diff --git a/.github/workflows/nodejs.yml b/.github/workflows/nodejs.yml
index f00cb63..a7637e0 100644
--- a/.github/workflows/nodejs.yml
+++ b/.github/workflows/nodejs.yml
@@ -8,7 +8,7 @@ jobs:
 
     strategy:
       matrix:
-        node-version: [10.x, 12.x, 14.x]
+        node-version: [12.x, 14.x, 16.x]
 
     steps:
     - uses: actions/checkout@v2
diff --git a/.github/workflows/npmpublish.yml b/.github/workflows/npmpublish.yml
index 51edeb1..50dfaa4 100644
--- a/.github/workflows/npmpublish.yml
+++ b/.github/workflows/npmpublish.yml
@@ -11,7 +11,7 @@ jobs:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 16
       - run: npm install
       - run: npm test
 
@@ -22,7 +22,7 @@ jobs:
       - uses: actions/checkout@v1
       - uses: actions/setup-node@v1
         with:
-          node-version: 12
+          node-version: 16
           registry-url: https://registry.npmjs.org/
       - run: npm install
       - run: npm publish
diff --git a/.gitignore b/.gitignore
index 25ae498..46c6f64 100644
--- a/.gitignore
+++ b/.gitignore
@@ -2,3 +2,6 @@ coverage
 node_modules
 package-lock.json
 .nyc_output
+
+test/types/*.js
+test/types/*.map
diff --git a/.travis.yml b/.travis.yml
index b0ce4a8..d5e8a8b 100644
--- a/.travis.yml
+++ b/.travis.yml
@@ -2,7 +2,6 @@ language: node_js
 node_js:
   - "node"
   - "lts/*"
-  - "10"
 
 after_success:
   - npm install coveralls
diff --git a/index.js b/index.js
index 7ca01ec..617a4c9 100644
--- a/index.js
+++ b/index.js
@@ -457,6 +457,10 @@ class SSHConfig extends Array {
         config.push(node)
         config = node.config = new SSHConfig()
       }
+      else if (node.type === DIRECTIVE && !node.param) {
+        // blank lines at file end
+        config[config.length - 1].after += node.before
+      }
       else {
         config.push(node)
       }
diff --git a/package.json b/package.json
index fd5c06c..3c13968 100644
--- a/package.json
+++ b/package.json
@@ -13,15 +13,19 @@
     "types"
   ],
   "devDependencies": {
+    "@types/mocha": "^9.1.0",
+    "@types/node": "^17.0.23",
     "eslint": "^7.17.0",
     "heredoc": "^1.3.1",
     "mocha": "^8.2.1",
-    "nyc": "^15.1.0"
+    "nyc": "^15.1.0",
+    "typescript": "^4.6.3"
   },
   "scripts": {
     "lint": "eslint .",
-    "test": "mocha --exit",
-    "test:coverage": "nyc mocha --exit && nyc report --reporter=lcov"
+    "pretest": "tsc",
+    "test": "NODE_OPTIONS=--enable-source-maps mocha --exit --recursive",
+    "test:coverage": "nyc mocha --exit --recursive && nyc report --reporter=lcov"
   },
   "engine": {
     "node": ">= 10.0.0"
diff --git a/test/types/ssh-config.test.ts b/test/types/ssh-config.test.ts
new file mode 100644
index 0000000..1728228
--- /dev/null
+++ b/test/types/ssh-config.test.ts
@@ -0,0 +1,49 @@
+import SSHConfig from '../..'
+import { strict as assert } from 'assert'
+
+describe('SSHConfig (TypeScript)', function() {
+  let config: SSHConfig
+
+  beforeEach(function() {
+    config = SSHConfig.parse(`
+      IdentityFile ~/.ssh/id_rsa
+
+      Host ness
+        HostName lochness.com
+    `)
+  })
+
+  it('.find(line => boolean)', function() {
+    const section = config.find(line => line.type === SSHConfig.DIRECTIVE && line.param === 'Host' && line.value === 'ness')
+    assert.equal(section.type, SSHConfig.DIRECTIVE)
+    assert.equal(section.param, 'Host')
+    assert.equal(section.value, 'ness')
+  })
+
+  it('.find({ Host })', function() {
+    const section = config.find({ Host: 'ness' })
+    assert.equal(section.type, SSHConfig.DIRECTIVE)
+    if ('config' in section) {
+      assert.deepEqual(SSHConfig.stringify(section.config).trim(), 'HostName lochness.com')
+    }
+  })
+
+  it('.compute(host)', function() {
+    const result = config.compute('ness');
+    console.log(result)
+    assert.deepEqual(result, {
+      Host: 'ness',
+      HostName: 'lochness.com',
+      IdentityFile: [ '~/.ssh/id_rsa' ],
+    })
+  })
+
+  it('.stringify(config)', function() {
+    assert.deepEqual(config.toString(), `
+      IdentityFile ~/.ssh/id_rsa
+
+      Host ness
+        HostName lochness.com
+    `)
+  })
+})
diff --git a/test/test.glob.js b/test/unit/glob.test.js
similarity index 97%
rename from test/test.glob.js
rename to test/unit/glob.test.js
index d26ccc4..23fcc50 100644
--- a/test/test.glob.js
+++ b/test/unit/glob.test.js
@@ -2,7 +2,7 @@
 
