diff --git a/.gitignore b/.gitignore
index 05e96ed..5b4bfdc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -9,6 +9,7 @@ dist/
 .DS_Store
 .env*
 !.env.example
+coverage/
 
 # Temporary files
 cache*.json
diff --git a/meta/testing/jest.config.cjs b/meta/testing/jest.config.cjs
index 7a82052..04aacc7 100644
--- a/meta/testing/jest.config.cjs
+++ b/meta/testing/jest.config.cjs
@@ -11,6 +11,9 @@ module.exports = {
     transform: {
         "^.+\\.ts?$": ["ts-jest", {
             useESM: true,
+        }],
+        "^.+\\.js?$": ["ts-jest", {
+            useESM: true,
         }]
     },
     verbose: false,
diff --git a/src/helpers/medias/__tests__/files/image-gif.gif b/src/helpers/medias/__tests__/files/image-gif.gif
new file mode 100644
index 0000000..6c68e32
Binary files /dev/null and b/src/helpers/medias/__tests__/files/image-gif.gif differ
diff --git a/src/helpers/medias/__tests__/files/image-jpeg.jpeg b/src/helpers/medias/__tests__/files/image-jpeg.jpeg
new file mode 100644
index 0000000..c455962
Binary files /dev/null and b/src/helpers/medias/__tests__/files/image-jpeg.jpeg differ
diff --git a/src/helpers/medias/__tests__/files/image-jpg.jpg b/src/helpers/medias/__tests__/files/image-jpg.jpg
new file mode 100644
index 0000000..929985c
Binary files /dev/null and b/src/helpers/medias/__tests__/files/image-jpg.jpg differ
diff --git a/src/helpers/medias/__tests__/files/image-png.png b/src/helpers/medias/__tests__/files/image-png.png
new file mode 100644
index 0000000..7eac084
Binary files /dev/null and b/src/helpers/medias/__tests__/files/image-png.png differ
diff --git a/src/helpers/medias/__tests__/files/image-webp.webp b/src/helpers/medias/__tests__/files/image-webp.webp
new file mode 100644
index 0000000..62cb780
Binary files /dev/null and b/src/helpers/medias/__tests__/files/image-webp.webp differ
diff --git a/src/helpers/medias/__tests__/files/video-mp4.mp4 b/src/helpers/medias/__tests__/files/video-mp4.mp4
new file mode 100644
index 0000000..e21f2a1
Binary files /dev/null and b/src/helpers/medias/__tests__/files/video-mp4.mp4 differ
diff --git a/src/helpers/medias/__tests__/helpers/make-blob-from-file.ts b/src/helpers/medias/__tests__/helpers/make-blob-from-file.ts
new file mode 100644
index 0000000..aaf0a4f
--- /dev/null
+++ b/src/helpers/medias/__tests__/helpers/make-blob-from-file.ts
@@ -0,0 +1,24 @@
+import { readFileSync } from "fs";
+import { resolve } from "path";
+
+export const makeBlobFromFile = async (
+  fileName: string,
+  mimeType: string,
+): Promise<Blob> => {
+  const file = readFileSync(resolve(__dirname, `../files/${fileName}`));
+  return new Blob([file], { type: mimeType });
+};
+
+const makeUint8ArrayFromBlob = async (blob: Blob): Promise<Uint8Array> => {
+  const arrayBuffer = await blob.arrayBuffer();
+  const buffer = Buffer.from(arrayBuffer);
+  return new Uint8Array(buffer);
+};
+
+export const makeUint8ArrayFromFile = async (
+  fileName: string,
+  mimeType: string,
+): Promise<Uint8Array> => {
+  const blob = await makeBlobFromFile(fileName, mimeType);
+  return await makeUint8ArrayFromBlob(blob);
+};
diff --git a/src/helpers/medias/__tests__/parse-blob-for-bluesky.spec.ts b/src/helpers/medias/__tests__/parse-blob-for-bluesky.spec.ts
new file mode 100644
index 0000000..5276d96
--- /dev/null
+++ b/src/helpers/medias/__tests__/parse-blob-for-bluesky.spec.ts
@@ -0,0 +1,51 @@
+import { parseBlobForBluesky } from "../parse-blob-for-bluesky.js";
+import {
+  makeBlobFromFile,
+  makeUint8ArrayFromFile,
+} from "./helpers/make-blob-from-file.js";
+
+let imageBlob: Blob;
+let bskyBlobData: Uint8Array;
+const initBlobsForMime = async (mimeType: string) => {
+  const [type, extension] = mimeType.split("/");
+  const fileName = `${type}-${extension}.${extension}`;
+
+  bskyBlobData = await makeUint8ArrayFromFile(fileName, mimeType);
