From 3cc37aabac32ae777eae2c5643620b96c26de012 Mon Sep 17 00:00:00 2001
From: alexander-akait <4567934+alexander-akait@users.noreply.github.com>
Date: Fri, 16 Oct 2026 11:30:30 +0000
Subject: [PATCH] fix: treat a file where a watched directory should be like a
 missing directory

---
 .changeset/missing-under-file.md |  5 ++++
 lib/DirectoryWatcher.js          |  3 ++
 test/MissingUnderFile.test.js    | 50 ++++++++++++++++++++++++++++++++
 3 files changed, 58 insertions(+)
 create mode 100644 .changeset/missing-under-file.md
 create mode 100644 test/MissingUnderFile.test.js

diff --git a/.changeset/missing-under-file.md b/.changeset/missing-under-file.md
new file mode 100644
index 0000000..b0bb0c4
--- /dev/null
+++ b/.changeset/missing-under-file.md
@@ -0,0 +1,5 @@
+---
+"watchpack": patch
+---
+
+Watch a missing file whose parent path is a file (e.g. `src/foo/index.js`, tried by a resolver alias, while `src/foo` is a file) like one whose parent is missing: no more `ENOTDIR` "Watchpack Error (initial scan)" log, and the file is reported once the parent becomes a directory (fixes #226's case).
diff --git a/lib/DirectoryWatcher.js b/lib/DirectoryWatcher.js
index 18452ce..c8fb44d 100644
--- a/lib/DirectoryWatcher.js
+++ b/lib/DirectoryWatcher.js
@@ -904,6 +904,9 @@ class DirectoryWatcher extends EventEmitter {
 					// (see #187).
 					if (
 						err.code === "ENOENT" ||
+						// a file where the directory should be, e.g. `src/foo` for a
+						// missing `src/foo/index.js` that a resolver tried (#226)
+						err.code === "ENOTDIR" ||
 						err.code === "EPERM" ||
 						err.code === "EACCES" ||
 						err.code === "ENODEV" ||
diff --git a/test/MissingUnderFile.test.js b/test/MissingUnderFile.test.js
new file mode 100644
index 0000000..4b0d061
--- /dev/null
+++ b/test/MissingUnderFile.test.js
@@ -0,0 +1,50 @@
+"use strict";
+
+const path = require("path");
+const Watchpack = require("../lib");
+const TestHelper = require("./helpers/TestHelper");
+
+const fixtures = path.join(__dirname, "fixtures");
+const testHelper = new TestHelper(fixtures);
+
+// eslint-disable-next-line jest/no-confusing-set-timeout
+jest.setTimeout(20000);
+
+describe("Missing file below a path that is a file (#226)", () => {
+	beforeEach((done) => {
+		testHelper.before(done);
+	});
+
+	/** @type {InstanceType<typeof Watchpack>[]} */
+	let watchers = [];
+
+	afterEach((done) => {
+		// closed here, not in the test, so a failure cannot leave one running
+		for (const w of watchers) w.close();
+		watchers = [];
+		jest.restoreAllMocks();
+		testHelper.after(done);
+	});
+
+	it("should report the file once its parent turns from a file into a directory", (done) => {
+		// a resolver tried `foo/index.js` while `foo` is a file
+		testHelper.file("foo");
+		const missing = path.join(fixtures, "foo", "index.js");
+		const errors = jest.spyOn(console, "error").mockImplementation(() => {});
+		testHelper.tick(1000, () => {
+			const w = new Watchpack({ aggregateTimeout: 100 });
+			watchers.push(w);
+			w.on("change", (item) => {
+				expect(item).toBe(missing);
+				expect(errors).not.toHaveBeenCalled();
+				done();
+			});
+			w.watch({ missing: [missing], startTime: Date.now() });
+			testHelper.tick(1000, () => {
+				testHelper.remove("foo");
+				testHelper.dir("foo");
+				testHelper.file(path.join("foo", "index.js"));
+			});
+		});
+	});
+});