diff --git a/Cargo.lock b/Cargo.lock
index 27fd152..2c495cc 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -23,6 +23,131 @@ version = "1.0.102"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7f202df86484c868dbad7eaa557ef785d5c66295e41b460ef922eca0723b842c"
 
+[[package]]
+name = "async-channel"
+version = "1.9.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "81953c529336010edd6d8e358f886d9581267795c61b19475b71314bffa46d35"
+dependencies = [
+ "concurrent-queue",
+ "event-listener 2.5.3",
+ "futures-core",
+]
+
+[[package]]
+name = "async-channel"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "924ed96dd52d1b75e9c1a3e6275715fd320f5f9439fb5a4a11fa51f4221158d2"
+dependencies = [
+ "concurrent-queue",
+ "event-listener-strategy",
+ "futures-core",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "async-executor"
+version = "1.14.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c96bf972d85afc50bf5ab8fe2d54d1586b4e0b46c97c50a0c9e71e2f7bcd812a"
+dependencies = [
+ "async-task",
+ "concurrent-queue",
+ "fastrand",
+ "futures-lite",
+ "pin-project-lite",
+ "slab",
+]
+
+[[package]]
+name = "async-global-executor"
+version = "2.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "05b1b633a2115cd122d73b955eadd9916c18c8f510ec9cd1686404c60ad1c29c"
+dependencies = [
+ "async-channel 2.5.0",
+ "async-executor",
+ "async-io",
+ "async-lock",
+ "blocking",
+ "futures-lite",
+ "once_cell",
+]
+
+[[package]]
+name = "async-io"
+version = "2.6.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "456b8a8feb6f42d237746d4b3e9a178494627745c3c56c6ea55d92ba50d026fc"
+dependencies = [
+ "autocfg",
+ "cfg-if",
+ "concurrent-queue",
+ "futures-io",
+ "futures-lite",
+ "parking",
+ "polling",
+ "rustix",
+ "slab",
+ "windows-sys",
+]
+
+[[package]]
+name = "async-lock"
+version = "3.4.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "290f7f2596bd5b78a9fec8088ccd89180d7f9f55b94b0576823bbbdc72ee8311"
+dependencies = [
+ "event-listener 5.4.1",
+ "event-listener-strategy",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "async-std"
+version = "1.13.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "2c8e079a4ab67ae52b7403632e4618815d6db36d2a010cfe41b02c1b1578f93b"
+dependencies = [
+ "async-channel 1.9.0",
+ "async-global-executor",
+ "async-io",
+ "async-lock",
+ "crossbeam-utils",
+ "futures-channel",
+ "futures-core",
+ "futures-io",
+ "futures-lite",
+ "gloo-timers",
+ "kv-log-macro",
+ "log",
+ "memchr",
+ "once_cell",
+ "pin-project-lite",
+ "pin-utils",
+ "slab",
+ "wasm-bindgen-futures",
+]
+
+[[package]]
+name = "async-task"
+version = "4.7.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b75356056920673b02621b35afd0f7dda9306d03c79a30f5c56c44cf256e3de"
+
+[[package]]
+name = "atomic-waker"
+version = "1.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1505bd5d3d116872e7271a6d4e16d81d0c8570876c8de68093a09ac269d8aac0"
+
+[[package]]
+name = "autocfg"
+version = "1.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f2032f911046de80f0a198e0901378627c33f59ea0ac00e363d481118bd70a53"
+
 [[package]]
 name = "base64"
 version = "0.22.1"
@@ -35,6 +160,19 @@ version = "2.12.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "84d7ced0ae9557296835c32bf1b1e02b44c746701f898460fb000d7eaa84f00a"
 
+[[package]]
+name = "blocking"
+version = "1.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e83f8d02be6967315521be875afa792a316e28d57b5a2d401897e2a7921b7f21"
+dependencies = [
+ "async-channel 2.5.0",
+ "async-task",
+ "futures-io",
+ "futures-lite",
+ "piper",
+]
+
 [[package]]
 name = "bumpalo"
 version = "3.20.3"
@@ -76,8 +214,9 @@ dependencies = [
 
 [[package]]
 name = "clean_file"
-version = "0.8.3"
+version = "0.8.4"
 dependencies = [
+ "async-std",
  "futures",
  "serde",
  "serde_json",
@@ -86,6 +225,15 @@ dependencies = [
  "tokio",
 ]
 
+[[package]]
+name = "concurrent-queue"
+version = "2.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4ca0197aee26d1ae37445ee532fefce43251d24cc7c166799f4d46817f1d3973"
+dependencies = [
+ "crossbeam-utils",
+]
+
 [[package]]
 name = "const_format"
 version = "0.2.36"
@@ -125,6 +273,12 @@ dependencies = [
  "cfg-if",
 ]
 
+[[package]]
+name = "crossbeam-utils"
+version = "0.8.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d0a5c400df2834b80a4c3327b3aad3a4c4cd4de0629063962b03235697506a28"
+
 [[package]]
 name = "deranged"
 version = "0.5.8"
@@ -157,6 +311,33 @@ dependencies = [
  "windows-sys",
 ]
 
