diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e3edb07..f47bfd2 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -25,7 +25,7 @@ jobs:
     # when https://github.com/nodejs/node/pull/54429 is landed and node 18 EOL
     - run: |
         COV_PERCENT_MIN=90
-        COV_PERCENT=$(npm test | grep 'all' | cut -d'|' -f3) # all files branch cov
+        COV_PERCENT=$(npm test | grep 'all files' | cut -d'|' -f3) # all files branch cov
         echo "branch coverage $COV_PERCENT should be greater then $COV_PERCENT_MIN"
         node -e "process.exit($COV_PERCENT > $COV_PERCENT_MIN ? 0 : 1)"
   semgrep:
diff --git a/tests/UserInput.js b/tests/UserInput.js
new file mode 100644
index 0000000..48469a2
--- /dev/null
+++ b/tests/UserInput.js
@@ -0,0 +1,128 @@
+const {describe, it, mock} = require('node:test')
+const assert = require('assert')
+const UserInput = require('../lib/UserInput')
+
+describe('UserInput', () => {
+	const PLEASE_ANSWER_MESSAGE = "Please answer 'y' or 'n'"
+	const TEST_MESSAGE = 'test message'
+
+	it('ask() returns FUZZ_USER_REPLY when FUZZ is enabled', async () => {
+		const originalFuzz = global.FUZZ
+		const originalReply = global.FUZZ_USER_REPLY
+
+		try {
+			global.FUZZ = true
+			global.FUZZ_USER_REPLY = '  YeS  '
+
+			const ui = new UserInput({question: 'Test question?'})
+			const result = await ui.ask()
+
+			assert.strictEqual(result, '  YeS  ')
+		} finally {
+			global.FUZZ = originalFuzz
+			global.FUZZ_USER_REPLY = originalReply
+		}
+	})
+
+	it('confirm() returns true for positive answers', async () => {
+		const positiveAnswers = ['y', 'yes', '']
+
+		for (const answer of positiveAnswers) {
+			const ui = new UserInput({question: 'Confirm?'})
+			ui.ask = async () => answer
+
+			const result = await ui.confirm()
+			assert.strictEqual(result, true, `Expected true for answer: "${answer}"`)
+		}
+	})
+
+	it('confirm() returns false for negative answers', async () => {
+		const negativeAnswers = ['n', 'no']
+
+		for (const answer of negativeAnswers) {
+			const ui = new UserInput({question: 'Confirm?'})
+			ui.ask = async () => answer
+
+			const result = await ui.confirm()
+			assert.strictEqual(result, false, `Expected false for answer: "${answer}"`)
+		}
+	})
+
+	it('confirm() retries on invalid input and succeeds on valid input', async () => {
+		const logCalls = []
+		mock.method(console, 'log', function(msg) {
+			logCalls.push(msg)
+		})
+
+		const replies = ['maybe', 'y']
+		const ui = new UserInput({question: 'Confirm?'})
+		ui.ask = async () => replies.shift()
+
+		const result = await ui.confirm()
+
+		assert.strictEqual(result, true)
+		assert.strictEqual(logCalls.length, 1)
+		assert.ok(logCalls[0].includes(PLEASE_ANSWER_MESSAGE))
+	})
+
+	it('confirm() gives up after 3 invalid attempts', async () => {
+		const logCalls = []
+		mock.method(console, 'log', function(msg) {
+			logCalls.push(msg)
+		})
+
+		const replies = ['foo', 'bar', 'baz']
+		const ui = new UserInput({question: 'Confirm?'})
+		ui.ask = async () => replies.shift()
+
+		const result = await ui.confirm()
+
+		assert.strictEqual(result, false)
+		assert.strictEqual(logCalls.length, 3)
+		logCalls.forEach(call => {
+			assert.ok(call.includes(PLEASE_ANSWER_MESSAGE))
+		})
+	})
+
+	it('log() returns empty string and does not log when FUZZ is enabled', async () => {
+		const originalFuzz = global.FUZZ
+
+		try {
+			global.FUZZ = true
+
+			const logCalls = []
+			mock.method(console, 'log', function(msg) {
+				logCalls.push(msg)
+			})
+
+			const ui = new UserInput({question: 'Test?'})
+			const result = ui.log(TEST_MESSAGE)
+
+			assert.strictEqual(result, '')
+			assert.strictEqual(logCalls.length, 0)
+		} finally {
+			global.FUZZ = originalFuzz
+		}
+	})
+
+	it('log() calls console.log when FUZZ is not enabled', async () => {
+		const originalFuzz = global.FUZZ
+
+		try {
+			global.FUZZ = false
+
+			const logCalls = []
+			mock.method(console, 'log', function(msg) {
+				logCalls.push(msg)
+			})
+
+			const ui = new UserInput({question: 'Test?'})
+			ui.log(TEST_MESSAGE)
+
+			assert.strictEqual(logCalls.length, 1)
+			assert.strictEqual(logCalls[0], TEST_MESSAGE)
+		} finally {
+			global.FUZZ = originalFuzz
+		}
+	})
+})