diff --git a/analscript.js b/analscript.js
index 3da3f4f..94001f5 100644
--- a/analscript.js
+++ b/analscript.js
@@ -1,4 +1,4 @@
-import { anallify, stringify } from './lib/stdlib.js';
+import { anallify, stringify } from './lib/std.js';
 
 export { anallify, stringify };
 export default { anallify, stringify };
diff --git a/cli.js b/cli.js
index 67a9e2a..6f21ee8 100644
--- a/cli.js
+++ b/cli.js
@@ -1,12 +1,13 @@
 #!/usr/bin/env node
 import help from './lib/help.js';
+import { graceful } from './lib/utils.js';
 
 import {
   run,
   compile,
   anallify,
   stringify,
-} from './lib/stdlib.js';
+} from './lib/std.js';
 
 import {
   RUN,
@@ -33,4 +34,4 @@ function cli() {
   process.stdout.write(`${output}\n`);
 }
 
-cli();
+graceful(cli);
diff --git a/lib/stdlib.js b/lib/std.js
similarity index 75%
rename from lib/stdlib.js
rename to lib/std.js
index 1a0e1c4..505049f 100644
--- a/lib/stdlib.js
+++ b/lib/std.js
@@ -1,18 +1,16 @@
 import fs from 'node:fs';
 
-import checker from './utils.js';
+import { checker } from './utils.js';
 import { ERROR, SUCCESS } from './dictionary.js';
 import { ANAL_CHARACTERS } from './constants.js';
 
 export function anallify(string) {
   if (!checker(string)) {
-    process.stderr.write(`${ERROR.notString}\n`);
-    return process.exit(1);
+    throw new Error(ERROR.notString);
   }
 
   if (!string) {
-    process.stderr.write(`${ERROR.missingArgument}\n`);
-    return process.exit(1);
+    throw new Error(ERROR.missingArgument);
   }
 
   let anal = '';
@@ -29,13 +27,11 @@ export function anallify(string) {
 
 export function stringify(anal) {
   if (!checker(anal)) {
-    process.stderr.write(`${ERROR.notString}\n`);
-    return process.exit(1);
+    throw new Error(ERROR.notString);
   }
 
   if (!anal) {
-    process.stderr.write(`${ERROR.missingArgument}\n`);
-    return process.exit(1);
+    throw new Error(ERROR.missingArgument);
   }
 
   let string = '';
@@ -56,23 +52,20 @@ export function run(file) {
     const contents = fs.readFileSync(file, { encoding: 'utf-8' });
     return stringify(contents);
   } catch (error) {
-    process.stderr.write(`${ERROR.fileNotFound}\n`);
-    return process.exit(1);
+    throw new Error(ERROR.fileNotFound);
   }
 }
 
