diff --git a/.eslintrc b/.eslintrc
new file mode 100644
index 0000000..864e43e
--- /dev/null
+++ b/.eslintrc
@@ -0,0 +1,32 @@
+{
+	"root": true,
+
+	"extends": "@ljharb",
+
+	"rules": {
+		"func-style": ["error", "declaration"],
+		"max-lines-per-function": "off",
+		"max-statements-per-line": ["error", { "max": 2 }],
+		"no-plusplus": "warn",
+		"sort-keys": "off",
+	},
+
+	"overrides": [
+		{
+			"files": "bin/**",
+			"env": {
+				"node": true,
+			},
+			"rules": {
+				"no-process-exit": "off",
+			}
+		},
+		{
+			"files": "example/**",
+			"rules": {
+				"no-magic-numbers": "off",
+				"no-plusplus": "off",
+			},
+		},
+	],
+}
diff --git a/bin/cmd.js b/bin/cmd.js
index 489a7c2..2c12800 100755
--- a/bin/cmd.js
+++ b/bin/cmd.js
@@ -1,4 +1,7 @@
 #!/usr/bin/env node
+
+'use strict';
+
 var faucet = require('../');
 var minimist = require('minimist');
 var defined = require('defined');
@@ -9,52 +12,50 @@ var spawn = require('child_process').spawn;
 var fs = require('fs');
 var path = require('path');
 
+function jsFile(x) { return (/\.js$/i).test(x); }
+
 var argv = minimist(process.argv.slice(2));
 var tap = faucet({
-    width: defined(argv.w, argv.width, process.stdout.isTTY
-        ? process.stdout.columns - 5
-        : 0
-    )
+	width: defined(argv.w, argv.width, process.stdout.isTTY
+		? process.stdout.columns - 5
+		: 0)
 });
 process.on('exit', function (code) {
-    if (code === 0 && tap.exitCode !== 0) {
-        process.exit(tap.exitCode);
-    }
+	if (code === 0 && tap.exitCode !== 0) {
+		process.exit(tap.exitCode);
+	}
 });
 process.stdout.on('error', function () {});
 
 if (!process.stdin.isTTY || argv._[0] === '-') {
-    process.stdin.pipe(tap).pipe(process.stdout);
-    return;
+	process.stdin.pipe(tap).pipe(process.stdout);
+	return;
 }
 
 var files = argv._.reduce(function (acc, file) {
-    if (fs.statSync(file).isDirectory()) {
-        return acc.concat(fs.readdirSync(file).map(function (x) {
-            return path.join(file, x);
-        }).filter(jsFile));
-    }
-    else return acc.concat(file);
+	if (fs.statSync(file).isDirectory()) {
+		return acc.concat(fs.readdirSync(file).map(function (x) {
+			return path.join(file, x);
+		}).filter(jsFile));
+	}
+	return acc.concat(file);
 }, []);
 
 if (files.length === 0 && fs.existsSync('test')) {
-    files.push.apply(files, fs.readdirSync('test').map(function (x) {
-        return path.join('test', x);
-    }).filter(jsFile));
+	files.push.apply(files, fs.readdirSync('test').map(function (x) {
+		return path.join('test', x);
+	}).filter(jsFile));
 }
 if (files.length === 0 && fs.existsSync('tests')) {
-    files.push.apply(files, fs.readdirSync('tests').map(function (x) {
-        return path.join('tests', x);
-    }).filter(jsFile));
+	files.push.apply(files, fs.readdirSync('tests').map(function (x) {
+		return path.join('tests', x);
+	}).filter(jsFile));
 }
 
 if (files.length === 0) {
-    console.error('usage: `faucet [FILES]` or `| faucet`\n');
-    console.error(
-        'No test files or stdin provided and no files in test/ or tests/'
-        + ' directories found.'
-    );
-    return process.exit(1);
+	console.error('usage: `faucet [FILES]` or `| faucet`\n');
+	console.error('No test files or stdin provided and no files in test/ or tests/ directories found.');
+	process.exit(1);
 }
 