 const assert = require('assert').strict || require('assert')
 
-const glob = require('../src/glob')
+const glob = require('../../src/glob')
 
 
 describe('glob', function() {
diff --git a/test/test.parse.js b/test/unit/parse.test.js
similarity index 96%
rename from test/test.parse.js
rename to test/unit/parse.test.js
index a0383b1..d9129f2 100644
--- a/test/test.parse.js
+++ b/test/unit/parse.test.js
@@ -5,17 +5,17 @@ const assert = require('assert').strict || require('assert')
 const fs = require('fs')
 const heredoc = require('heredoc').strip
 const path = require('path')
-const SSHConfig = require('..')
+const SSHConfig = require('../..')
 
 const { parse, COMMENT, DIRECTIVE } = SSHConfig
 
-function readFile(fpath) {
-  return fs.readFileSync(path.join(__dirname, fpath), 'utf-8')
-    .replace(/\r\n/g, '\n')
+function readFile(fname) {
+  const fpath = path.join(__dirname, '..', fname)
+  return fs.readFileSync(fpath, 'utf-8').replace(/\r\n/g, '\n')
 }
 
 describe('parse', function() {
-  it('.parse simple config', function() {
+  it('.parse simple config', async function() {
     const config = parse(readFile('fixture/config'))
 
     assert.equal(config[0].param, 'ControlMaster')
diff --git a/test/test.ssh-config.js b/test/unit/ssh-config.test.js
similarity index 96%
rename from test/test.ssh-config.js
rename to test/unit/ssh-config.test.js
index b3e3082..83ccc61 100644
--- a/test/test.ssh-config.js
+++ b/test/unit/ssh-config.test.js
@@ -5,17 +5,17 @@ const fs = require('fs')
 const path = require('path')
 const heredoc = require('heredoc').strip
 
-const SSHConfig = require('..')
+const SSHConfig = require('../..')
 
 const { DIRECTIVE } = SSHConfig
 
-function readFile(fpath) {
-  return fs.readFileSync(path.join(__dirname, fpath), 'utf-8')
-    .replace(/\r\n/g, '\n')
+function readFile(fname) {
+  const fpath = path.join(__dirname, '..', fname)
+  return fs.readFileSync(fpath, 'utf-8').replace(/\r\n/g, '\n')
 }
 
 describe('SSHConfig', function() {
-  it('.compute by Host', function() {
+  it('.compute by Host', async function() {
     const config = SSHConfig.parse(readFile('fixture/config'))
     const opts = config.compute('tahoe2')
 
@@ -91,18 +91,18 @@ describe('SSHConfig', function() {
     }
   })
 
-  it('.find with nothing shall yield error', function() {
+  it('.find with nothing shall yield error', async function() {
     const config = SSHConfig.parse(readFile('fixture/config'))
     assert.throws(function() { config.find() })
     assert.throws(function() { config.find({}) })
   })
 
-  it('.find shall return null if nothing were found', function() {
+  it('.find shall return null if nothing were found', async function() {
     const config = SSHConfig.parse(readFile('fixture/config'))
     assert(config.find({ Host: 'not.exist' }) == null)
   })
 
