Trim spaces and add unit tests for cli.confirm function (#5909)

* Add unit test for cli.confirm function

* Trim spaces

* Add license header

* Adding CHANGELOG entry

* Reorder imports

* Refactoring

changelog/fragments/1730418510-confirm-test.yaml

@@ -0,0 +1,32 @@
+# Kind can be one of:
+# - breaking-change: a change to previously-documented behavior
+# - deprecation: functionality that is being removed in a later release
+# - bug-fix: fixes a problem in a previous version
+# - enhancement: extends functionality but does not break or fix existing behavior
+# - feature: new functionality
+# - known-issue: problems that we are aware of in a given version
+# - security: impacts on the security of a product or a user’s deployment.
+# - upgrade: important information for someone upgrading from a prior version
+# - other: does not fit into any of the other categories
+kind: bug-fix
+
+# Change summary; a 80ish characters long description of the change.
+summary: Allows users to enter spaces around yes/no inputs in CLI confirmation prompts.
+
+# Long description; in case the summary is not enough to describe the change
+# this field accommodate a description without length limits.
+# NOTE: This field will be rendered only for breaking-change and known-issue kinds at the moment.
+#description:
+
+# Affected component; usually one of "elastic-agent", "fleet-server", "filebeat", "metricbeat", "auditbeat", "all", etc.
+component: elastic-agent
+
+# PR URL; optional; the PR number that added the changeset.
+# If not present is automatically filled by the tooling finding the PR where this changelog fragment has been added.
+# NOTE: the tooling supports backports, so it's able to fill the original PR number instead of the backport PR number.
+# Please provide it if you are adding a fragment for a different PR.
+pr: https://github.com/elastic/elastic-agent/pull/5909
+
+# Issue URL; optional; the GitHub issue related to this changeset (either closes or is part of).
+# If not present is automatically filled by the tooling with the issue linked to the PR number.
+#issue: https://github.com/owner/repo/1234

internal/pkg/cli/confirm.go

@@ -34,7 +34,7 @@ func confirm(r io.Reader, out io.Writer, prompt string, def bool) (bool, error)
 		if !reader.Scan() {
 			break
 		}
-		switch strings.ToLower(reader.Text()) {
+		switch strings.ToLower(strings.TrimSpace(reader.Text())) {
 		case "":
 			return def, nil
 		case "y", "yes", "yeah":

internal/pkg/cli/confirm_test.go

@@ -0,0 +1,75 @@
+// Copyright Elasticsearch B.V. and/or licensed to Elasticsearch B.V. under one
+// or more contributor license agreements. Licensed under the Elastic License 2.0;
+// you may not use this file except in compliance with the Elastic License 2.0.
+
+package cli
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestConfirm(t *testing.T) {
+	cases := map[string]struct {
+		expectedResult bool
+		expectedErr    string
+	}{
+		"y":    {true, ""},
+		"y ":   {true, ""},
+		" y":   {true, ""},
+		"y\t":  {true, ""},
+		"\ty":  {true, ""},
+		"yes":  {true, ""},
+		"yeah": {true, ""},
+		"Y":    {true, ""},
+		"YES":  {true, ""},
+		"YEAH": {true, ""},
+		"Yes":  {true, ""},
+		"Yeah": {true, ""},
+		"Yup":  {false, "error reading user input"},
+		"n":    {false, ""},
+		"n ":   {false, ""},
+		" n":   {false, ""},
+		"n\t":  {false, ""},
+		"\tn":  {false, ""},
+		"no":   {false, ""},
+		"N":    {false, ""},
+		"NO":   {false, ""},
+		"No":   {false, ""},
+		"nope": {false, "error reading user input"},
+	}
+
+	testFn := func(t *testing.T, input string, def, expectedResult bool, expectedErr string) {
+		inputReader := strings.NewReader(input)
+		var outWriter strings.Builder
+		result, err := confirm(inputReader, &outWriter, "prompt", def)
+
+		prompt := "prompt "
+		if def {
+			prompt += "[Y/n]:"
+		} else {
+			prompt += "[y/N]:"
+		}
+
+		require.Equal(t, expectedResult, result)
+		if expectedErr == "" {
+			require.NoError(t, err)
+			require.Equal(t, prompt, outWriter.String())
+		} else {
+			expectedOut := prompt + "Please write 'y' or 'n'\n" + prompt
+			require.Equal(t, expectedErr, err.Error())
+			require.Equal(t, expectedOut, outWriter.String())
+		}
+	}
+
+	for input, test := range cases {
+		t.Run(input+"-default-to-yes", func(t *testing.T) {
+			testFn(t, input, true, test.expectedResult, test.expectedErr)
+		})
+		t.Run(input+"-default-to-no", func(t *testing.T) {
+			testFn(t, input, false, test.expectedResult, test.expectedErr)
+		})
+	}
+}