 var tape = spawn(tapeCmd, files);
@@ -62,12 +63,10 @@ tape.stderr.pipe(process.stderr);
 tape.stdout.pipe(tap).pipe(process.stdout);
 
 var tapeCode;
-tape.on('exit', function (code) { tapeCode = code });
+tape.on('exit', function (code) { tapeCode = code; });
 process.on('exit', function (code) {
-    if (code === 0 && tapeCode !== 0) {
-        console.error('# non-zero exit from the `tape` command');
-        process.exit(tapeCode);
-    }
+	if (code === 0 && tapeCode !== 0) {
+		console.error('# non-zero exit from the `tape` command');
+		process.exit(tapeCode);
+	}
 });
-
-function jsFile (x) { return /\.js$/i.test(x) }
diff --git a/example/tape.js b/example/tape.js
index 5ab9c11..4df3914 100644
--- a/example/tape.js
+++ b/example/tape.js
@@ -1,13 +1,17 @@
+'use strict';
+
 var test = require('tape');
 
 test('beep boop', function (t) {
-    t.plan(2);
-    
-    t.equal(1 + 1, 2);
-    setTimeout(function () {
-        t.deepEqual(
-            'ABC'.toLowerCase().split(''),
-            ['a','b','c']
-        );
-    });
+	t.plan(2);
+
+	t.equal(1 + 1, 2);
+	setTimeout(function () {
+		t.deepEqual(
+			'ABC'.toLowerCase().split(''),
+			[
+				'a', 'b', 'c'
+			]
+		);
+	});
 });
diff --git a/example/test.js b/example/test.js
index 947a4cf..6cf55f9 100644
--- a/example/test.js
+++ b/example/test.js
@@ -1,27 +1,33 @@
+'use strict';
+
 var test = require('tape');
-function getMessage () {
-    var msgs = [ 'yes', 'equals', 'matches', 'yep', 'pretty much', 'woo' ];
-    return msgs[Math.floor(Math.random() * msgs.length)];
+
+function getMessage() {
+	var msgs = [
+		'yes', 'equals', 'matches', 'yep', 'pretty much', 'woo'
+	];
+	return msgs[Math.floor(Math.random() * msgs.length)];
 }
 
 test('beep affirmative', function (t) {
-    t.plan(24);
-    var i = 0, n = 0;
-    var iv = setInterval(function () {
-        t.equal(i++, n++, getMessage());
-        if (i === 24) clearInterval(iv);
-    }, 50);
+	t.plan(24);
+	var i = 0,
+		n = 0;
+	var iv = setInterval(function () {
+		t.equal(i++, n++, getMessage());
+		if (i === 24) { clearInterval(iv); }
+	}, 50);
 });
 
 test('boop exterminate', function (t) {
-    t.plan(20);
-    var i = 0, n = 0;
-    var iv = setInterval(function () {
-        if ((i + 2) % 8 === 0) {
-            t.equal(i, n + 6, getMessage())
-        }
-        else t.equal(i, n, getMessage());
-        i++; n++;
-        if (i === 20) clearInterval(iv);
-    }, 100);
+	t.plan(20);
+	var i = 0,
+		n = 0;
+	var iv = setInterval(function () {
+		if ((i + 2) % 8 === 0) {
+			t.equal(i, n + 6, getMessage());
+		} else { t.equal(i, n, getMessage()); }
+		i++; n++;
+		if (i === 20) { clearInterval(iv); }
+	}, 100);
 });
diff --git a/index.js b/index.js
index 3871866..3d82113 100644
--- a/index.js
+++ b/index.js
@@ -1,123 +1,115 @@
+'use strict';
+
 var through2 = require('through2');
 var duplexer = require('duplexer');
 var parser = require('tap-parser');
 var sprintf = require('sprintf-js').sprintf;
 