 export function compile(file) {
   try {
     const contents = fs.readFileSync(file, { encoding: 'utf-8' });
-
     let filename = file.split('.');
     filename = filename.filter((element, index) => index < filename.length - 1);
     filename = filename.join('.');
-
     fs.writeFileSync(`${filename}.anal`, anallify(contents), { encoding: 'utf-8' });
     process.stdout.write(`${SUCCESS.compileSuccess}`);
+    return true;
   } catch (error) {
-    process.stderr.write(`${ERROR.fileNotFound}\n`);
-    process.exit(1);
+    throw new Error(ERROR.fileNotFound);
   }
 }
diff --git a/lib/utils.js b/lib/utils.js
index 526170d..ec47d2c 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -1,3 +1,12 @@
-export default function checker(input) {
+export function checker(input) {
   return typeof input === 'string';
 }
+
+export function graceful(fn) {
+  try {
+    fn();
+  } catch (error) {
+    process.stderr.write(`${error.message}\n`);
+    process.exit(1);
+  }
+}
diff --git a/tests/hello.anus b/tests/hello.anus
new file mode 100644
index 0000000..99f615c
--- /dev/null
+++ b/tests/hello.anus
@@ -0,0 +1 @@
+Hello, Analscript!
\ No newline at end of file
diff --git a/tests/seeds.js b/tests/seeds.js
index 2d3d790..182320f 100644
--- a/tests/seeds.js
+++ b/tests/seeds.js
@@ -1,3 +1,6 @@
+export const NUMERIC_INPUT = 1;
+export const EMPTY_STRING_INPUT = '';
+
 export const STRINGIFY_CORRECT_OUTPUT = 'B';
 export const STRINGIFY_WRONG_OUTPUT = '🍑🍆🍑🍆';
 export const STRINGIFY_INPUT = '🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆';
@@ -9,3 +12,7 @@ export const ANALLIFY_CORRECT_OUTPUT = '🍑🍆🍑🍆🍑🍆🍑🍆🍑🍆
 export const ANAL_FILE_LOCATION = 'tests/script.anal';
 export const RUN_CORRECT_OUTPUT = 'Welcome to Analscript!';
 export const RUN_WRONG_OUTPUT = 'Welcome to Jurassic Park!';
+
+export const COMPILE_CORRECT_OUTPUT = true;
+export const FILE_LOCATION = 'tests/hello.anus';
+export const COMPILED_FILE_LOCATION = 'tests/hello.anal';
diff --git a/tests/std.test.js b/tests/std.test.js
new file mode 100644
index 0000000..f45eb79
--- /dev/null
+++ b/tests/std.test.js
@@ -0,0 +1,89 @@
+import fs from 'node:fs';
+import { test, expect, describe } from 'vitest';
+
+import {
+  FILE_LOCATION,
+  NUMERIC_INPUT,
+  ANALLIFY_INPUT,
+  STRINGIFY_INPUT,
+  RUN_WRONG_OUTPUT,
+  ANAL_FILE_LOCATION,
+  EMPTY_STRING_INPUT,
+  RUN_CORRECT_OUTPUT,
+  ANALLIFY_WRONG_OUTPUT,
+  STRINGIFY_WRONG_OUTPUT,
+  COMPILE_CORRECT_OUTPUT,
+  COMPILED_FILE_LOCATION,
+  ANALLIFY_CORRECT_OUTPUT,
+  STRINGIFY_CORRECT_OUTPUT,
+} from './seeds.js';
+
+import {
+  run,
+  anallify,
+  stringify,
+  compile,
+} from '../lib/std.js';
+import { ERROR } from '../lib/dictionary.js';
+
+describe('Anallify', () => {
+  test('Encode string to anal', () => {
+    expect(anallify(ANALLIFY_INPUT)).toBe(ANALLIFY_CORRECT_OUTPUT);
+    expect(anallify(ANALLIFY_INPUT)).not.toBe(ANALLIFY_WRONG_OUTPUT);
+  });
+
+  test('Throw error if argument is not a string', () => {
+    expect(() => anallify(1)).toThrowError(Error(ERROR.notString));
+  });
+
+  test('Throw error if argument is missing', () => {
+    expect(() => anallify(EMPTY_STRING_INPUT)).toThrowError(
+      Error(ERROR.missingArgument),
+    );
+  });
+});
+
+describe('Stringify', () => {
+  test('Decode anal to string', () => {
+    expect(stringify(STRINGIFY_INPUT)).toBe(STRINGIFY_CORRECT_OUTPUT);
+    expect(stringify(STRINGIFY_INPUT)).not.toBe(STRINGIFY_WRONG_OUTPUT);
+  });
+
+  test('Throw error if argument is not a string', () => {
+    expect(() => stringify(NUMERIC_INPUT)).toThrowError(
+      Error(ERROR.notString),
+    );
+  });
+
+  test('Throw error if argument is missing', () => {
+    expect(() => stringify(EMPTY_STRING_INPUT)).toThrowError(
+      Error(ERROR.missingArgument),
+    );
+  });
+});
+
+describe('Run', () => {
+  test('Run .anal file', () => {
+    expect(run(ANAL_FILE_LOCATION)).toBe(RUN_CORRECT_OUTPUT);
+    expect(run(ANAL_FILE_LOCATION)).not.toBe(RUN_WRONG_OUTPUT);
+  });
+
+  test('Throw error if file is not found', () => {
+    expect(() => run(EMPTY_STRING_INPUT)).toThrowError(
+      Error(ERROR.fileNotFound),
+    );
+  });
+});
+
+describe('Compile', () => {
+  test('Compile file to .anal', () => {
+    expect(compile(FILE_LOCATION)).toBe(COMPILE_CORRECT_OUTPUT);
+    fs.rmSync(COMPILED_FILE_LOCATION);
+  });
+
+  test('Throw error if file is not found', () => {
+    expect(() => compile(EMPTY_STRING_INPUT)).toThrowError(
+      Error(ERROR.fileNotFound),
+    );
+  });
+});
diff --git a/tests/stdlib.test.js b/tests/stdlib.test.js
deleted file mode 100644
index b25089b..0000000
--- a/tests/stdlib.test.js
+++ /dev/null
@@ -1,34 +0,0 @@
-import { test, expect } from 'vitest';
-
-import {
-  ANALLIFY_INPUT,
-  STRINGIFY_INPUT,
-  RUN_WRONG_OUTPUT,
-  ANAL_FILE_LOCATION,
-  RUN_CORRECT_OUTPUT,
-  ANALLIFY_WRONG_OUTPUT,
-  STRINGIFY_WRONG_OUTPUT,
-  ANALLIFY_CORRECT_OUTPUT,
-  STRINGIFY_CORRECT_OUTPUT,
-} from './seeds.js';
-
-import {
-  run,
-  anallify,
-  stringify,
-} from '../lib/stdlib.js';
-
-test('Encode string to anal', () => {
-  expect(anallify(ANALLIFY_INPUT)).toBe(ANALLIFY_CORRECT_OUTPUT);
-  expect(anallify(ANALLIFY_INPUT)).not.toBe(ANALLIFY_WRONG_OUTPUT);
-});
-
-test('Decode anal to string', () => {
-  expect(stringify(STRINGIFY_INPUT)).toBe(STRINGIFY_CORRECT_OUTPUT);
-  expect(stringify(STRINGIFY_INPUT)).not.toBe(STRINGIFY_WRONG_OUTPUT);
-});
-
-test('Run .anal file', () => {
-  expect(run(ANAL_FILE_LOCATION)).toBe(RUN_CORRECT_OUTPUT);
-  expect(run(ANAL_FILE_LOCATION)).not.toBe(RUN_WRONG_OUTPUT);
-});
diff --git a/tests/utils.test.js b/tests/utils.test.js
new file mode 100644
index 0000000..0ee5511
--- /dev/null
+++ b/tests/utils.test.js
@@ -0,0 +1,16 @@
+import {
+  vi,
+  test,
+  expect,
+  describe,
+} from 'vitest';
+
+import { graceful } from '../lib/utils';
+
+describe('Graceful', () => {
+  test('Execute graceful', () => {
+    const fn = vi.fn();
+    graceful(fn);
+    expect(fn).toBeCalled();
+  });
+});