From 0f723921229eedf20a6767c65c6bec77d705ddec Mon Sep 17 00:00:00 2001
From: Yevhenii <evgeny.kotyrlo@gmail.com>
Date: Thu, 23 Jul 2026 19:09:06 +0300
Subject: [PATCH] fix(babel): normalize resolved paths to POSIX so Windows
 rewrites work

The import plugin's relative-import handlers resolve a source against the file
being transformed and then match the result against forward-slash literals
(`react-native/Libraries/Components/`, `react-native-web/dist`). path.resolve
returns backslash-separated paths on Windows, so those splits never match and
the import is left un-rewritten. Only relative imports break, and only on
Windows -- bare specifiers are plain string matches; the failing cases were
green on the Linux/macOS CI.

Add a `resolvePosix` helper (resolve + normalize \ -> /) and use it in
parseReactNativeSource / parseReactNativeWebSource. Resolve semantics are
unchanged; only the separator is normalized. import-plugin's isFromThisModule
stays on path.resolve -- it compares two OS-native paths, so it already works.

Adds a helpers unit test asserting the POSIX invariant.
---
 src/__tests__/babel/helpers.test.ts | 20 ++++++++++++++++++++
 src/babel/helpers.ts                | 16 ++++++++++++++++
 src/babel/react-native-web.ts       |  5 ++---
 src/babel/react-native.ts           |  5 +++--
 4 files changed, 41 insertions(+), 5 deletions(-)
 create mode 100644 src/__tests__/babel/helpers.test.ts

diff --git a/src/__tests__/babel/helpers.test.ts b/src/__tests__/babel/helpers.test.ts
new file mode 100644
index 00000000..d0520a14
--- /dev/null
+++ b/src/__tests__/babel/helpers.test.ts
@@ -0,0 +1,20 @@
+import { resolvePosix } from "../../babel/helpers";
+
+describe("resolvePosix", () => {
+  test("resolves to an absolute path with POSIX separators on every platform", () => {
+    // The invariant the import handlers depend on: no backslashes leak through,
+    // so their forward-slash `split` / `startsWith` matching works on Windows
+    // (where path.resolve otherwise yields "\"-separated paths).
+    const result = resolvePosix(process.cwd(), "a", "b", "c");
+
+    expect(result).not.toContain("\\");
+    expect(result.split("/").slice(-3)).toEqual(["a", "b", "c"]);
+  });
+
+  test("collapses '..' segments like path.resolve, keeping POSIX separators", () => {
+    const result = resolvePosix(process.cwd(), "a", "b", "..", "c");
+
+    expect(result).not.toContain("\\");
+    expect(result.split("/").slice(-2)).toEqual(["a", "c"]);
+  });
+});
diff --git a/src/babel/helpers.ts b/src/babel/helpers.ts
index c66f630c..9a08e5d0 100644
--- a/src/babel/helpers.ts
+++ b/src/babel/helpers.ts
@@ -1,3 +1,5 @@
+import { resolve } from "path";
+
 import tBabelTypes, { type CallExpression } from "@babel/types";
 
 export type BabelTypes = typeof tBabelTypes;
@@ -38,3 +40,17 @@ export function getInteropRequireDefaultSource(
 
   return requireArg.value;
 }
+
+/**
+ * `path.resolve`, normalized to POSIX separators.
+ *
+ * The relative-import handlers resolve a source against the file being
+ * transformed and then match the result against forward-slash literals
+ * (`react-native/Libraries/Components/`, `react-native-web/dist`, …). On Windows
+ * `path.resolve` yields backslash separators, so those `split` / `startsWith`
+ * matches silently miss and the import is left un-rewritten. Normalizing to `/`
+ * makes the matching platform-independent.
+ */
+export function resolvePosix(...segments: string[]): string {
+  return resolve(...segments).replace(/\\/g, "/");
+}
diff --git a/src/babel/react-native-web.ts b/src/babel/react-native-web.ts
index 1bacf5a0..db860a49 100644
--- a/src/babel/react-native-web.ts
+++ b/src/babel/react-native-web.ts
@@ -1,5 +1,3 @@
-import { resolve } from "path";
-
 import { type NodePath } from "@babel/traverse";
 import tBabelTypes, {
   type ImportDeclaration,
@@ -9,12 +7,13 @@ import tBabelTypes, {
 } from "@babel/types";
 
 import { allowedModules } from "./allowedModules";
+import { resolvePosix } from "./helpers";
 
 type BabelTypes = typeof tBabelTypes;
 
 function parseReactNativeWebSource(source: string, filename: string) {
   if (source.startsWith(".")) {
-    source = resolve(filename, source);
+    source = resolvePosix(filename, source);
 
     const internalPath = source.split("react-native-web/dist")[1];
     if (!internalPath) {
diff --git a/src/babel/react-native.ts b/src/babel/react-native.ts
index 2522a848..ad65c941 100644
--- a/src/babel/react-native.ts
+++ b/src/babel/react-native.ts
@@ -1,4 +1,4 @@
-import { dirname, resolve } from "path";
+import { dirname } from "path";
 
 import { type NodePath } from "@babel/traverse";
 import tBabelTypes, {
@@ -9,12 +9,13 @@ import tBabelTypes, {
 } from "@babel/types";
 
 import { allowedModules } from "./allowedModules";
+import { resolvePosix } from "./helpers";
 
 type BabelTypes = typeof tBabelTypes;
 
 function parseReactNativeSource(source: string, filename: string) {
   if (source.startsWith(".")) {
-    source = resolve(dirname(filename), source);
+    source = resolvePosix(dirname(filename), source);
 
     const internalPath = source.split("react-native/Libraries/Components/")[1];
     if (!internalPath) {