+  imageBlob = await makeBlobFromFile(fileName, mimeType);
+};
+
+describe("parseBlobForBluesky", () => {
+  describe("when the mime type is not supported", () => {
+    it.each`
+      mimeType
+      ${"video/mp4"}
+      ${"image/webp"}
+    `("should reject for $mimeType", async ({ mimeType }) => {
+      await initBlobsForMime(mimeType);
+
+      await expect(parseBlobForBluesky(imageBlob)).rejects.toContain(
+        "not supported",
+      );
+    });
+  });
+
+  describe("when the mime type is supported", () => {
+    it.each`
+      mimeType
+      ${"image/jpeg"}
+      ${"image/jpg"}
+      ${"image/png"}
+    `(
+      "should resolve bluesky compatible blob for $mimeType",
+      async ({ mimeType }) => {
+        await initBlobsForMime(mimeType);
+
+        const result = await parseBlobForBluesky(imageBlob);
+        expect(result).toStrictEqual({
+          blobData: bskyBlobData,
+          mimeType,
+        });
+      },
+    );
+  });
+});
diff --git a/src/helpers/medias/parse-blob-for-bluesky.ts b/src/helpers/medias/parse-blob-for-bluesky.ts
index 6d73130..826ca90 100644
--- a/src/helpers/medias/parse-blob-for-bluesky.ts
+++ b/src/helpers/medias/parse-blob-for-bluesky.ts
@@ -9,7 +9,7 @@ interface BlueskyBlob {
  */
 export const parseBlobForBluesky = async (blob: Blob): Promise<BlueskyBlob> => {
   return new Promise<BlueskyBlob>((resolve, reject) => {
-    const allowedMimeTypes = ["image/jpeg", "image/png"];
+    const allowedMimeTypes = ["image/jpeg", "image/jpg", "image/png"];
     const mimeType = blob.type;
 
     blob.arrayBuffer().then((ab) => {
diff --git a/src/helpers/post/__tests__/get-post-excerpt.spec.ts b/src/helpers/post/__tests__/get-post-excerpt.spec.ts
new file mode 100644
index 0000000..3a11b4f
--- /dev/null
+++ b/src/helpers/post/__tests__/get-post-excerpt.spec.ts
@@ -0,0 +1,10 @@
+import { getPostExcerpt } from "../get-post-excerpt.js";
+
+describe("getPostExcerpt", () => {
+  it("should return the 25 first characters and remove break lines", () => {
+    const result = getPostExcerpt(
+      "This is a test from\n the Potato Inc. tech lead",
+    );
+    expect(result).toBe("« This is a test from the P... »");
+  });
+});
diff --git a/src/helpers/tweet/__tests__/format-tweet-text.spec.ts b/src/helpers/tweet/__tests__/format-tweet-text.spec.ts
index cbe32b3..3c46b34 100644
--- a/src/helpers/tweet/__tests__/format-tweet-text.spec.ts
+++ b/src/helpers/tweet/__tests__/format-tweet-text.spec.ts
@@ -3,12 +3,25 @@ import { Tweet } from "@the-convocation/twitter-scraper";
 import { formatTweetText } from "../format-tweet-text.js";
 
 describe("formatTweetText", () => {
-  it("should keep untouched a tweet without links", () => {
-    const tweet: Tweet = {
-      text: "This is a tweet without links.",
-      urls: [],
-    } as unknown as Tweet;
-    const result = formatTweetText(tweet);
-    expect(result).toStrictEqual("This is a tweet without links.");
+  describe("when the tweet has links", () => {
+    it("should remove the t.co links from the text", () => {
+      const tweet: Tweet = {
+        text: "This is a tweet with a link",
+        urls: ["https://t.co/abc123"],
+      } as unknown as Tweet;
+      const result = formatTweetText(tweet);
+      expect(result).toStrictEqual("This is a tweet with a link");
+    });
+  });
+
+  describe("when the tweet has media links", () => {
+    it("should remove the t.co links from the text", () => {
+      const tweet: Tweet = {
+        text: "This is a tweet with a media https://t.co/media123",
+        urls: [],
+      } as unknown as Tweet;
+      const result = formatTweetText(tweet);
+      expect(result).toStrictEqual("This is a tweet with a media");
+    });
   });
 });
diff --git a/src/helpers/tweet/__tests__/get-eligible-tweet.spec.ts b/src/helpers/tweet/__tests__/get-eligible-tweet.spec.ts
new file mode 100644
