diff --git a/coverage.sh b/coverage.sh
new file mode 100755
index 0000000..1412c6a
--- /dev/null
+++ b/coverage.sh
@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+rm -fr /cov_profile/
+deno test --allow-all --coverage=cov_profile
+deno coverage cov_profile --lcov > cov_profile/cov_profile.lcov
+genhtml -o cov_profile cov_profile/cov_profile.lcov
+rm cov_profile/*.json
+open cov_profile/index.html
+
+
diff --git a/justfile b/justfile
index 8dbe4f0..636269c 100644
--- a/justfile
+++ b/justfile
@@ -48,7 +48,7 @@ deno-check:
 
 # Test with deno
 deno-test:
-	deno test --allow-all
+	deno test --allow-all --unstable
 
 # Create test coverage report with deno
 deno-coverage:
diff --git a/src/bun/ffi.ts b/src/bun/ffi.ts
index 46d6d9f..95314b6 100644
--- a/src/bun/ffi.ts
+++ b/src/bun/ffi.ts
@@ -42,6 +42,7 @@ const BunFFI: IFFI = {
 	tcsetattr,
 	cfmakeraw,
 	getPointer: ptr,
+	close: cStdLib.close,
 };
 
 export default BunFFI;
diff --git a/src/bun/file_io.ts b/src/bun/file_io.ts
index 068ec52..2954de1 100644
--- a/src/bun/file_io.ts
+++ b/src/bun/file_io.ts
@@ -1,9 +1,9 @@
-import { IFIO } from '../common/runtime.ts';
+import { IFileIO } from '../common/runtime.ts';
 
 import { appendFileSync, readFileSync } from 'node:fs';
 import { appendFile } from 'node:fs/promises';
 
-const BunFileIO: IFIO = {
+const BunFileIO: IFileIO = {
 	openFile: async (path: string): Promise<string> => {
 		const file = await Bun.file(path);
 		return await file.text();
diff --git a/src/bun/terminal_io.ts b/src/bun/terminal_io.ts
index 129bef5..5c962e0 100644
--- a/src/bun/terminal_io.ts
+++ b/src/bun/terminal_io.ts
@@ -4,6 +4,11 @@
 import { ITerminal, ITerminalSize } from '../common/mod.ts';
 import Ansi from '../common/ansi.ts';
 
+const defaultTerminalSize: ITerminalSize = {
+	rows: 24,
+	cols: 80,
+};
+
 const BunTerminalIO: ITerminal = {
 	// Deno only returns arguments passed to the script, so
 	// remove the bun runtime executable, and entry script arguments
@@ -32,8 +37,8 @@ const BunTerminalIO: ITerminal = {
 			const rawCode = (new TextDecoder()).decode(chunk);
 			const res = rawCode.trim().replace(/^.\[([0-9]+;[0-9]+)R$/, '$1');
 			const [srows, scols] = res.split(';');
-			const rows = parseInt(srows, 10);
-			const cols = parseInt(scols, 10);
+			const rows = parseInt(srows, 10) ?? 24;
+			const cols = parseInt(scols, 10) ?? 80;
 
 			// Clear the screen
 			await write(Ansi.ClearScreen + Ansi.ResetCursor);
@@ -44,10 +49,7 @@ const BunTerminalIO: ITerminal = {
 			};
 		}
 
-		return {
-			rows: 24,
-			cols: 80,
-		};
+		return defaultTerminalSize;
 	},
 	writeStdout: async function write(s: string): Promise<void> {
 		const buffer = new TextEncoder().encode(s);
diff --git a/src/common/ansi.ts b/src/common/ansi.ts
index 7698c36..ab59288 100644
--- a/src/common/ansi.ts
+++ b/src/common/ansi.ts
@@ -43,11 +43,13 @@ export const Ansi = {
 	moveCursorDown: (row: number): string => ANSI_PREFIX + `${row}B`,
 };
 
