diff --git a/src/tests/add/dep.spec.ts b/src/tests/add/dep.spec.ts
index d3b2244..c96a06e 100644
--- a/src/tests/add/dep.spec.ts
+++ b/src/tests/add/dep.spec.ts
@@ -1,145 +1,99 @@
-import { filesystem, system } from 'gluegun';
-const stripANSI = require('strip-ansi');
+import { filesystem } from 'gluegun';
 import * as latestVersion from 'latest-version';
 import Dep from '../../commands/add/dep';
+import {
+  createDefaultNbxConfig,
+  expectFailCli,
+  expectGitCommits,
+  testCli,
+} from '../test-helpers.spec';
 
 jest.setTimeout(90000);
 
-/* eslint-disable no-console,max-nested-callbacks,@typescript-eslint/ban-ts-ignore */
-let consoleLogOutput: string[];
-let execPath: string;
-const originalCwd = process.cwd();
-const originalLog = console.log;
+testCli({
+  runCommand: (args: string[]) => Dep.run(args),
+  name: 'nbx add:dep',
+  defaultArgs: ['--no-spinner'],
+  tests: [
+    {
+      name: 'fail if no package.json found',
+      runner: expectFailCli({
+        args: ['chalk'],
+        errorMessage: 'There is no package.json not found in the current folder',
+        before: async () => {
+          filesystem.remove('package.json');
+        },
+      }),
+    },
+    {
+      name: 'fail if dependancy is already in package.json',
+      runner: expectFailCli({
+        args: ['chalk'],
+        errorMessage: 'chalk is already installed in this project',
+        before: async () => {
+          await createDefaultNbxConfig();
+          filesystem.write('package.json', { dependencies: { chalk: '2.3.2' } });
+        },
+      }),
+    },
+    {
+      name: 'fail if dev dependancy is already in package.json',
+      runner: expectFailCli({
+        args: ['chalk', '-D'],
+        errorMessage: 'chalk is already installed in this project',
+        before: async () => {
+          await createDefaultNbxConfig();
+          filesystem.write('package.json', { devDependencies: { chalk: '2.3.2' } });
+        },
+      }),
+    },
+    {
+      name: 'work with dependency',
+      runner: expectGitCommits({
+        args: ['chalk'],
+        expectGitLog: async () => {
+          const latestChalk = await latestVersion('chalk');
+          return [
+            `:heavy_plus_sign: add chalk@${latestChalk} as a dependency`,
+            'M\tpackage.json',
+            'M\tyarn.lock',
+          ];
+        },
+        checks: async () => {
+          const latestChalk = await latestVersion('chalk');
 
-beforeEach(async () => {
-  consoleLogOutput = [];
-  console.log = (x: any) => consoleLogOutput.push(stripANSI(x));
+          const packageJson = filesystem.read('package.json', 'json');
+          expect(packageJson).toStrictEqual({
+            dependencies: {
+              chalk: latestChalk,
+            },
+          });
+        },
+      }),
+    },
+    {
+      name: 'work with a dev dependency',
+      runner: expectGitCommits({
+        args: ['chalk', '-D'],
+        expectGitLog: async () => {
+          const latestChalk = await latestVersion('chalk');
+          return [
+            `:heavy_plus_sign: add chalk@${latestChalk} as a dev dependency`,
+            'M\tpackage.json',
+            'M\tyarn.lock',
+          ];
+        },
+        checks: async () => {
+          const latestChalk = await latestVersion('chalk');
 
-  const tmpDirName = `${new Date().getTime()}-${Math.random() * 100}-add-nbx-test`;
-  execPath = filesystem.path('/', 'tmp', tmpDirName);
-  filesystem.dir(execPath);
-  process.chdir(execPath);
-});
-afterEach(() => {
-  console.log = originalLog;
-  process.chdir(originalCwd);
-  jest.restoreAllMocks();
-  filesystem.remove(execPath);
-});
-
-const initWithConfigAndCommit = async () => {
-  await system.run('git init');
-  filesystem.write('.nbxrc', { git: { user: 'aaa', email: 'bbb' } });
-  filesystem.write('package.json', {});
-  await system.run('touch yarn.lock');
-  await system.run('echo node_modules > .gitignore');
-  await system.run('git add * .nbxrc .gitignore');
