diff --git a/lib/project.js b/lib/project.js
index 7b0bacf..457d3ec 100644
--- a/lib/project.js
+++ b/lib/project.js
@@ -1,20 +1,38 @@
 'use strict'
 
 module.exports.Project = class Project {
+  /**
+   * Constructs a new Project instance.
+   *
+   * @param {object|string} proj - The project information. It can be a string in the format "repoOwner/repoName" or an object with the following properties:
+   * @param {string} [proj.repo] - The repository in the format "repoOwner/repoName".
+   * @param {string} [proj.repoOwner] - The owner of the repository.
+   * @param {string} [proj.repoName] - The name of the repository.
+   * @param {string} [proj.name] - The name of the project.
+   * @param {string} [proj.repoBranch] - The branch of the repository.
+   * @param {string} [proj.repoDirectory] - The directory of the repository.
+   */
   constructor (proj) {
     let repo
     let repoOwner
     let repoName
     if (typeof proj === 'string') {
       [repoOwner, repoName] = proj.split('/')
+
+      if (!repoOwner || !repoName) {
+        throw new Error('Invalid repo format. It should be in the format "repoOwner/repoName".')
+      }
+
       repo = proj
-    } else if (proj.repo && (!proj.repoOwner || !proj.repoName)) {
+    } else if (proj?.repo) {
       [repoOwner, repoName] = proj.repo.split('/')
       repo = proj.repo
       repoOwner = proj.repoOwner || repoOwner
       repoName = proj.repoName || repoName
-    } else if (!proj.repo && proj.repoOwner && proj.repoName) {
-      repo = `${proj.repoOwner}/${proj.repoName}`
+    } else {
+      if (proj?.repoOwner && proj?.repoName) {
+        repo = `${proj.repoOwner}/${proj.repoName}`
+      }
       repoOwner = proj.repoOwner
       repoName = proj.repoName
     }
diff --git a/test/models.test.js b/test/models.test.js
new file mode 100644
index 0000000..9e028c8
--- /dev/null
+++ b/test/models.test.js
@@ -0,0 +1,186 @@
+const assert = require('assert')
+const { Organization } = require('../lib/organization')
+const { Project } = require('../lib/project')
+const { Manifest, Packument } = require('../lib/npm')
+const { describe, it } = require('mocha')
+
+describe('Organization', function () {
+  it('should create an organization with a name string', function () {
+    const org = new Organization('TestOrg')
+    assert.strictEqual(org.name, 'TestOrg')
+    assert.strictEqual(org.displayName, 'TestOrg')
+    assert.strictEqual(org.url, undefined)
+  })
+
+  it('should create an organization with an object', function () {
+    const org = new Organization({ name: 'TestOrg', displayName: 'Test Organization', url: 'http://test.org' })
+    assert.strictEqual(org.name, 'TestOrg')
+    assert.strictEqual(org.displayName, 'Test Organization')
+    assert.strictEqual(org.url, 'http://test.org')
+  })
+
+  it('should use name as displayName if displayName is not provided', function () {
+    const org = new Organization({ name: 'TestOrg' })
+    assert.strictEqual(org.name, 'TestOrg')
+    assert.strictEqual(org.displayName, 'TestOrg')
+    assert.strictEqual(org.url, undefined)
+  })
+
+  it('should handle empty object input', function () {
+    const org = new Organization({})
+    assert.strictEqual(org.name, undefined)
+    assert.strictEqual(org.displayName, undefined)
+    assert.strictEqual(org.url, undefined)
+  })
+
+  it('should handle no input', function () {
+    const org = new Organization()
+    assert.strictEqual(org.name, undefined)
+    assert.strictEqual(org.displayName, undefined)
+    assert.strictEqual(org.url, undefined)
+  })
+})
+
+describe('Project', () => {
+  it('should initialize with a string repo', () => {
+    const proj = new Project('owner/repo')
+    assert.strictEqual(proj.repo, 'owner/repo')
+    assert.strictEqual(proj.repoOwner, 'owner')
+    assert.strictEqual(proj.repoName, 'repo')
+    assert.strictEqual(proj.name, 'owner/repo')
+    assert.strictEqual(proj.repoBranch, undefined)
+    assert.strictEqual(proj.repoDirectory, '/')
+    assert.strictEqual(proj.packageName, null)
+  })
+
+  it('should throw an error if the repo format is invalid', () => {
+    assert.throws(() => new Project('owner'), {
+      name: 'Error',
+      message: 'Invalid repo format. It should be in the format "repoOwner/repoName".'