-const decoder = new TextDecoder();
-
-export function readKey(raw: Uint8Array): string {
-	const parsed = decoder.decode(raw);
-
+/**
+ * Convert input from ANSI escape sequences into a form
+ * that can be more easily mapped to editor commands
+ *
+ * @param parsed - the decoded chunk of input
+ */
+export function readKey(parsed: string): string {
 	// Return the input if it's unambiguous
 	if (parsed in KeyCommand) {
 		return parsed;
diff --git a/src/common/ansi_test.ts b/src/common/ansi_test.ts
new file mode 100644
index 0000000..f466eb0
--- /dev/null
+++ b/src/common/ansi_test.ts
@@ -0,0 +1,33 @@
+import { getTestRunner } from './mod.ts';
+import Ansi, { KeyCommand, readKey } from './ansi.ts';
+
+getTestRunner().then((t) => {
+	t.test('Ansi.moveCursor', () => {
+		t.assertEquals(Ansi.moveCursor(1, 2), '\x1b[2;3H');
+	});
+
+	t.test('Ansi.moveCursorForward', () => {
+		t.assertEquals(Ansi.moveCursorForward(2), '\x1b[2C');
+	});
+
+	t.test('Ansi.moveCursorDown', () => {
+		t.assertEquals(Ansi.moveCursorDown(7), '\x1b[7B');
+	});
+
+	t.test('readKey', () => {
+		// Ignore unhandled escape sequences
+		t.assertEquals(readKey('\x1b[]'), '\x1b[]');
+
+		// Pass explicitly mapped values right through
+		t.assertEquals(readKey(KeyCommand.ArrowUp), KeyCommand.ArrowUp);
+		t.assertEquals(readKey(KeyCommand.Home), KeyCommand.Home);
+
+		['\x1bOH', '\x1b[7~', '\x1b[1~', '\x1b[H'].forEach((code) => {
+			t.assertEquals(readKey(code), KeyCommand.Home);
+		});
+
+		['\x1bOF', '\x1b[8~', '\x1b[4~', '\x1b[F'].forEach((code) => {
+			t.assertEquals(readKey(code), KeyCommand.End);
+		});
+	});
+});
diff --git a/src/common/buffer.ts b/src/common/buffer.ts
index 22f4ccf..0b9b8e2 100644
--- a/src/common/buffer.ts
+++ b/src/common/buffer.ts
@@ -1,5 +1,5 @@
 import { strlen, truncate } from './utils.ts';
-import { getRuntime } from './runtime.ts';
+import { getRuntime, importForRuntime } from './runtime.ts';
 
 class Buffer {
 	#b = '';
@@ -12,7 +12,7 @@ class Buffer {
 	}
 
 	public appendLine(s = ''): void {
-		this.#b += (s ?? '') + '\r\n';
+		this.#b += s + '\r\n';
 	}
 