-  try {
-    await system.run('git config user.email "you@example.com"');
-    await system.run('git config user.name "Your Name"');
-  } catch {}
-  await system.run('git commit -m "init state"');
-};
-
-describe('dep', () => {
-  it('should print help correctly', async () => {
-    try {
-      await Dep.run(['-h']);
-    } catch {}
-    expect(consoleLogOutput).toMatchSnapshot();
-  });
-  it('should fail if no package.json found', async () => {
-    expect.assertions(1);
-    try {
-      filesystem.remove('package.json');
-      await Dep.run(['chalk', '--no-spinner']);
-      // eslint-disable-next-line unicorn/catch-error-name
-    } catch (e) {
-      expect(e).toMatchSnapshot();
-    }
-  });
-  it('should fail if dependancy is already in package.json', async () => {
-    expect.assertions(1);
-    try {
-      filesystem.write('package.json', { dependencies: { chalk: '2.3.2' } });
-      await Dep.run(['chalk', '--no-spinner']);
-      // eslint-disable-next-line unicorn/catch-error-name
-    } catch (e) {
-      expect(e).toMatchSnapshot();
-    }
-  });
-  it('should fail if dev dependancy is already in package.json', async () => {
-    expect.assertions(1);
-    try {
-      filesystem.write('package.json', { devDependencies: { chalk: '2.3.2' } });
-      await Dep.run(['chalk', '--dev', '--no-spinner']);
-      // eslint-disable-next-line unicorn/catch-error-name
-    } catch (e) {
-      expect(e).toMatchSnapshot();
-    }
-  });
-
-  it('should work with dependency', async () => {
-    await initWithConfigAndCommit();
-    const latestChalk = await latestVersion('chalk');
-
-    await Dep.run(['chalk', '--no-spinner']);
-
-    const packageJson = filesystem.read('package.json', 'json');
-    expect(consoleLogOutput).toMatchSnapshot();
-    expect(packageJson).toStrictEqual({
-      dependencies: {
-        chalk: latestChalk,
-      },
-    });
-    const after = await system.run('git log --name-status  --format="%s"');
-    const afterSlitted = after
-      .split('\n')
-      .map(val => val.trim())
-      .map(val => stripANSI(val))
-      .filter(val => val !== '');
-
-    expect(afterSlitted).toStrictEqual([
-      `:heavy_plus_sign: add chalk@${latestChalk} as a dependency`,
-      'M\tpackage.json',
-      'M\tyarn.lock',
-      'init state',
-      'A\t.gitignore',
-      'A\t.nbxrc',
-      'A\tpackage.json',
-      'A\tyarn.lock',
-    ]);
-  });
-
-  it('should work with a dev dependency', async () => {
-    await initWithConfigAndCommit();
-    const latestChalk = await latestVersion('chalk');
-
-    await Dep.run(['chalk', '-D', '--no-spinner']);
-
-    const packageJson = filesystem.read('package.json', 'json');
-    expect(consoleLogOutput).toMatchSnapshot();
-    expect(packageJson).toStrictEqual({
-      devDependencies: {
-        chalk: latestChalk,
-      },
-    });
-    const after = await system.run('git log --name-status  --format="%s"');
-    const afterSlitted = after
-      .split('\n')
-      .map(val => val.trim())
-      .map(val => stripANSI(val))
-      .filter(val => val !== '');
-
-    expect(afterSlitted).toStrictEqual([
-      `:heavy_plus_sign: add chalk@${latestChalk} as a dev dependency`,
-      'M\tpackage.json',
-      'M\tyarn.lock',
-      'init state',
-      'A\t.gitignore',
-      'A\t.nbxrc',
-      'A\tpackage.json',
-      'A\tyarn.lock',
-    ]);
-  });
+          const packageJson = filesystem.read('package.json', 'json');
+          expect(packageJson).toStrictEqual({
+            devDependencies: {
+              chalk: latestChalk,
+            },
+          });
+        },
+      }),
+    },
+  ],
 });
diff --git a/src/tests/test-helpers.spec.ts b/src/tests/test-helpers.spec.ts
new file mode 100644
index 0000000..dcb1c26
--- /dev/null
+++ b/src/tests/test-helpers.spec.ts
@@ -0,0 +1,153 @@
+import { Command } from '@oclif/command';
+const stripANSI = require('strip-ansi');
+import { filesystem, system } from 'gluegun';
+
