fix(babel): normalize resolved paths to POSIX so Windows rewrites work

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"]);
+  });
+});

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, "/");
+}

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) {

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) {