 	public clear(): void {
@@ -23,7 +23,7 @@ class Buffer {
 	 * Output the contents of the buffer into stdout
 	 */
 	public async flush() {
-		const { term } = await getRuntime();
+		const term = await importForRuntime('terminal_io');
 		await term.writeStdout(this.#b);
 		this.clear();
 	}
diff --git a/src/common/buffer_test.ts b/src/common/buffer_test.ts
new file mode 100644
index 0000000..488e762
--- /dev/null
+++ b/src/common/buffer_test.ts
@@ -0,0 +1,45 @@
+import { getTestRunner } from './runtime.ts';
+import Buffer from './buffer.ts';
+
+getTestRunner().then((t) => {
+	t.test('Buffer exists', () => {
+		const b = new Buffer();
+		t.assertInstanceOf(b, Buffer);
+		t.assertEquals(b.strlen(), 0);
+	});
+
+	t.test('Buffer.appendLine', () => {
+		const b = new Buffer();
+
+		// Carriage return and line feed
+		b.appendLine();
+		t.assertEquals(b.strlen(), 2);
+
+		b.clear();
+		t.assertEquals(b.strlen(), 0);
+
+		b.appendLine('foo');
+		t.assertEquals(b.strlen(), 5);
+	});
+
+	t.test('Buffer.append', () => {
+		const b = new Buffer();
+
+		b.append('foobar');
+		t.assertEquals(b.strlen(), 6);
+		b.clear();
+
+		b.append('foobar', 3);
+		t.assertEquals(b.strlen(), 3);
+	});
+
+	t.test('Buffer.flush', async () => {
+		const b = new Buffer();
+		b.append('foobarbaz');
+		t.assertEquals(b.strlen(), 9);
+
+		await b.flush();
+
+		t.assertEquals(b.strlen(), 0);
+	});
+});
diff --git a/src/common/editor.ts b/src/common/editor.ts
index 2a4c1f7..dddb71a 100644
--- a/src/common/editor.ts
+++ b/src/common/editor.ts
@@ -1,7 +1,7 @@
 import Ansi, { KeyCommand } from './ansi.ts';
 import Buffer from './buffer.ts';
 import Document from './document.ts';
-import { IPoint, ITerminalSize, VERSION } from './mod.ts';
+import { IPoint, ITerminalSize, logToFile, VERSION } from './mod.ts';
 import { ctrl_key } from './utils.ts';
 
 export class Editor {
@@ -152,12 +152,17 @@ export class Editor {
 
 	private drawFileRow(y: number): void {
 		const row = this.#document.row(y);
-		let len = row?.chars.length ?? 0;
+		if (row === null) {
+			logToFile(`Warning: trying to draw non-existent row '${y}'`);
+			return this.drawPlaceholderRow(y);
+		}
+
+		let len = row.chars.length ?? 0;
 		if (len > this.#screen.cols) {
 			len = this.#screen.cols;
 		}
 
-		this.#buffer.append(row!.toString(), len);
+		this.#buffer.append(row.toString(), len);
 		this.#buffer.appendLine(Ansi.ClearLine);
 	}
 
diff --git a/src/common/main.ts b/src/common/main.ts
index 152ecee..6666c93 100644
--- a/src/common/main.ts
+++ b/src/common/main.ts
@@ -4,6 +4,7 @@ import { getTermios } from './termios.ts';
 import { Editor } from './editor.ts';
 
 export async function main() {
+	const decoder = new TextDecoder();
 	const runTime = await getRuntime();
 	const { term, file, onExit, onEvent } = runTime;
 
@@ -12,14 +13,13 @@ export async function main() {
 	t.enableRawMode();
 	onExit(() => {
 		t.disableRawMode();
+		t.cleanup();
 	});
 
 	// Setup error handler to log to file
 	onEvent('error', (error) => {
 		t.disableRawMode();
-		if (error instanceof ErrorEvent) {
-			file.appendFileSync('./scroll.err', JSON.stringify(error, null, 2));
-		}
+		file.appendFileSync('./scroll.err', JSON.stringify(error, null, 2));
 	});
 
 	const terminalSize = await term.getTerminalSize();
@@ -39,7 +39,7 @@ export async function main() {
 	// The main event loop
 	for await (const chunk of term.inputLoop()) {
 		// Process input
-		const char = readKey(chunk);
+		const char = readKey(decoder.decode(chunk));
 		const shouldLoop = editor.processKeyPress(char);
 		if (!shouldLoop) {
 			return 0;
diff --git a/src/common/runtime.ts b/src/common/runtime.ts
index 5f6c004..2e88040 100644
--- a/src/common/runtime.ts
+++ b/src/common/runtime.ts
@@ -1,14 +1,25 @@
 import { getTermios } from './termios.ts';
+import { noop } from './utils.ts';
+import { ITestBase } from './types.ts';
 
-// ----------------------------------------------------------------------------
-// Runtime adapter interfaces
-// ----------------------------------------------------------------------------
 export enum RunTimeType {
 	Bun = 'bun',
 	Deno = 'deno',
 	Unknown = 'common',
 }
 
