diff --git a/src/bin/tools/crawl.ts b/src/bin/tools/crawl.ts
index dd53a6d9..b72ae6c9 100644
--- a/src/bin/tools/crawl.ts
+++ b/src/bin/tools/crawl.ts
@@ -1,8 +1,15 @@
 import * as fs from "fs";
 import * as path from "path";
 
-const crawlRec = (dir_path: string, paths: string[]) => {
-    for (const file_name of fs.readdirSync(dir_path)) {
+export const crawlRec = (dir_path: string, paths: string[]) => {
+    let file_names: string[] = [];
+    try {
+        file_names = fs.readdirSync(dir_path);
+    } catch (e) {
+        // dir_path does not exist
+        return;
+    }
+    for (const file_name of file_names) {
         const file_path = path.join(dir_path, file_name);
 
         if (fs.lstatSync(file_path).isDirectory()) {
diff --git a/test/bin/tools/crawl.spec.ts b/test/bin/tools/crawl.spec.ts
new file mode 100644
index 00000000..bf45c538
--- /dev/null
+++ b/test/bin/tools/crawl.spec.ts
@@ -0,0 +1,65 @@
+import path from "path";
+import { it, describe, expect, vi, beforeAll, afterAll } from "vitest";
+import { crawlRec } from "keycloakify/bin/tools/crawl";
+
+describe("crawl", () => {
+    describe("crawRec", () => {
+        beforeAll(() => {
+            vi.mock("node:fs", async () => {
+                const mod = await vi.importActual<typeof import("fs")>("fs");
+                return {
+                    ...mod,
+                    readdirSync: vi.fn().mockImplementation((dir_path: string) => {
+                        switch (dir_path) {
+                            case "root_dir":
+                                return ["sub_1_dir", "file_1", "sub_2_dir", "file_2"];
+                            case path.join("root_dir", "sub_1_dir"):
+                                return ["file_3", "sub_3_dir", "file_4"];
+                            case path.join("root_dir", "sub_1_dir", "sub_3_dir"):
+                                return ["file_5"];
+                            case path.join("root_dir", "sub_2_dir"):
+                                return [];
+                            default: {
+                                const enoent = new Error(`ENOENT: no such file or directory, scandir '${dir_path}'`);
+                                // @ts-ignore
+                                enoent.code = "ENOENT";
+                                // @ts-ignore
+                                enoent.syscall = "open";
+                                // @ts-ignore
+                                enoent.path = dir_path;
+                                throw enoent;
+                            }
+                        }
+                    }),
+                    lstatSync: vi.fn().mockImplementation((file_path: string) => {
+                        return { isDirectory: () => file_path.endsWith("_dir") };
+                    })
+                };
+            });
+        });
+        afterAll(() => {
+            vi.resetAllMocks();
+        });
+        it("returns files under a given dir_path", async () => {
+            const paths: string[] = [];
+            crawlRec("root_dir/sub_1_dir/sub_3_dir", paths);
+            expect(paths).toEqual(["root_dir/sub_1_dir/sub_3_dir/file_5"]);
+        });
+        it("returns files recursively under a given dir_path", async () => {
+            const paths: string[] = [];
+            crawlRec("root_dir", paths);
+            expect(paths).toEqual([
+                "root_dir/sub_1_dir/file_3",
+                "root_dir/sub_1_dir/sub_3_dir/file_5",
+                "root_dir/sub_1_dir/file_4",
+                "root_dir/file_1",
+                "root_dir/file_2"
+            ]);
+        });
+        it("return empty file list if dir_path does not exist", async () => {
+            const paths: string[] = [];
+            crawlRec("404", paths);
+            expect(paths).toEqual([]);
+        });
+    });
+});