Add tests for k6 init command

cmd/init.go

@@ -1,6 +1,7 @@
 package cmd
 
 import (
+	"errors"
 	"fmt"
 	"path"
 	"text/template"
@@ -13,7 +14,10 @@ import (
 
 const defaultNewScriptName = "script.js"
 
-var defaultNewScriptTemplate = template.Must(template.New("init").Parse(`import http from 'k6/http';
+//nolint:gochecknoglobals
+var (
+	errFileExists            = errors.New("file already exists")
+	defaultNewScriptTemplate = template.Must(template.New("init").Parse(`import http from 'k6/http';
 import { sleep } from 'k6';
 
 export const options = {
@@ -69,6 +73,7 @@ export default function() {
   sleep(1);
 }
 `))
+)
 
 type initScriptTemplateArgs struct {
 	ScriptName string
@@ -88,7 +93,7 @@ func (c *initCmd) flagSet() *pflag.FlagSet {
 	return flags
 }
 
-func (c *initCmd) run(cmd *cobra.Command, args []string) error {
+func (c *initCmd) run(cmd *cobra.Command, args []string) error { //nolint:revive
 	target := defaultNewScriptName
 	if len(args) > 0 {
 		target = args[0]
@@ -101,14 +106,14 @@ func (c *initCmd) run(cmd *cobra.Command, args []string) error {
 
 	if fileExists && !c.overwriteFiles {
 		c.gs.Logger.Errorf("%s already exists", target)
-		return err
+		return errFileExists
 	}
 
 	fd, err := c.gs.FS.Create(target)
 	if err != nil {
 		return err
 	}
-	defer fd.Close()
+	defer fd.Close() //nolint:errcheck
 
 	if err := defaultNewScriptTemplate.Execute(fd, initScriptTemplateArgs{
 		ScriptName: path.Base(target),

cmd/init_test.go

@@ -0,0 +1,97 @@
+package cmd
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"go.k6.io/k6/cmd/tests"
+	"go.k6.io/k6/lib/fsext"
+)
+
+func TestInitScript(t *testing.T) {
+	t.Parallel()
+
+	testCases := []struct {
+		name              string
+		scriptNameArg     string
+		expectedCloudName string
+		expectedFilePath  string
+	}{
+		{
+			name:              "default script name",
+			expectedCloudName: "script.js",
+			expectedFilePath:  defaultNewScriptName,
+		},
+		{
+			name:              "user-specified script name",
+			scriptNameArg:     "mytest.js",
+			expectedCloudName: "mytest.js",
+			expectedFilePath:  "mytest.js",
+		},
+		{
+			name:              "script outside of current working directory",
+			scriptNameArg:     "../mytest.js",
+			expectedCloudName: "mytest.js",
+			expectedFilePath:  "../mytest.js",
+		},
+	}
+
+	for _, testCase := range testCases {
+		testCase := testCase
+		t.Run(testCase.name, func(t *testing.T) {
+			t.Parallel()
+
+			ts := tests.NewGlobalTestState(t)
+			ts.CmdArgs = []string{"k6", "init"}
+			if testCase.scriptNameArg != "" {
+				ts.CmdArgs = append(ts.CmdArgs, testCase.scriptNameArg)
+			}
+
+			newRootCommand(ts.GlobalState).execute()
+
+			data, err := fsext.ReadFile(ts.FS, testCase.expectedFilePath)
+			require.NoError(t, err)
+
+			jsData := string(data)
+			assert.Contains(t, jsData, "export const options = {")
+			assert.Contains(t, jsData, fmt.Sprintf(`name: "%s"`, testCase.expectedCloudName))
+			assert.Contains(t, jsData, "export default function() {")
+		})
+	}
+}
+
+func TestInitScript_FileExists_NoOverwrite(t *testing.T) {
+	t.Parallel()
+
+	ts := tests.NewGlobalTestState(t)
+	require.NoError(t, fsext.WriteFile(ts.FS, defaultNewScriptName, []byte("untouched"), 0o644))
+
+	ts.CmdArgs = []string{"k6", "init"}
+	ts.ExpectedExitCode = -1
+
+	newRootCommand(ts.GlobalState).execute()
+
+	data, err := fsext.ReadFile(ts.FS, defaultNewScriptName)
+	require.NoError(t, err)
+
+	assert.Contains(t, string(data), "untouched")
+}
+
+func TestInitScript_FileExists_Overwrite(t *testing.T) {
+	t.Parallel()
+
+	ts := tests.NewGlobalTestState(t)
+	require.NoError(t, fsext.WriteFile(ts.FS, defaultNewScriptName, []byte("untouched"), 0o644))
+
+	ts.CmdArgs = []string{"k6", "init", "-f"}
+
+	newRootCommand(ts.GlobalState).execute()
+
+	data, err := fsext.ReadFile(ts.FS, defaultNewScriptName)
+	require.NoError(t, err)
+
+	assert.Contains(t, string(data), "export const options = {")
+	assert.Contains(t, string(data), "export default function() {")
+}