+// ----------------------------------------------------------------------------
+// Runtime adapter interfaces
+// ----------------------------------------------------------------------------
+
+/**
+ * The size of terminal in rows and columns
+ */
+export interface ITerminalSize {
+	rows: number;
+	cols: number;
+}
+
 /**
  * The native functions for getting/setting terminal settings
  */
@@ -33,14 +44,11 @@ export interface IFFI {
 	 */
 	// deno-lint-ignore no-explicit-any
 	getPointer(ta: any): unknown;
-}
 
-/**
- * The size of terminal in rows and columns
- */
-export interface ITerminalSize {
-	rows: number;
-	cols: number;
+	/**
+	 * Closes the FFI handle
+	 */
+	close(): void;
 }
 
 /**
@@ -51,10 +59,11 @@ export interface ITerminal {
 	 * The arguments passed to the program on launch
 	 */
 	argv: string[];
+
 	/**
 	 * The generator function returning chunks of input from the stdin stream
 	 */
-	inputLoop(): AsyncGenerator<Uint8Array, void, unknown>;
+	inputLoop(): AsyncGenerator<Uint8Array, void>;
 
 	/**
 	 * Get the size of the terminal
@@ -70,7 +79,7 @@ export interface ITerminal {
 /**
  * Runtime-specific file handling
  */
-export interface IFIO {
+export interface IFileIO {
 	openFile(path: string): Promise<string>;
 	openFileSync(path: string): string;
 	appendFile(path: string, contents: string): Promise<void>;
@@ -99,7 +108,7 @@ export interface IRuntime {
 	/**
 	 * Runtime-specific file system io
 	 */
-	file: IFIO;
+	file: IFileIO;
 
 	/**
 	 * Set up an event handler
@@ -132,6 +141,15 @@ export interface IRuntime {
 
 let scrollRuntime: IRuntime | null = null;
 
+export function logToFile(s: unknown) {
+	importForRuntime('file_io').then((f) => {
+		const raw = (typeof s === 'string') ? s : JSON.stringify(s, null, 2);
+		const output = raw + '\n';
+
+		f.appendFile('./scroll.log', output).then(noop);
+	});
+}
+
 /**
  * Kill program, displaying an error message
  * @param s
@@ -148,7 +166,7 @@ export function die(s: string | Error): void {
 /**
  * Determine which Typescript runtime we are operating under
  */
-export function getRuntimeType(): RunTimeType {
+export function runtimeType(): RunTimeType {
 	let runtime = RunTimeType.Unknown;
 
 	if ('Deno' in globalThis) {
@@ -166,7 +184,7 @@ export function getRuntimeType(): RunTimeType {
  */
 export async function getRuntime(): Promise<IRuntime> {
 	if (scrollRuntime === null) {
-		const runtime = getRuntimeType();
+		const runtime = runtimeType();
 		const path = `../${runtime}/mod.ts`;
 
 		const pkg = await import(path);
@@ -178,16 +196,30 @@ export async function getRuntime(): Promise<IRuntime> {
 	return Promise.resolve(scrollRuntime!);
 }
 
+/**
+ * Get the common test interface object
+ */
+export async function getTestRunner(): Promise<ITestBase> {
+	const runtime = runtimeType();
+	const path = `../${runtime}/test_base.ts`;
+	const pkg = await import(path);
+	if ('default' in pkg) {
+		return pkg.default;
+	}
+
+	return pkg;
+}
+
 /**
  * Import a runtime-specific module
  *
- * eg. to load "src/bun/mod.ts", if the runtime is bun,
+ * e.g. to load "src/bun/mod.ts", if the runtime is bun,
  * you can use like so `await importForRuntime('index')`;
  *
  * @param path - the path within the runtime module
  */
 export const importForRuntime = async (path: string) => {
-	const runtime = getRuntimeType();
+	const runtime = runtimeType();
 	const suffix = '.ts';
 	const base = `../${runtime}/`;
 