index 0000000..4fc91e4
--- /dev/null
+++ b/src/helpers/tweet/__tests__/get-eligible-tweet.spec.ts
@@ -0,0 +1,54 @@
+import { Tweet } from "@the-convocation/twitter-scraper";
+
+import { getEligibleTweet } from "../get-eligible-tweet.js";
+import { keepRecentTweets, keepSelfQuotes, keepSelfReplies } from "../index.js";
+
+jest.mock("../../../constants.js", () => {
+  return {
+    TWITTER_HANDLE: "username",
+  };
+});
+jest.mock("../index.js", () => {
+  return {
+    keepSelfReplies: jest.fn(),
+    keepSelfQuotes: jest.fn(),
+    keepRecentTweets: jest.fn(),
+  };
+});
+
+describe("getEligibleTweet", () => {
+  it.each`
+    isNotRetweet | isSelfReply | isSelfQuote | isRecentTweet | keep
+    ${false}     | ${false}    | ${false}    | ${false}      | ${false}
+    ${true}      | ${true}     | ${false}    | ${false}      | ${false}
+    ${true}      | ${false}    | ${true}     | ${false}      | ${false}
+    ${true}      | ${false}    | ${false}    | ${true}       | ${false}
+    ${true}      | ${true}     | ${true}     | ${true}       | ${true}
+  `(
+    "should only return keep tweet when all conditions are met",
+    async ({ isNotRetweet, isSelfReply, isSelfQuote, isRecentTweet, keep }) => {
+      // Set mocks values
+      (keepSelfReplies as jest.Mock).mockReturnValue(isSelfReply);
+      (keepSelfQuotes as jest.Mock).mockReturnValue(isSelfQuote);
+      (keepRecentTweets as jest.Mock).mockReturnValue(isRecentTweet);
+
+      // Run test
+      const result = await getEligibleTweet({
+        isRetweet: !isNotRetweet,
+      } as unknown as Tweet);
+
+      // We're only checking for the keep status
+      expect(result).toStrictEqual(
+        keep
+          ? {
+              inReplyToStatus: undefined,
+              inReplyToStatusId: undefined,
+              isRetweet: !isNotRetweet,
+              quotedStatus: undefined,
+              quotedStatusId: undefined,
+            }
+          : undefined,
+      );
+    },
+  );
+});
diff --git a/src/helpers/tweet/__tests__/get-tweet-id-from-permalink.spec.ts b/src/helpers/tweet/__tests__/get-tweet-id-from-permalink.spec.ts
new file mode 100644
index 0000000..46df325
--- /dev/null
+++ b/src/helpers/tweet/__tests__/get-tweet-id-from-permalink.spec.ts
@@ -0,0 +1,10 @@
+import { getTweetIdFromPermalink } from "../get-tweet-id-from-permalink.js";
+
+describe("getTweetIdFromPermalink", () => {
+  it("should return the tweet id", () => {
+    const result = getTweetIdFromPermalink(
+      "https://twitter.com/username/status/1234567890123456789",
+    );
+    expect(result).toBe("1234567890123456789");
+  });
+});
diff --git a/src/helpers/tweet/__tests__/is-tweet-cached.spec.ts b/src/helpers/tweet/__tests__/is-tweet-cached.spec.ts
new file mode 100644
index 0000000..34021a9
--- /dev/null
+++ b/src/helpers/tweet/__tests__/is-tweet-cached.spec.ts
@@ -0,0 +1,21 @@
+import { Tweet } from "@the-convocation/twitter-scraper";
+
+import { isTweetCached } from "../is-tweet-cached.js";
+
+describe("isTweetCached", () => {
+  it("should return true if the tweet is cached", () => {
+    const result = isTweetCached(
+      { id: "1234567890123456789" } as unknown as Tweet,
+      {
+        "1234567890123456789": {
+          mastodon: "mastodonId",
+          bluesky: {
+            cid: "cid",
+            rkey: "rkey",
+          },
+        },
+      },
+    );
+    expect(result).toBe(true);
+  });
+});
diff --git a/src/helpers/tweet/__tests__/keep-recent-tweets.spec.ts b/src/helpers/tweet/__tests__/keep-recent-tweets.spec.ts
new file mode 100644
index 0000000..3c2cf1c
--- /dev/null
+++ b/src/helpers/tweet/__tests__/keep-recent-tweets.spec.ts
@@ -0,0 +1,23 @@
+import { Tweet } from "@the-convocation/twitter-scraper";
+
+import { keepRecentTweets } from "../keep-recent-tweets.js";
+
+describe("keepRecentTweets", () => {
+  describe("when the tweet is recent", () => {