 module.exports = function (opts) {
-    if (!opts) opts = {};
-    var tap = parser();
-    var out = through2();
-    var test, lastAssert;
-    
-    tap.on('comment', function (comment) {
-        if (comment === 'fail 0') return; // a mocha thing
-        
-        if (test && test.ok && test.assertions.length === 0
-        && /^(tests|pass)\s+\d+$/.test(test.name)) {
-            out.push('\r' + trim(test.name));
-        }
-        else if (test && test.ok) {
-            var s = updateName(test.offset + 1, '✓ ' + test.name, 32);
-            out.push('\r' + s);
-        }
-        
-        test = {
-            name: comment,
-            assertions: [],
-            offset: 0,
-            ok: true
-        };
-        out.push('\r' + trim('# ' + comment) + '\x1b[K\n');
-    });
-    
-    tap.on('assert', function (res) {
-        var ok = res.ok ? 'ok' : 'not ok';
-        var c = res.ok ? 32 : 31;
-        if (!test) {
-            // mocha produces TAP results this way, whatever
-            var s = trim(res.name.trim());
-            out.push(sprintf(
-                '\x1b[1m\x1b[' + c + 'm%s\x1b[0m\n',
-                trim((res.ok ? '✓' : '⨯') + ' ' +  s)
-            ));
-            return;
-        }
-        
-        var fmt = '\r  %s \x1b[1m\x1b[' + c + 'm%d\x1b[0m %s\x1b[K';
-        var str = sprintf(fmt, ok, res.number, res.name);
-        
-        if (!res.ok) {
-            var y = (++ test.offset) + 1;
-            str += '\n';
-            if (test.ok) {
-                str += updateName(y, '⨯ ' + test.name, 31)
-            }
-            test.ok = false;
-        }
-        out.push(str);
-        test.assertions.push(res);
-    });
-    
-    tap.on('extra', function (extra) {
-        if (!test || test.assertions.length === 0) return;
-        var last = test.assertions[test.assertions.length-1];
-        if (!last.ok) {
-            out.push(extra.split('\n').map(function (line) {
-                return '  ' + line;
-            }).join('\n') + '\n');
-        }
-    });
-    
-    tap.on('results', function (res) {
-        if (test && /^fail\s+\d+$/.test(test.name)) {
-            out.push(updateName(test.offset + 1, '⨯ ' + test.name, 31));
-        }
-        else if (test && test.ok) {
-            out.push(updateName(test.offset + 1, '✓ ' + test.name, 32));
-        }
-        
-        res.errors.forEach(function (err, ix) {
-            out.push(sprintf(
-                'not ok \x1b[1m\x1b[31m%d\x1b[0m %s\n',
-                ix + 1 + res.asserts.length, err.message
-            ));
-        });
-        
-        if (!res.ok && !/^fail\s+\d+$/.test(test && test.name)) {
-            out.push(sprintf(
-                '\r\x1b[1m\x1b[31m⨯ fail  %s\x1b[0m\x1b[K\n',
-                (res.errors.length + res.fail.length) || ''
-            ));
-        }
-        
-        out.push(null);
-        
-        dup.emit('results', res);
-        if (!res.ok) dup.emit('fail');
-        dup.exitCode = res.ok ? 0 : 1;
-    });
-    
-    var dup = duplexer(tap, out);
-    return dup;
-    
-    function showTest (test) {
-        out.push('\r');
-    }
-    
-    function trim (s) {
-        if (opts.width && s.length > opts.width - 2) {
-            s = s.slice(0, opts.width - 5) + '...';
-        }
-        return s;
-    }
-    
-    function updateName (y, str, c) {
-        return '\x1b[' + y + 'A'