+[[package]]
+name = "event-listener"
+version = "2.5.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0206175f82b8d6bf6652ff7d71a1e27fd2e4efde587fd368662814d6ec1d9ce0"
+
+[[package]]
+name = "event-listener"
+version = "5.4.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e13b66accf52311f30a0db42147dadea9850cb48cd070028831ae5f5d4b856ab"
+dependencies = [
+ "concurrent-queue",
+ "parking",
+ "pin-project-lite",
+]
+
+[[package]]
+name = "event-listener-strategy"
+version = "0.5.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8be9f3dfaaffdae2972880079a491a1a8bb7cbed0b8dd7a347f668b4150a3b93"
+dependencies = [
+ "event-listener 5.4.1",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "fastrand"
 version = "2.4.1"
@@ -248,6 +429,19 @@ version = "0.3.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "cecba35d7ad927e23624b22ad55235f2239cfa44fd10428eecbeba6d6a717718"
 
+[[package]]
+name = "futures-lite"
+version = "2.6.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f78e10609fe0e0b3f4157ffab1876319b5b0db102a2c60dc4626306dc46b44ad"
+dependencies = [
+ "fastrand",
+ "futures-core",
+ "futures-io",
+ "parking",
+ "pin-project-lite",
+]
+
 [[package]]
 name = "futures-macro"
 version = "0.3.32"
@@ -302,6 +496,18 @@ dependencies = [
  "wasip3",
 ]
 
+[[package]]
+name = "gloo-timers"
+version = "0.3.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "bbb143cf96099802033e0d4f4963b19fd2e0b728bcf076cd9cf7f6634f092994"
+dependencies = [
+ "futures-channel",
+ "futures-core",
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "hashbrown"
 version = "0.15.5"
@@ -323,6 +529,12 @@ version = "0.5.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "2304e00983f87ffb38b55b444b5e3b60a884b5d30c0fca7d82fe33449bbe55ea"
 
+[[package]]
+name = "hermit-abi"
+version = "0.5.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc0fef456e4baa96da950455cd02c081ca953b141298e41db3fc7e36b1da849c"
+
 [[package]]
 name = "id-arena"
 version = "2.3.0"
@@ -391,6 +603,15 @@ version = "0.2.19"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a4933f3f57a8e9d9da04db23fb153356ecaf00cbd14aee46279c33dc80925c37"
 
+[[package]]
+name = "kv-log-macro"
+version = "1.0.7"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "0de8b303297635ad57c9f5059fd9cee7a47f8e8daa09df0fcd07dd39fb22977f"
+dependencies = [
+ "log",
+]
+
 [[package]]
 name = "leb128fmt"
 version = "0.1.0"
@@ -423,6 +644,9 @@ name = "log"
 version = "0.4.32"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "953f07c43838f8e6f9758cab68bf5bed85465e7587ebe0b823f1bcd81978ad3a"
+dependencies = [
+ "value-bag",
+]
 
 [[package]]
 name = "memchr"
@@ -500,6 +724,12 @@ dependencies = [
  "vcpkg",
 ]
 
+[[package]]
+name = "parking"
+version = "2.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f38d5652c16fde515bb1ecef450ab0f6a219d619a7274976324d5e377f7dceba"
+
 [[package]]
 name = "parking_lot"
 version = "0.12.5"
@@ -529,12 +759,43 @@ version = "0.2.17"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "a89322df9ebe1c1578d689c92318e070967d1042b512afbe49518723f4e6d5cd"
 
+[[package]]
+name = "pin-utils"
+version = "0.1.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8b870d8c151b6f2fb93e84a13146138f05d02ed11c7e7c54f8826aaaf7c9f184"
+
+[[package]]
+name = "piper"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c835479a4443ded371d6c535cbfd8d31ad92c5d23ae9770a61bc155e4992a3c1"
+dependencies = [
+ "atomic-waker",
+ "fastrand",
+ "futures-io",
+]
+
 [[package]]
 name = "pkg-config"
 version = "0.3.33"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "19f132c84eca552bf34cab8ec81f1c1dcc229b811638f9d283dceabe58c5569e"
 
+[[package]]
+name = "polling"
+version = "3.11.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "5d0e4f59085d47d8241c88ead0f274e8a0cb551f3625263c05eb8dd897c34218"
+dependencies = [
+ "cfg-if",
+ "concurrent-queue",
+ "hermit-abi",
+ "pin-project-lite",
+ "rustix",
+ "windows-sys",
+]
+
 [[package]]
 name = "powerfmt"
 version = "0.2.0"
@@ -916,6 +1177,12 @@ dependencies = [
  "wasm-bindgen",
 ]
 
+[[package]]
+name = "value-bag"
+version = "1.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ba6f5989077681266825251a52748b8c1d8a4ad098cc37e440103d0ea717fc0"
+
 [[package]]
 name = "vcpkg"
 version = "0.2.15"
@@ -959,6 +1226,16 @@ dependencies = [
  "wasm-bindgen-shared",
 ]
 
+[[package]]
+name = "wasm-bindgen-futures"
+version = "0.4.72"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "9473dbd2991ae90b6291c3c32c30c6187ac49aa32f9905d1cce280ec1e110b0f"
+dependencies = [
+ "js-sys",
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "wasm-bindgen-macro"
 version = "0.2.122"
diff --git a/Cargo.toml b/Cargo.toml
index 6443b21..2394ca2 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,6 @@
 [package]
 name = "clean_file"
-version = "0.8.3"
+version = "0.8.4"
 edition = "2024"
 rust-version = "1.95"
 
@@ -14,3 +14,4 @@ textsender_models = { git = "ssh://git@git.kundeng.us/phoenix/textsender-models.
 