+    })
+  })
+
+  it('should initialize with an object containing repo', () => {
+    const proj = new Project({ repo: 'owner/repo' })
+    assert.strictEqual(proj.repo, 'owner/repo')
+    assert.strictEqual(proj.repoOwner, 'owner')
+    assert.strictEqual(proj.repoName, 'repo')
+    assert.strictEqual(proj.name, 'owner/repo')
+    assert.strictEqual(proj.repoBranch, undefined)
+    assert.strictEqual(proj.repoDirectory, '/')
+    assert.strictEqual(proj.packageName, null)
+  })
+
+  it('should initialize with an object containing repoOwner and repoName', () => {
+    const proj = new Project({ repoOwner: 'owner', repoName: 'repo' })
+    assert.strictEqual(proj.repo, 'owner/repo')
+    assert.strictEqual(proj.repoOwner, 'owner')
+    assert.strictEqual(proj.repoName, 'repo')
+    assert.strictEqual(proj.name, 'owner/repo')
+    assert.strictEqual(proj.repoBranch, undefined)
+    assert.strictEqual(proj.repoDirectory, '/')
+    assert.strictEqual(proj.packageName, null)
+  })
+
+  it('should initialize with an object containing only repoName', () => {
+    const proj = new Project({ repoName: 'repo' })
+    assert.strictEqual(proj.repo, undefined)
+    assert.strictEqual(proj.repoOwner, undefined)
+    assert.strictEqual(proj.repoName, 'repo')
+    assert.strictEqual(proj.name, undefined)
+    assert.strictEqual(proj.repoBranch, undefined)
+    assert.strictEqual(proj.repoDirectory, '/')
+    assert.strictEqual(proj.packageName, null)
+  })
+
+  it('should initialize with an object containing all properties', () => {
+    const proj = new Project({
+      name: 'customName',
+      repo: 'owner/repo',
+      repoBranch: 'main',
+      repoDirectory: '/src'
+    })
+    assert.strictEqual(proj.repo, 'owner/repo')
+    assert.strictEqual(proj.repoOwner, 'owner')
+    assert.strictEqual(proj.repoName, 'repo')
+    assert.strictEqual(proj.name, 'customName')
+    assert.strictEqual(proj.repoBranch, 'main')
+    assert.strictEqual(proj.repoDirectory, '/src')
+    assert.strictEqual(proj.packageName, null)
+  })
+})
+
+describe('Manifest', function () {
+  it('should correctly initialize with given manifest data', function () {
+    const manifestData = {
+      name: 'test-package',
+      version: '1.0.0',
+      dependencies: { dep1: '^1.0.0' },
+      optionalDependencies: { optDep1: '^1.0.0' },
+      devDependencies: { devDep1: '^1.0.0' },
+      peerDependencies: { peerDep1: '^1.0.0' },
+      bundleDependencies: { bundleDep1: '^1.0.0' },
+      bin: { bin1: 'bin1.js' }
+    }
+
+    const manifest = new Manifest(manifestData)
+
+    assert.strictEqual(manifest.name, manifestData.name)
+    assert.strictEqual(manifest.version, manifestData.version)
+    assert.deepStrictEqual(manifest.dependencies, manifestData.dependencies)
+    assert.deepStrictEqual(manifest.optionalDependencies, manifestData.optionalDependencies)
+    assert.deepStrictEqual(manifest.devDependencies, manifestData.devDependencies)
+    assert.deepStrictEqual(manifest.peerDependencies, manifestData.peerDependencies)
+    assert.deepStrictEqual(manifest.bundleDependencies, manifestData.bundleDependencies)
+    assert.deepStrictEqual(manifest.bin, manifestData.bin)
+  })
+
+  it('should handle missing optional fields', function () {
+    const manifestData = {
+      name: 'test-package',
+      version: '1.0.0'
+    }
+
+    const manifest = new Manifest(manifestData)
+
+    assert.strictEqual(manifest.name, manifestData.name)
+    assert.strictEqual(manifest.version, manifestData.version)
+    assert.strictEqual(manifest.dependencies, undefined)
+    assert.strictEqual(manifest.optionalDependencies, undefined)
+    assert.strictEqual(manifest.devDependencies, undefined)
+    assert.strictEqual(manifest.peerDependencies, undefined)
+    assert.strictEqual(manifest.bundleDependencies, undefined)
+    assert.strictEqual(manifest.bin, undefined)
+  })
+})
+
+describe('Packument', function () {
+  it('should create an instance with the correct properties', function () {
+    const packumentData = {
+      name: 'example-package',
+      distTags: { latest: '1.0.0' },
+      modified: '2023-10-01T00:00:00.000Z',
+      versions: { '1.0.0': {} }
+    }
+
+    const packument = new Packument(packumentData)
+
+    assert.strictEqual(packument.name, 'example-package')
+    assert.deepStrictEqual(packument.distTags, { latest: '1.0.0' })
+    assert.strictEqual(packument.modified, '2023-10-01T00:00:00.000Z')
+    assert.deepStrictEqual(packument.versions, { '1.0.0': {} })
+  })
+
+  it('should handle dist-tags correctly', function () {
+    const packumentData = {
+      name: 'example-package',
+      'dist-tags': { latest: '1.0.0' },
+      modified: '2023-10-01T00:00:00.000Z',
+      versions: { '1.0.0': {} }
+    }
+
+    const packument = new Packument(packumentData)
+
+    assert.deepStrictEqual(packument.distTags, { latest: '1.0.0' })
+  })
+})