@@ -198,20 +230,10 @@ export const importForRuntime = async (path: string) => {
 	const cleanedPath = pathParts.join('/');
 	const importPath = base + cleanedPath + suffix;
 
-	return await import(importPath);
-};
-
-/**
- * Import the default export for a runtime-specific module
- * (this is just a simple wrapper of `importForRuntime`)
- *
- * @param path - the path within the runtime module
- */
-export const importDefaultForRuntime = async (path: string) => {
-	const pkg = await importForRuntime(path);
+	const pkg = await import(importPath);
 	if ('default' in pkg) {
 		return pkg.default;
 	}
 
-	return null;
+	return pkg;
 };
diff --git a/src/common/termios.ts b/src/common/termios.ts
index e38428f..4b94765 100644
--- a/src/common/termios.ts
+++ b/src/common/termios.ts
@@ -31,13 +31,13 @@ class Termios {
 	 * The data for the termios struct we are manipulating
 	 * @private
 	 */
-	readonly #termios: Uint8Array;
+	#termios: Uint8Array;
 
 	/**
 	 * The pointer to the termios struct
 	 * @private
 	 */
-	readonly #ptr: any;
+	#ptr;
 
 	constructor(ffi: IFFI) {
 		this.#ffi = ffi;
@@ -51,6 +51,13 @@ class Termios {
 		this.#ptr = ffi.getPointer(this.#termios);
 	}
 
+	cleanup() {
+		this.#ptr = null;
+		this.#cookedTermios = new Uint8Array(0);
+		this.#termios = new Uint8Array(0);
+		this.#ffi.close();
+	}
+
 	enableRawMode() {
 		if (this.#inRawMode) {
 			throw new Error('Can not enable raw mode when in raw mode');
diff --git a/src/common/utils.ts b/src/common/utils.ts
index db2fc22..c4d2503 100644
--- a/src/common/utils.ts
+++ b/src/common/utils.ts
@@ -1,11 +1,30 @@
-export function noop() {}
+// ----------------------------------------------------------------------------
+// Misc
+// ----------------------------------------------------------------------------
+
+export const noop = () => {};
 
 // ----------------------------------------------------------------------------
 // Strings
 // ----------------------------------------------------------------------------
 
+/**
+ * Get the codepoint of the first byte of a string. If the string
+ * is empty, this will return 256
+ *
+ * @param s - the string
+ */
+export function ord(s: string): number {
+	if (s.length > 0) {
+		return s.codePointAt(0)!;
+	}
+
+	return 256;
+}
+
 /**
  * Split a string by graphemes, not just bytes
+ *
  * @param s - the string to split into 'characters'
  */
 export function chars(s: string): string[] {
@@ -14,6 +33,7 @@ export function chars(s: string): string[] {
 
 /**
  * Get the 'character length' of a string, not its UTF16 byte count
+ *
  * @param s - the string to check
  */
 export function strlen(s: string): number {
@@ -21,19 +41,12 @@ export function strlen(s: string): number {
 }
 
 /**
- * Is the character part of ascii?
+ * Are all the characters in the string in ASCII range?
  *
- * @param char - a one character string to check
+ * @param char - string to check
  */
 export function is_ascii(char: string): boolean {
-	return chars(char).every((char) => {
-		const point = char.codePointAt(0);
-		if (point === undefined) {
-			return false;
-		}
-
-		return point < 0x80;
-	});
+	return chars(char).every((char) => ord(char) < 0x80);
 }
 
 /**
@@ -42,22 +55,19 @@ export function is_ascii(char: string): boolean {
  * @param char - a one character string to check
  */
 export function is_control(char: string): boolean {
-	const code = char.codePointAt(0);
-	if (code === undefined) {
-		return false;
-	}
-
+	const code = ord(char);
 	return is_ascii(char) && (code === 0x7f || code < 0x20);
 }
 