 [dev-dependencies]
 tempfile = { version = "3.27.0" }
+async-std = { version = "1.13.2" }
diff --git a/src/main.rs b/src/main.rs
index 0503ddf..d4fbe0f 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -23,7 +23,7 @@ async fn main() {
     match prsr.file_dump().await {
         Ok(contacts) => {
             prsr.print_phone_numbers(&contacts);
-            prsr.save_file(contacts).await;
+            prsr.save_file(contacts, parser::DEFAULT_OUTPUT_FILE).await;
         }
         Err(err) => {
             eprintln!("Error: {err:?}");
diff --git a/src/parser/mod.rs b/src/parser/mod.rs
index 9239aa8..afb26a2 100644
--- a/src/parser/mod.rs
+++ b/src/parser/mod.rs
@@ -1,5 +1,6 @@
 use std::io::BufRead;
 
+pub const DEFAULT_OUTPUT_FILE: &str = "numbers.json";
 const LETTERS: &str = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ";
 
 #[derive(Clone, Debug, Default)]
@@ -40,11 +41,13 @@ impl NumberParser {
         }
     }
 
-    pub async fn save_file(&self, numbers: Vec<textsender_models::contact::Contact>) {
-        let filename = String::from("numbers.json");
-
+    pub async fn save_file(
+        &self,
+        numbers: Vec<textsender_models::contact::Contact>,
+        filename: &str,
+    ) {
         match serde_json::to_string(&numbers) {
-            Ok(json_string) => match std::fs::write(&filename, json_string) {
+            Ok(json_string) => match std::fs::write(filename, json_string) {
                 Ok(_) => {
                     println!("Saved to: {filename:?}");
                 }
@@ -166,3 +169,99 @@ impl NumberParser {
         parsed
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use textsender_models::contact::Contact;
+
+    const TEST_NUMBERS_0: &str = "tests/numbers-0.txt";
+
+    #[test]
+    fn test_file_dump() {
+        let file_exists = {
+            let path = std::path::Path::new(TEST_NUMBERS_0);
+            path.exists()
+        };
+
+        assert_eq!(true, file_exists, "File does not exists {TEST_NUMBERS_0:?}");
+
+        let filename = String::from(TEST_NUMBERS_0);
+        let prsr = super::NumberParser { filepath: filename };
+        let original: Vec<Contact> = vec![
+            Contact {
+                phone_number: String::from("+13055550112"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+13175550123"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+14155550135"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+16085550190"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+17135550167"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+16025550177"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+13605550158"),
+                ..Default::default()
+            },
+            Contact {
+                phone_number: String::from("+12175550194"),
+                ..Default::default()
+            },
+        ];
+
+        match async_std::task::block_on(prsr.file_dump()) {
+            Ok(contacts) => {
+                assert!((contacts.len() > 0), "No contacts has been parsed");
+
+                let phone_numbers_1: std::collections::HashSet<_> =
+                    contacts.iter().map(|p| p.phone_number.clone()).collect();
+                let phone_numbers_2: std::collections::HashSet<_> =
+                    original.iter().map(|p| p.phone_number.clone()).collect();
+                assert_eq!(phone_numbers_1, phone_numbers_2, "No match");
+            }
+            Err(err) => {
+                assert!(false, "Error: {err:?}");
+            }
+        };
+    }
+
+    #[test]
+    fn test_save_file() {
+        let prsr = super::NumberParser {
+            filepath: String::from(TEST_NUMBERS_0),
+        };
+        let results = async_std::task::block_on(prsr.file_dump());
+        assert!(results.is_ok(), "File dump not successful");
+        let test_output_file: &str = "test-numbers.json";
+
+        let contacts = results.unwrap();
+        async_std::task::block_on(prsr.save_file(contacts, test_output_file));
+        let file_exists = {
+            let path = std::path::Path::new(test_output_file);
+            path.exists()
+        };
+
+        assert!(file_exists, "Contacts were not saved");
+        match std::fs::remove_file(test_output_file) {
+            Ok(_) => {
+                println!("File removed");
+            }
+            Err(err) => {
+                assert!(false, "Error: {err:?}");
+            }
+        }
+    }
+}
diff --git a/tests/numbers.txt b/tests/numbers-0.txt
similarity index 100%
rename from tests/numbers.txt
rename to tests/numbers-0.txt