+    it("should return true", () => {
+      const result = keepRecentTweets({
+        timestamp: Date.now(),
+      } as unknown as Tweet);
+      expect(result).toBe(true);
+    });
+  });
+
+  describe("when the tweet is old", () => {
+    it("should return false", () => {
+      const result = keepRecentTweets({
+        timestamp: new Date("1997-01-01").getTime(),
+      } as unknown as Tweet);
+      expect(result).toBe(false);
+    });
+  });
+});
diff --git a/src/helpers/tweet/__tests__/keep-self-quotes.spec.ts b/src/helpers/tweet/__tests__/keep-self-quotes.spec.ts
new file mode 100644
index 0000000..ae03cde
--- /dev/null
+++ b/src/helpers/tweet/__tests__/keep-self-quotes.spec.ts
@@ -0,0 +1,37 @@
+import { Tweet } from "@the-convocation/twitter-scraper";
+
+import { keepSelfQuotes } from "../keep-self-quotes.js";
+
+jest.mock("../../../constants.js", () => {
+  return {
+    TWITTER_HANDLE: "username",
+  };
+});
+
+describe("keepSelfQuotes", () => {
+  describe("when the tweet is a quote", () => {
+    it("should return true when is from the same user", async () => {
+      const result = await keepSelfQuotes({
+        quotedStatus: { username: "username" },
+      } as unknown as Tweet);
+
+      expect(result).toBe(true);
+    });
+
+    it("should return false when is from a different user", async () => {
+      const result = await keepSelfQuotes({
+        quotedStatus: { username: "potatoinc" },
+      } as unknown as Tweet);
+
+      expect(result).toBe(false);
+    });
+  });
+
+  describe("when the tweet is not a quote", () => {
+    it("should return true when is from the same user", async () => {
+      const result = await keepSelfQuotes({} as unknown as Tweet);
+
+      expect(result).toBe(true);
+    });
+  });
+});
diff --git a/src/helpers/tweet/__tests__/keep-self-replies.spec.ts b/src/helpers/tweet/__tests__/keep-self-replies.spec.ts
new file mode 100644
index 0000000..148cfbe
--- /dev/null
+++ b/src/helpers/tweet/__tests__/keep-self-replies.spec.ts
@@ -0,0 +1,37 @@
+import { Tweet } from "@the-convocation/twitter-scraper";
+
+import { keepSelfReplies } from "../keep-self-replies.js";
+
+jest.mock("../../../constants.js", () => {
+  return {
+    TWITTER_HANDLE: "username",
+  };
+});
+
+describe("keepSelfReplies", () => {
+  describe("when the tweet is a reply", () => {
+    it("should return true when is to the same user", async () => {
+      const result = await keepSelfReplies({
+        inReplyToStatus: { username: "username" },
+      } as unknown as Tweet);
+
+      expect(result).toBe(true);
+    });
+
+    it("should return false when is to a different user", async () => {
+      const result = await keepSelfReplies({
+        inReplyToStatus: { username: "potatoinc" },
+      } as unknown as Tweet);
+
+      expect(result).toBe(false);
+    });
+  });
+
+  describe("when the tweet is not a reply", () => {
+    it("should return true when is from the same user", async () => {
+      const result = await keepSelfReplies({} as unknown as Tweet);
+
+      expect(result).toBe(true);
+    });
+  });
+});
diff --git a/src/helpers/tweet/format-tweet-text.ts b/src/helpers/tweet/format-tweet-text.ts
index d8e9407..994b657 100644
--- a/src/helpers/tweet/format-tweet-text.ts
+++ b/src/helpers/tweet/format-tweet-text.ts
@@ -1,7 +1,7 @@
 import { Tweet } from "@the-convocation/twitter-scraper";
 
 export const formatTweetText = (tweet: Tweet): string => {
-  let text = tweet.text || "";
+  let text = tweet.text ?? "";
 
   // Replace urls
   tweet.urls.forEach((url) => {
@@ -12,5 +12,5 @@ export const formatTweetText = (tweet: Tweet): string => {
   text = text.replaceAll(/https:\/\/t\.co\/\w+/g, "");
 
   // Return formatted
-  return text;
+  return text.trim();
 };
diff --git a/src/helpers/tweet/get-eligible-tweet.ts b/src/helpers/tweet/get-eligible-tweet.ts