-            + '\x1b[1G'
-            + '\x1b[1m\x1b[' + c + 'm'
-            + trim(str)
-            + '\x1b[0m'
-            + '\x1b[' + y + 'B\x1b[1G'
-        ;
-    }
+	var tap = parser();
+	var out = through2();
+
+	function trim(s) {
+		if (opts && opts.width && s.length > opts.width - 2) {
+			return s.slice(0, opts.width - 5) + '...';
+		}
+		return s;
+	}
+
+	function updateName(y, str, c) {
+		return '\x1b[' + y + 'A\x1b[1G\x1b[1m\x1b[' + c + 'm' + trim(str) + '\x1b[0m\x1b[' + y + 'B\x1b[1G';
+	}
+
+	var test;
+
+	tap.on('comment', function (comment) {
+		if (comment === 'fail 0') { return; } // a mocha thing
+
+		if (test && test.ok && test.assertions.length === 0
+        && (/^(tests|pass)\s+\d+$/).test(test.name)) {
+			out.push('\r' + trim(test.name));
+		} else if (test && test.ok) {
+			var s = updateName(test.offset + 1, '✓ ' + test.name, 32);
+			out.push('\r' + s);
+		}
+
+		test = {
+			name: comment,
+			assertions: [],
+			offset: 0,
+			ok: true
+		};
+		out.push('\r' + trim('# ' + comment) + '\x1b[K\n');
+	});
+
+	tap.on('assert', function (res) {
+		var ok = res.ok ? 'ok' : 'not ok';
+		var c = res.ok ? 32 : 31;
+		if (!test) {
+			// mocha produces TAP results this way, whatever
+			var s = trim(res.name.trim());
+			out.push(sprintf(
+				'\x1b[1m\x1b[' + c + 'm%s\x1b[0m\n',
+				trim((res.ok ? '✓' : '⨯') + ' ' + s)
+			));
+			return;
+		}
+
+		var fmt = '\r  %s \x1b[1m\x1b[' + c + 'm%d\x1b[0m %s\x1b[K';
+		var str = sprintf(fmt, ok, res.number, res.name);
+
+		if (!res.ok) {
+			var y = ++test.offset + 1;
+			str += '\n';
+			if (test.ok) {
+				str += updateName(y, '⨯ ' + test.name, 31);
+			}
+			test.ok = false;
+		}
+		out.push(str);
+		test.assertions.push(res);
+	});
+
+	tap.on('extra', function (extra) {
+		if (!test || test.assertions.length === 0) { return; }
+		var last = test.assertions[test.assertions.length - 1];
+		if (!last.ok) {
+			out.push(extra.split('\n').map(function (line) {
+				return '  ' + line;
+			}).join('\n') + '\n');
+		}
+	});
+
+	var dup = duplexer(tap, out);
+
+	tap.on('results', function (res) {
+		if (test && (/^fail\s+\d+$/).test(test.name)) {
+			out.push(updateName(test.offset + 1, '⨯ ' + test.name, 31));
+		} else if (test && test.ok) {
+			out.push(updateName(test.offset + 1, '✓ ' + test.name, 32));
+		}
+
+		res.errors.forEach(function (err, ix) {
+			out.push(sprintf(
+				'not ok \x1b[1m\x1b[31m%d\x1b[0m %s\n',
+				ix + 1 + res.asserts.length,
+				err.message
+			));
+		});
+
+		if (!res.ok && !(/^fail\s+\d+$/).test(test && test.name)) {
+			out.push(sprintf(
+				'\r\x1b[1m\x1b[31m⨯ fail  %s\x1b[0m\x1b[K\n',
+				(res.errors.length + res.fail.length) || ''
+			));
+		}
+
+		out.push(null);
+
+		dup.emit('results', res);
+		if (!res.ok) { dup.emit('fail'); }
+		dup.exitCode = res.ok ? 0 : 1;
+	});
+
+	return dup;
 };
diff --git a/package.json b/package.json
index ec4d6a6..276309e 100644
--- a/package.json
+++ b/package.json
@@ -6,6 +6,10 @@
   "bin": {
     "faucet": "bin/cmd.js"
   },
+  "scripts": {
+	"lint": "eslint --ext=js,mjs .",
+	"pretest": "npm run lint"
+  },
   "dependencies": {
     "defined": "^0.0.0",
     "duplexer": "^0.1.2",
@@ -34,5 +38,9 @@
     "email": "mail@substack.net",
     "url": "http://substack.net"
   },
-  "license": "MIT"
+  "license": "MIT",
+  "devDependencies": {
+    "@ljharb/eslint-config": "^21.0.0",
+    "eslint": "=8.8.0"
+  }
 }