 /**
  * Get the key code for a ctrl chord
+ *
  * @param char - a one character string
  */
 export function ctrl_key(char: string): string {
 	// This is the normal use case, of course
 	if (is_ascii(char)) {
-		const point = char.codePointAt(0)!;
+		const point = ord(char);
 		return String.fromCodePoint(point & 0x1f);
 	}
 
diff --git a/src/common/utils_test.ts b/src/common/utils_test.ts
index b2ee1b2..a4900d8 100644
--- a/src/common/utils_test.ts
+++ b/src/common/utils_test.ts
@@ -1,59 +1,74 @@
-import { importDefaultForRuntime, ITestBase } from './mod.ts';
+import { getTestRunner } from './mod.ts';
 import {
 	chars,
 	ctrl_key,
 	is_ascii,
 	is_control,
+	noop,
+	ord,
 	strlen,
 	truncate,
 } from './utils.ts';
 
-const t: ITestBase = await importDefaultForRuntime('test_base');
+getTestRunner().then((t) => {
+	t.test('noop fn', () => {
+		t.assertExists(noop);
+		t.assertEquals(noop(), undefined);
+	});
 
-// ---------------------------------------------------------------------------------------------------------------------
-// Strings
-// ---------------------------------------------------------------------------------------------------------------------
+	// ---------------------------------------------------------------------------
+	// Strings
+	// ---------------------------------------------------------------------------
+	t.test('ord fn returns 256 on invalid string', () => {
+		t.assertEquals(ord(''), 256);
+	});
 
