From 1ae5886a98a072cbb2bf7446f53c20efed9474ec Mon Sep 17 00:00:00 2001
From: morgan-coded <256248948+morgan-coded@users.noreply.github.com>
Date: Fri, 4 Sep 2026 21:21:01 -0500
Subject: [PATCH] fix: treat trailing-slash exports keys as wildcards

A "./dir/" exports key is a folder mapping equivalent to "./dir/*", so
mark it as a wildcard instead of resolving it as a literal subpath.
---
 .changeset/trailing-slash-wildcards.md        |  5 ++++
 .../core/src/internal/getEntrypointInfo.ts    |  3 +-
 packages/core/test/getEntrypointInfo.test.ts  | 29 +++++++++++++++++++
 3 files changed, 36 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/trailing-slash-wildcards.md

diff --git a/.changeset/trailing-slash-wildcards.md b/.changeset/trailing-slash-wildcards.md
new file mode 100644
index 0000000..1a2bfdf
--- /dev/null
+++ b/.changeset/trailing-slash-wildcards.md
@@ -0,0 +1,5 @@
+---
+"@arethetypeswrong/core": patch
+---
+
+Treat trailing-slash `exports` keys as wildcard entrypoints.
diff --git a/packages/core/src/internal/getEntrypointInfo.ts b/packages/core/src/internal/getEntrypointInfo.ts
index 2c33be5..54ac696 100644
--- a/packages/core/src/internal/getEntrypointInfo.ts
+++ b/packages/core/src/internal/getEntrypointInfo.ts
@@ -160,7 +160,8 @@ function getEntrypointResolution(
   resolutionKind: ResolutionKind,
   entrypoint: string,
 ): EntrypointResolutionAnalysis {
-  if (entrypoint.includes("*")) {
+  // A trailing slash is the folder-mapping form of `./dir/*`
+  if (entrypoint.includes("*") || entrypoint.endsWith("/")) {
     return { name: entrypoint, resolutionKind, isWildcard: true };
   }
   const moduleSpecifier = packageName + entrypoint.substring(1); // remove leading . before slash
diff --git a/packages/core/test/getEntrypointInfo.test.ts b/packages/core/test/getEntrypointInfo.test.ts
index 37abdac..3c03c07 100644
--- a/packages/core/test/getEntrypointInfo.test.ts
+++ b/packages/core/test/getEntrypointInfo.test.ts
@@ -34,4 +34,33 @@ describe("getEntrypointInfo", () => {
     assert("entrypoints" in result);
     assert.deepStrictEqual(Object.keys(result.entrypoints), ["./features/*.js", "./browser"]);
   });
+
+  test("treats trailing-slash exports keys as wildcards", async () => {
+    const result = await checkPackage(
+      createTestPackage({
+        "es/index.d.ts": "export {};",
+        "es/index.js": "export {};",
+        "index.d.ts": "export {};",
+        "index.js": "export {};",
+        "package.json": JSON.stringify({
+          name: "test",
+          version: "1.0.0",
+          exports: {
+            ".": "./index.js",
+            "./es/": "./es/",
+            "./es/*": "./es/*.js",
+          },
+        }),
+      }),
+    );
+
+    assert("entrypoints" in result);
+    assert.deepStrictEqual(Object.keys(result.entrypoints), [".", "./es/", "./es/*"]);
+    assert(result.entrypoints["./es/"].isWildcard);
+    assert(Object.values(result.entrypoints["./es/"].resolutions).every((r) => r.isWildcard && !r.resolution));
+    assert.deepStrictEqual(
+      result.problems.filter((p) => "entrypoint" in p && p.entrypoint === "./es/"),
+      [],
+    );
+  });
 });