diff --git a/package.json b/package.json
index 247da51..bd617cf 100644
--- a/package.json
+++ b/package.json
@@ -32,6 +32,7 @@
     "@types/jest": "^29.5.5",
     "@vercel/ncc": "^0.38.0",
     "jest": "^29.7.0",
+    "jest-mock-extended": "^3.0.5",
     "ts-jest": "^29.1.1",
     "typescript": "^5.2.2"
   }
diff --git a/src/test/comments.test.ts b/src/test/comments.test.ts
new file mode 100644
index 0000000..6919018
--- /dev/null
+++ b/src/test/comments.test.ts
@@ -0,0 +1,55 @@
+/* eslint-disable @typescript-eslint/unbound-method */
+import { DeepMockProxy, mock, mockDeep, MockProxy } from "jest-mock-extended";
+
+import { CommentsApi } from "../github/comments";
+import { ActionLogger, GitHubClient } from "../github/types";
+
+describe("Comments", () => {
+  let comments: CommentsApi;
+  let api: DeepMockProxy<GitHubClient>;
+  let logger: MockProxy<ActionLogger>;
+  const repo = { repo: "example", owner: "me", number: 123 };
+  beforeEach(() => {
+    api = mockDeep<GitHubClient>();
+    logger = mock<ActionLogger>();
+    comments = new CommentsApi(api, logger, repo);
+  });
+
+  describe("Comment action", () => {
+    test("Should comment", async () => {
+      await comments.comment("Hello");
+      expect(api.rest.issues.createComment).toHaveBeenCalledWith({
+        body: "Hello",
+        ...repo,
+        issue_number: repo.number,
+      });
+    });
+
+    test("Should log when commenting", async () => {
+      await comments.comment("Log this");
+      expect(logger.info).toHaveBeenCalledWith("Commenting: Log this");
+    });
+
+    test("Should not comment on silent mode", async () => {
+      comments = new CommentsApi(api, logger, repo, true);
+      await comments.comment("Example");
+      expect(api.rest.issues.createComment).not.toHaveBeenCalled();
+    });
+
+    test("Should log while in silent mode", async () => {
+      comments = new CommentsApi(api, logger, repo, true);
+      await comments.comment("Bye");
+      expect(logger.info).toHaveBeenCalledWith("Commenting: Bye");
+    });
+
+    test("Should override silent mode", async () => {
+      comments = new CommentsApi(api, logger, repo, true);
+      await comments.comment("Overrider", true);
+      expect(api.rest.issues.createComment).toHaveBeenCalledWith({
+        body: "Overrider",
+        ...repo,
+        issue_number: repo.number,
+      });
+    });
+  });
+});
diff --git a/src/test/index.ts b/src/test/index.ts
deleted file mode 100644
index 3a327af..0000000
--- a/src/test/index.ts
+++ /dev/null
@@ -1,3 +0,0 @@
-test("adds 1 + 2 to equal 3", () => {
-  expect(1 + 2).toBe(3);
-});
diff --git a/yarn.lock b/yarn.lock
index 7932878..0020cfc 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -2697,6 +2697,13 @@ jest-message-util@^29.7.0:
     slash "^3.0.0"
     stack-utils "^2.0.3"
 
+jest-mock-extended@^3.0.5:
+  version "3.0.5"
+  resolved "https://registry.yarnpkg.com/jest-mock-extended/-/jest-mock-extended-3.0.5.tgz#ebf208e363f4f1db603b81fb005c4055b7c1c8b7"
+  integrity sha512-/eHdaNPUAXe7f65gHH5urc8SbRVWjYxBqmCgax2uqOBJy8UUcCBMN1upj1eZ8y/i+IqpyEm4Kq0VKss/GCCTdw==
+  dependencies:
+    ts-essentials "^7.0.3"
+
 jest-mock@^29.7.0:
   version "29.7.0"
   resolved "https://registry.yarnpkg.com/jest-mock/-/jest-mock-29.7.0.tgz#4e836cf60e99c6fcfabe9f99d017f3fdd50a6347"
@@ -3781,6 +3788,11 @@ tr46@~0.0.3:
   resolved "https://registry.yarnpkg.com/tr46/-/tr46-0.0.3.tgz#8184fd347dac9cdc185992f3a6622e14b9d9ab6a"
   integrity sha512-N3WMsuqV66lT30CrXNbEjx4GEwlow3v6rr4mCcv6prnfwhS01rkgyFdjPNBYd9br7LpXV1+Emh01fHnq2Gdgrw==
 
+ts-essentials@^7.0.3:
+  version "7.0.3"
+  resolved "https://registry.yarnpkg.com/ts-essentials/-/ts-essentials-7.0.3.tgz#686fd155a02133eedcc5362dc8b5056cde3e5a38"
+  integrity sha512-8+gr5+lqO3G84KdiTSMRLtuyJ+nTBVRKuCrK4lidMPdVeEp0uqC875uE5NMcaA7YYMN7XsNiFQuMvasF8HT/xQ==
+
 ts-jest@^29.1.1:
   version "29.1.1"
   resolved "https://registry.yarnpkg.com/ts-jest/-/ts-jest-29.1.1.tgz#f58fe62c63caf7bfcc5cc6472082f79180f0815b"