-  it('.find by Host', function() {
+  it('.find by Host', async function() {
     const config = SSHConfig.parse(readFile('fixture/config'))
 
     assert.deepEqual(config.find({ Host: 'tahoe1' }), {
@@ -147,7 +147,7 @@ describe('SSHConfig', function() {
     })
   })
 
-  it('.remove by Host', function() {
+  it('.remove by Host', async function() {
     const config = SSHConfig.parse(readFile('fixture/config'))
     const length = config.length
 
diff --git a/test/test.stringify.js b/test/unit/stringify.test.js
similarity index 94%
rename from test/test.stringify.js
rename to test/unit/stringify.test.js
index dd557eb..bc5d8e1 100644
--- a/test/test.stringify.js
+++ b/test/unit/stringify.test.js
@@ -4,16 +4,16 @@ const assert = require('assert').strict || require('assert')
 const fs = require('fs')
 const heredoc = require('heredoc').strip
 const path = require('path')
-const SSHConfig = require('..')
+const SSHConfig = require('../..')
 const { parse, stringify } = SSHConfig
 
-function readFile(fpath) {
-  return fs.readFileSync(path.join(__dirname, fpath), 'utf-8')
-    .replace(/\r\n/g, '\n')
+function readFile(fname) {
+  const fpath = path.join(__dirname, '..', fname)
+  return fs.readFileSync(fpath, 'utf-8').replace(/\r\n/g, '\n')
 }
 
 describe('stringify', function() {
-  it('.stringify the parsed object back to string', function() {
+  it('.stringify the parsed object back to string', async function() {
     const fixture = readFile('fixture/config')
     const config = parse(fixture)
     assert.equal(fixture, stringify(config))
diff --git a/tsconfig.json b/tsconfig.json
new file mode 100644
index 0000000..dfd42bb
--- /dev/null
+++ b/tsconfig.json
@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "target": "es2018",
+    "moduleResolution": "Node",
+    "module": "CommonJS",
+    "experimentalDecorators": true,
+    "emitDecoratorMetadata": true,
+    "esModuleInterop": true,
+    "sourceMap": true
+  }
+}
diff --git a/types/index.d.ts b/types/index.d.ts
index 019a304..f941180 100644
--- a/types/index.d.ts
+++ b/types/index.d.ts
@@ -13,7 +13,7 @@ interface Directive {
 }
 
 interface Section extends Directive {
-  config: SSHConfig;
+  config: SSHConfig<Line>;
 }
 
 interface Comment {
@@ -21,21 +21,26 @@ interface Comment {
   content: string;
 }
 
-type Line = Directive | Comment;
+type Line = Section | Directive | Comment;
 
-export default class SSHConfig extends Array {
-  static parse(text: string): SSHConfig;
-  static stringify(config: SSHConfig): string;
+declare class SSHConfig<T> extends Array<T> {
+  static parse(text: string): SSHConfig<Line>;
+  static stringify(config: SSHConfig<Line>): string;
+
+  static DIRECTIVE: ELine.DIRECTIVE;
+  static COMMENT: ELine.COMMENT;
 
   toString(): string;
 
   compute(host: string): Record<string, string>;
 
-  find(predicate: (value: any, index: number, obj: any[]) => any);
+  find<T>(this: SSHConfig<T>, predicate: (line: T, index: number, config: T[]) => boolean): T;
   find(options: Record<string, string>): Line | Section;
 
   remove(options: Record<string, string>): Line | Section;
 
-  append(options: Record<string, string>): SSHConfig;
-  prepend(options: Record<string, string>): SSHConfig;
+  append(options: Record<string, string>): SSHConfig<Line>;
+  prepend(options: Record<string, string>): SSHConfig<Line>;
 }
+
+export default class extends SSHConfig<Line> {}
diff --git a/types/ssh-config-tests.ts b/types/ssh-config-tests.ts
deleted file mode 100644
index 66128b3..0000000
--- a/types/ssh-config-tests.ts
+++ /dev/null
@@ -1,10 +0,0 @@
-import SSHConfig from './index';
-
-const config = SSHConfig.parse(`
-IdentityFile ~/.ssh/id_rsa
-
-Host ness
-  HostName lochness.com
-`);
-
-console.log(config.toString());