index 01aea45..43bc0f7 100644
--- a/src/helpers/tweet/get-eligible-tweet.ts
+++ b/src/helpers/tweet/get-eligible-tweet.ts
@@ -28,7 +28,7 @@ export const getEligibleTweet = async (
   if (DEBUG && keep) {
     console.log(
       `✅ : ${tweet.id}: from:@${tweet.username}: ${getPostExcerpt(
-        tweet.text || "",
+        tweet.text ?? "",
       )}`,
     );
   }
diff --git a/src/helpers/url/__tests__/get-redirections.spec.ts b/src/helpers/url/__tests__/get-redirections.spec.ts
new file mode 100644
index 0000000..c0ec9e0
--- /dev/null
+++ b/src/helpers/url/__tests__/get-redirections.spec.ts
@@ -0,0 +1,16 @@
+import { getRedirectedUrl } from "../get-redirection.js";
+
+describe("getRedirectedUrl", () => {
+  describe("when the url is redirected", () => {
+    it("should return the final url", async () => {
+      const result = await getRedirectedUrl("https://t.co/bbJgfyzcJR");
+      expect(result).toStrictEqual("https://github.com/");
+    });
+  });
+  describe("when the url is not redirected", () => {
+    it("should return null", async () => {
+      const result = await getRedirectedUrl("https://t.co/_____null_____");
+      expect(result).toStrictEqual(null);
+    });
+  });
+});
diff --git a/src/helpers/url/__tests__/shortened-urls-replacer.spec.ts b/src/helpers/url/__tests__/shortened-urls-replacer.spec.ts
new file mode 100644
index 0000000..fff7d9a
--- /dev/null
+++ b/src/helpers/url/__tests__/shortened-urls-replacer.spec.ts
@@ -0,0 +1,40 @@
+import { shortenedUrlsReplacer } from "../shortened-urls-replacer.js";
+
+jest.mock("../get-redirection.js", () => {
+  return {
+    getRedirectedUrl: jest.fn((url: string) => {
+      const number = url.match(/\/(\d+)/)?.[1];
+      return Promise.resolve(number ? `https://example.com/${number}` : null);
+    }),
+  };
+});
+
+describe("shortenedUrlsReplacer", () => {
+  it("should replace all urls from a given text with urls", async () => {
+    const result = await shortenedUrlsReplacer(
+      "Some text then url1 https://t.co/1 and url2 https://t.co/2.",
+    );
+
+    expect(result).toStrictEqual(
+      "Some text then url1 https://example.com/1 and url2 https://example.com/2.",
+    );
+  });
+
+  it("should not change the text if there is no url", async () => {
+    const result = await shortenedUrlsReplacer("Some text then the end.");
+
+    expect(result).toStrictEqual("Some text then the end.");
+  });
+
+  describe("when some urls are not resolved properly", () => {
+    it("should only replace the resolved ones", async () => {
+      const result = await shortenedUrlsReplacer(
+        "Some text then url1 https://t.co/1 and url2 https://t.co/broken.",
+      );
+
+      expect(result).toStrictEqual(
+        "Some text then url1 https://example.com/1 and url2 https://t.co/broken.",
+      );
+    });
+  });
+});
diff --git a/src/helpers/url/shortened-urls-replacer.ts b/src/helpers/url/shortened-urls-replacer.ts
index 4e1d670..acea962 100644
--- a/src/helpers/url/shortened-urls-replacer.ts
+++ b/src/helpers/url/shortened-urls-replacer.ts
@@ -11,14 +11,16 @@ export const shortenedUrlsReplacer = async (text: string): Promise<string> => {
   if (!matches.length) {
     return text;
   }
-
   // Get all original urls
   const replacedItems = await Promise.all(
-    matches.map(async (match) => (await getRedirectedUrl(match[0])) ?? ""),
+    matches.map(async (match) => await getRedirectedUrl(match[0])),
   );
 
-  // Replace shortened urls to original ones
+  // Replace shortened urls to original ones, remove non-resolved ones.
   return matches.reduce((description, match, index) => {
-    return description.replace(TWITTER_URL_SHORTENER, replacedItems[index]);
+    const resolvedUrl = replacedItems[index];
+    return resolvedUrl
+      ? description.replace(match[0], resolvedUrl)
+      : description;
   }, text);
 };