diff --git a/__tests__/index.test.js b/__tests__/index.test.js
index 0fe2967..87686be 100644
--- a/__tests__/index.test.js
+++ b/__tests__/index.test.js
@@ -1,4 +1,8 @@
-const { validateAuthentication, replacePlaceholders } = require("../index");
+const {
+  validateAuthentication,
+  replacePlaceholders,
+  readReplaceAndWriteFiles,
+} = require("../index");
 const fs = require("fs");
 const path = require("path");
 const os = require("os");
@@ -67,6 +71,41 @@ describe("replacePlaceholders", () => {
   });
 });
 
+describe("readReplaceAndWriteFiles", () => {
+  let tempDir;
+
+  beforeEach(async () => {
+    tempDir = await fs.promises.mkdtemp(
+      path.join(os.tmpdir(), "replace-test-"),
+    );
+    process.env.GITHUB_SHA = "test-sha";
+    process.env.GITHUB_REF = "test-ref";
+  });
+
+  afterEach(async () => {
+    if (tempDir) {
+      await fs.promises.rm(tempDir, { recursive: true, force: true });
+    }
+  });
+
+  it("should find files and replace placeholders", async () => {
+    const fileName = "test.js";
+    const filePath = path.join(tempDir, fileName);
+    const content = "hash: {{gitHash}}, ref: {{gitRef}}, host: {{hostname}}";
+    await fs.promises.writeFile(filePath, content);
+
+    const pattern = "*.js";
+    // We pass tempDir as the prefix so glob searches inside it
+    await readReplaceAndWriteFiles(pattern, tempDir, "test-host");
+
+    const updatedContent = await fs.promises.readFile(filePath, "utf8");
+
+    expect(updatedContent).toContain("hash: test-sha");
+    expect(updatedContent).toContain("ref: test-ref");
+    expect(updatedContent).toContain("host: test-host");
+  });
+});
+
 describe("glob functionality", () => {
   let tempDir;