-t.test('chars fn properly splits strings into unicode characters', () => {
-	t.assertEquals(chars('😺😸😹'), ['😺', '😸', '😹']);
-});
-
-t.test('ctrl_key fn returns expected values', () => {
-	const ctrl_a = ctrl_key('a');
-	t.assertTrue(is_control(ctrl_a));
-	t.assertEquals(ctrl_a, String.fromCodePoint(0x01));
-
-	const invalid = ctrl_key('😺');
-	t.assertFalse(is_control(invalid));
-	t.assertEquals(invalid, '😺');
-});
-
-t.test('is_ascii properly discerns ascii chars', () => {
-	t.assertTrue(is_ascii('asjyverkjhsdf1928374'));
-	t.assertFalse(is_ascii('😺acalskjsdf'));
-});
-
-t.test('is_control fn works as expected', () => {
-	t.assertFalse(is_control('abc'));
-	t.assertTrue(is_control(String.fromCodePoint(0x01)));
-	t.assertFalse(is_control('😺'));
-});
-
-t.test('strlen fn returns expected length for multibyte characters', () => {
-	t.assertEquals(strlen('😺😸😹'), 3);
-	t.assertNotEquals('😺😸😹'.length, strlen('😺😸😹'));
-
-	// Skin tone modifier + base character
-	t.assertEquals(strlen('🤰🏼'), 2);
-	t.assertNotEquals('🤰🏼'.length, strlen('🤰🏼'));
-
-	// This has 4 sub-characters, and 3 zero-width-joiners
-	t.assertEquals(strlen('👨‍👩‍👧‍👦'), 7);
-	t.assertNotEquals('👨‍👩‍👧‍👦'.length, strlen('👨‍👩‍👧‍👦'));
-});
-
-t.test('truncate shortens strings', () => {
-	t.assertEquals(truncate('😺😸😹', 1), '😺');
-	t.assertEquals(truncate('😺😸😹', 5), '😺😸😹');
-	t.assertEquals(truncate('👨‍👩‍👧‍👦', 5), '👨‍👩‍👧');
+	t.test('chars fn properly splits strings into unicode characters', () => {
+		t.assertEquals(chars('😺😸😹'), ['😺', '😸', '😹']);
+	});
+
+	t.test('ctrl_key fn returns expected values', () => {
+		const ctrl_a = ctrl_key('a');
+		t.assertTrue(is_control(ctrl_a));
+		t.assertEquals(ctrl_a, String.fromCodePoint(0x01));
+
+		const invalid = ctrl_key('😺');
+		t.assertFalse(is_control(invalid));
+		t.assertEquals(invalid, '😺');
+	});
+
+	t.test('is_ascii properly discerns ascii chars', () => {
+		t.assertTrue(is_ascii('asjyverkjhsdf1928374'));
+		t.assertFalse(is_ascii('😺acalskjsdf'));
+		t.assertFalse(is_ascii('ab😺ac'));
+	});
+
+	t.test('is_control fn works as expected', () => {
+		t.assertFalse(is_control('abc'));
+		t.assertTrue(is_control(String.fromCodePoint(0x01)));
+		t.assertFalse(is_control('😺'));
+	});
+
+	t.test('strlen fn returns expected length for ascii strings', () => {
+		t.assertEquals(strlen('abc'), 'abc'.length);
+	});
+
+	t.test('strlen fn returns expected length for multibyte characters', () => {
+		t.assertEquals(strlen('😺😸😹'), 3);
+		t.assertNotEquals('😺😸😹'.length, strlen('😺😸😹'));
+
+		// Skin tone modifier + base character
+		t.assertEquals(strlen('🤰🏼'), 2);
+		t.assertNotEquals('🤰🏼'.length, strlen('🤰🏼'));
+
+		// This has 4 sub-characters, and 3 zero-width-joiners
+		t.assertEquals(strlen('👨‍👩‍👧‍👦'), 7);
+		t.assertNotEquals('👨‍👩‍👧‍👦'.length, strlen('👨‍👩‍👧‍👦'));
+	});
+
+	t.test('truncate shortens strings', () => {
+		t.assertEquals(truncate('😺😸😹', 1), '😺');
+		t.assertEquals(truncate('😺😸😹', 5), '😺😸😹');
+		t.assertEquals(truncate('👨‍👩‍👧‍👦', 5), '👨‍👩‍👧');
+	});
 });
diff --git a/src/deno/deps.ts b/src/deno/deps.ts
new file mode 100644
index 0000000..bca48ad
--- /dev/null
+++ b/src/deno/deps.ts
@@ -0,0 +1 @@
+export * as stdAssert from 'https://deno.land/std@0.205.0/assert/mod.ts';
diff --git a/src/deno/ffi.ts b/src/deno/ffi.ts
index f2c03ff..01c8786 100644
--- a/src/deno/ffi.ts
+++ b/src/deno/ffi.ts
@@ -39,6 +39,7 @@ const DenoFFI: IFFI = {
 	tcsetattr,
 	cfmakeraw,
 	getPointer: Deno.UnsafePointer.of,
+	close: cStdLib.close,
 };
 
 export default DenoFFI;
diff --git a/src/deno/file_io.ts b/src/deno/file_io.ts
index 69d38ef..13a8727 100644
--- a/src/deno/file_io.ts
+++ b/src/deno/file_io.ts
@@ -1,6 +1,6 @@
-import { IFIO } from '../common/runtime.ts';
+import { IFileIO } from '../common/runtime.ts';
 
-const DenoFileIO: IFIO = {
+const DenoFileIO: IFileIO = {
 	openFile: async function (path: string): Promise<string> {
 		const decoder = new TextDecoder('utf-8');
 		const data = await Deno.readFile(path);
diff --git a/src/deno/test_base.ts b/src/deno/test_base.ts
index 852e809..d6070fb 100644
--- a/src/deno/test_base.ts
+++ b/src/deno/test_base.ts
@@ -1,13 +1,13 @@
 import { ITestBase } from '../common/mod.ts';
-
-import {
+import { stdAssert } from './deps.ts';
+const {
 	assertEquals,
 	assertExists,
 	assertInstanceOf,
 	AssertionError,
 	assertNotEquals,
 	assertStrictEquals,
-} from 'https://deno.land/std/assert/mod.ts';
+} = stdAssert;
 
 class TestBase implements ITestBase {
 	test(name: string, fn: () => void): void {