+export type TestRun = (args: { exec: Function; defaultArgs?: string[] }) => Promise<any>;
+
+export interface TestCase {
+  name: string;
+  runner: TestRun;
+}
+
+export interface TestCliParams {
+  tests: TestCase[];
+  runCommand: (args: string[]) => PromiseLike<any>;
+  name: string;
+  defaultArgs?: string[];
+}
+
+export const createDefaultNbxConfig = async () => {
+  filesystem.write('.nbxrc', { git: { user: 'aaa', email: 'bbb' } });
+};
+
+export const initWithConfigAndCommit = async () => {
+  await system.run('git init');
+  await createDefaultNbxConfig();
+  filesystem.write('package.json', {});
+  await system.run('touch yarn.lock');
+  await system.run('echo node_modules > .gitignore');
+  await system.run('git add * .nbxrc .gitignore');
+  try {
+    await system.run('git config user.email "you@example.com"');
+    await system.run('git config user.name "Your Name"');
+  } catch {}
+  await system.run('git commit -m "init state"');
+};
+
+export const expectGitCommits = ({
+  before,
+  args,
+  expectGitLog,
+  checks,
+}: {
+  args: string[];
+  expectGitLog: string[] | (() => Promise<any>);
+  before?: () => Promise<any>;
+  checks?: () => Promise<any>;
+}): TestRun => async ({ exec, defaultArgs = [] }) => {
+  await initWithConfigAndCommit();
+  await before?.();
+
+  try {
+    await exec([...args, ...defaultArgs]);
+  } catch {
+    fail('Cli errored');
+  }
+
+  const after = await system.run('git log --name-status  --format="%s"');
+  const afterSlitted = after
+    .split('\n')
+    .map(val => val.trim())
+    .map(val => stripANSI(val))
+    .filter(val => val !== '');
+
+  if (expectGitLog instanceof Function) {
+    expect(afterSlitted).toStrictEqual([
+      ...(await expectGitLog()),
+      'init state',
+      'A\t.gitignore',
+      'A\t.nbxrc',
+      'A\tpackage.json',
+      'A\tyarn.lock',
+    ]);
+  } else {
+    expect(afterSlitted).toStrictEqual([
+      ...expectGitLog,
+      'init state',
+      'A\t.gitignore',
+      'A\t.nbxrc',
+      'A\tpackage.json',
+      'A\tyarn.lock',
+    ]);
+  }
+
+  await checks?.();
+};
+
+export const expectFailCli = ({
+  assertions = 4,
+  before,
+  args,
+  errorMessage,
+}: {
+  assertions?: number;
+  before?: () => Promise<any>;
+  args: string[];
+  errorMessage: string;
+}): TestRun => async ({ exec, defaultArgs = [] }) => {
+  expect.assertions(assertions);
+  try {
+    await before?.();
+
+    await exec([...args, ...defaultArgs]);
+    // eslint-disable-next-line unicorn/catch-error-name
+  } catch (e) {
+    expect(e).toBeDefined();
+    expect(e.message).toBeDefined();
+    expect(e.message).toBe(errorMessage);
+  }
+};
+
+export const testCli = ({ tests, runCommand, name, defaultArgs }: TestCliParams) => {
+  /* eslint-disable no-console,max-nested-callbacks,@typescript-eslint/ban-ts-ignore */
+  let consoleLogOutput: string[];
+  let execPath: string;
+  const originalCwd = process.cwd();
+  const originalLog = console.log;
+
+  beforeEach(async () => {
+    consoleLogOutput = [];
+    console.log = (x: any) => consoleLogOutput.push(stripANSI(x));
+
+    const tmpDirName = `${new Date().getTime()}-${Math.random() * 100}-add-nbx-test`;
+    execPath = filesystem.path('/', 'tmp', tmpDirName);
+    filesystem.dir(execPath);
+    process.chdir(execPath);
+  });
+  afterEach(() => {
+    console.log = originalLog;
+    process.chdir(originalCwd);
+    jest.restoreAllMocks();
+    filesystem.remove(execPath);
+  });
+
+  describe(name, () => {
+    it('should print help correctly', async () => {
+      try {
+        await runCommand(['-h']);
+      } catch {}
+      expect(consoleLogOutput).toMatchSnapshot();
+    });
+
+    tests.forEach(testCase => {
+      it(`should ${testCase.name}`, async () => {
+        await testCase.runner({ exec: runCommand, defaultArgs: defaultArgs });
+        expect(consoleLogOutput).toMatchSnapshot();
+      });
+    });
+  });
+};
+
+const testHelp = (command: Command) => {
+  it('');
+};