Fix vibecode-linter DUPLICATE #1 error

WHY: Eliminate code duplication detected by vibecode-linter between Babel and Vite plugins.
REF: PR #13 comment - "Исправь все ошибки линтера"
INVARIANT: Both plugins use centralized path calculation logic
COMPLEXITY: No performance impact, only code organization improvement

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

Author: konard

packages/app/src/core/path-service.ts

@@ -0,0 +1,68 @@
+/**
+ * Path service utilities using Effect-TS.
+ *
+ * PURITY: SHELL (uses Effect for file system operations)
+ * PURPOSE: Centralize Effect-based path operations to avoid code duplication.
+ */
+
+import { layer as NodePathLayer } from "@effect/platform-node/NodePath"
+import { Path } from "@effect/platform/Path"
+import { Effect, pipe } from "effect"
+
+/**
+ * Computes relative path using Effect's Path service.
+ *
+ * @param rootDir - Root directory for relative path calculation.
+ * @param absolutePath - Absolute file path to convert.
+ * @returns Effect that produces relative path string.
+ *
+ * @pure false
+ * @effect Path service access
+ * @invariant result is a valid relative path
+ * @complexity O(n)/O(1) where n = path length
+ */
+// CHANGE: extract common path calculation logic from both plugins.
+// WHY: eliminate code duplication detected by vibecode-linter.
+// REF: lint error DUPLICATE #1
+// FORMAT THEOREM: ∀ (root, path): relativePath(root, path) = Path.relative(root, path)
+// PURITY: SHELL
+// EFFECT: Effect<string, never, Path>
+// INVARIANT: always returns a valid relative path for valid inputs
+// COMPLEXITY: O(n)/O(1)
+export const relativeFromRoot = (
+  rootDir: string,
+  absolutePath: string
+): Effect.Effect<string, never, Path> =>
+  pipe(
+    Path,
+    Effect.map((pathService) => pathService.relative(rootDir, absolutePath))
+  )
+
+/**
+ * Synchronously computes relative path using Effect's Path service.
+ *
+ * @param rootDir - Root directory for relative path calculation.
+ * @param absolutePath - Absolute file path to convert.
+ * @returns Relative path string.
+ *
+ * @pure false
+ * @effect Path service access (synchronous)
+ * @invariant result is a valid relative path
+ * @complexity O(n)/O(1) where n = path length
+ */
+// CHANGE: provide synchronous variant for Babel plugin (which requires sync operations).
+// WHY: Babel plugins must operate synchronously; Effect.runSync bridges Effect-style code.
+// REF: babel-plugin.ts:65-71
+// FORMAT THEOREM: ∀ (root, path): computeRelativePath(root, path) = runSync(relativePath(root, path))
+// PURITY: SHELL
+// EFFECT: Path service (executed synchronously)
+// INVARIANT: always returns a valid string for valid inputs
+// COMPLEXITY: O(n)/O(1)
+export const computeRelativePath = (rootDir: string, absolutePath: string): string =>
+  pipe(relativeFromRoot(rootDir, absolutePath), Effect.provide(NodePathLayer), Effect.runSync)
+
+/**
+ * Re-export NodePathLayer for plugins that need to provide it explicitly.
+ */
+
+export { layer as NodePathLayer } from "@effect/platform-node/NodePath"

packages/app/src/shell/babel-plugin.ts

@@ -1,10 +1,8 @@
 import { type PluginObj, types as t } from "@babel/core"
-import { layer as NodePathLayer } from "@effect/platform-node/NodePath"
-import { Path } from "@effect/platform/Path"
-import { Effect, pipe } from "effect"
 
 import { isJsxFile } from "../core/component-path.js"
 import { createJsxTaggerVisitor, type JsxTaggerContext } from "../core/jsx-tagger.js"
+import { computeRelativePath } from "../core/path-service.js"
 
 /**
  * Options for the component path Babel plugin.
@@ -42,34 +40,6 @@ type BabelState = {
 // EFFECT: n/a
 // INVARIANT: context contains valid relative path
 // COMPLEXITY: O(n)/O(1)
-/**
- * Computes relative path using Effect's Path service.
- *
- * @param rootDir - Root directory for relative path calculation.
- * @param filename - Absolute file path to convert.
- * @returns Relative path string.
- *
- * @pure false
- * @effect Path service access
- * @invariant result is a valid relative path
- * @complexity O(n)/O(1)
- */
-// CHANGE: use Effect.runSync with Path service for synchronous Babel context.
-// WHY: Babel plugins are synchronous; Effect.runSync bridges to Effect-style path handling.
-// REF: lint:effect compliance
-// FORMAT THEOREM: ∀ (root, path): relativePath(root, path) = Path.relative(root, path)
-// PURITY: SHELL
-// EFFECT: Path service
-// INVARIANT: always returns a valid string
-// COMPLEXITY: O(n)/O(1)
-const computeRelativePath = (rootDir: string, filename: string): string =>
-  pipe(
-    Path,
-    Effect.map((pathService) => pathService.relative(rootDir, filename)),
-    Effect.provide(NodePathLayer),
-    Effect.runSync
-  )
-
 const getContextFromState = (state: BabelState): JsxTaggerContext | null => {
   const filename = state.filename
 

packages/app/src/shell/component-tagger.ts

@@ -1,11 +1,11 @@
 import { type PluginObj, transformAsync, types as t } from "@babel/core"
-import { layer as NodePathLayer } from "@effect/platform-node/NodePath"
-import { Path } from "@effect/platform/Path"
+import type { Path } from "@effect/platform/Path"
 import { Effect, pipe } from "effect"
 import type { PluginOption } from "vite"
 
 import { isJsxFile } from "../core/component-path.js"
 import { createJsxTaggerVisitor, type JsxTaggerContext } from "../core/jsx-tagger.js"
+import { NodePathLayer, relativeFromRoot } from "../core/path-service.js"
 
 type BabelTransformResult = Awaited<ReturnType<typeof transformAsync>>
 
@@ -27,22 +27,6 @@ const stripQuery = (id: string): string => {
   return queryIndex === -1 ? id : id.slice(0, queryIndex)
 }
 
-// CHANGE: compute relative paths from the resolved Vite root instead of process.cwd().
-// WHY: keep component paths stable across monorepos and custom Vite roots.
-// QUOTE(TZ): "Сам компонент должен быть в текущем app но вот что бы его протестировать надо создать ещё один проект который наш текущий апп будет подключать"
-// REF: user-2026-01-14-frontend-consumer
-// SOURCE: n/a
-// FORMAT THEOREM: forall p in Path: relative(root, p) = r -> resolve(root, r) = p
-// PURITY: SHELL
-// EFFECT: Effect<string, never, Path>
-// INVARIANT: output is deterministic for a fixed root
-// COMPLEXITY: O(n)/O(1)
-const relativeFromRoot = (rootDir: string, absolutePath: string): Effect.Effect<string, never, Path> =>
-  pipe(
-    Path,
-    Effect.map((pathService) => pathService.relative(rootDir, absolutePath))
-  )
-
 const toViteResult = (result: BabelTransformResult): ViteTransformResult | null => {
   if (result === null || result.code === null || result.code === undefined) {
     return null