Merge pull request #3394 from grafana/add_k6_init

Add k6 new subcommand

.gitignore

@@ -10,6 +10,8 @@
 *.syso
 .idea
 *.DS_Store
+# Excluding as it is the file generated by the k6 init command
+script.js
 
 /versioninfo.json
 

cmd/new.go

@@ -0,0 +1,169 @@
+package cmd
+
+import (
+	"fmt"
+	"path"
+	"text/template"
+
+	"github.com/fatih/color"
+	"github.com/spf13/cobra"
+	"github.com/spf13/pflag"
+	"go.k6.io/k6/cmd/state"
+	"go.k6.io/k6/lib/fsext"
+)
+
+const defaultNewScriptName = "script.js"
+
+//nolint:gochecknoglobals
+var defaultNewScriptTemplate = template.Must(template.New("new").Parse(`import http from 'k6/http';
+import { sleep } from 'k6';
+
+export const options = {
+  // A number specifying the number of VUs to run concurrently.
+  vus: 10,
+  // A string specifying the total duration of the test run.
+  duration: '30s',
+
+  // The following section contains configuration options for execution of this
+  // test script in Grafana Cloud.
+  //
+  // See https://grafana.com/docs/grafana-cloud/k6/get-started/run-cloud-tests-from-the-cli/
+  // to learn about authoring and running k6 test scripts in Grafana k6 Cloud.
+  //
+  // ext: {
+  //   loadimpact: {
+  //     // The ID of the project to which the test is assigned in the k6 Cloud UI.
+  //     // By default tests are executed in default project.
+  //     projectID: "",
+  //     // The name of the test in the k6 Cloud UI.
+  //     // Test runs with the same name will be grouped.
+  //     name: "{{ .ScriptName }}"
+  //   }
+  // },
+
+  // Uncomment this section to enable the use of Browser API in your tests.
+  //
+  // See https://grafana.com/docs/k6/latest/using-k6-browser/running-browser-tests/ to learn more
+  // about using Browser API in your test scripts.
+  //
+  // scenarios: {
+  //   // The scenario name appears in the result summary, tags, and so on.
+  //   // You can give the scenario any name, as long as each name in the script is unique.
+  //   ui: {
+  //     // Executor is a mandatory parameter for browser-based tests.
+  //     // Shared iterations in this case tells k6 to reuse VUs to execute iterations.
+  //     //
+  //     // See https://grafana.com/docs/k6/latest/using-k6/scenarios/executors/ for other executor types.
+  //     executor: 'shared-iterations',
+  //     options: {
+  //       browser: {
+  //         // This is a mandatory parameter that instructs k6 to launch and
+  //         // connect to a chromium-based browser, and use it to run UI-based
+  //         // tests.
+  //         type: 'chromium',
+  //       },
+  //     },
+  //   },
+  // }
+};
+
+// The function that defines VU logic.
+//
+// See https://grafana.com/docs/k6/latest/examples/get-started-with-k6/ to learn more
+// about authoring k6 scripts.
+//
+export default function() {
+  http.get('https://test.k6.io');
+  sleep(1);
+}
+`))
+
+type initScriptTemplateArgs struct {
+	ScriptName string
+}
+
+// newScriptCmd represents the `k6 new` command
+type newScriptCmd struct {
+	gs             *state.GlobalState
+	overwriteFiles bool
+}
+
+func (c *newScriptCmd) flagSet() *pflag.FlagSet {
+	flags := pflag.NewFlagSet("", pflag.ContinueOnError)
+	flags.SortFlags = false
+	flags.BoolVarP(&c.overwriteFiles, "force", "f", false, "Overwrite existing files")
+
+	return flags
+}
+
+func (c *newScriptCmd) run(cmd *cobra.Command, args []string) error { //nolint:revive
+	target := defaultNewScriptName
+	if len(args) > 0 {
+		target = args[0]
+	}
+
+	fileExists, err := fsext.Exists(c.gs.FS, target)
+	if err != nil {
+		return err
+	}
+
+	if fileExists && !c.overwriteFiles {
+		return fmt.Errorf("%s already exists, please use the `--force` flag if you want overwrite it", target)
+	}
+
+	fd, err := c.gs.FS.Create(target)
+	if err != nil {
+		return err
+	}
+	defer func() {
+		_ = fd.Close() // we may think to check the error and log
+	}()
+
+	if err := defaultNewScriptTemplate.Execute(fd, initScriptTemplateArgs{
+		ScriptName: path.Base(target),
+	}); err != nil {
+		return err
+	}
+
+	valueColor := getColor(c.gs.Flags.NoColor || !c.gs.Stdout.IsTTY, color.Bold)
+	printToStdout(c.gs, fmt.Sprintf(
+		"Initialized a new k6 test script in %s. You can now execute it by running `%s run %s`.\n",
+		valueColor.Sprint(target),
+		c.gs.BinaryName,
+		target,
+	))
+
+	return nil
+}
+
+func getCmdNewScript(gs *state.GlobalState) *cobra.Command {
+	c := &newScriptCmd{gs: gs}
+
+	exampleText := getExampleText(gs, `
+  # Create a minimal k6 script in the current directory. By default, k6 creates script.js.
+  {{.}} new
+
+  # Create a minimal k6 script in the current directory and store it in test.js
+  {{.}} new test.js
+
+  # Overwrite existing test.js with a minimal k6 script
+  {{.}} new -f test.js`[1:])
+
+	initCmd := &cobra.Command{
+		Use:   "new",
+		Short: "Create and initialize a new k6 script",
+		Long: `Create and initialize a new k6 script.
+
+This command will create a minimal k6 script in the current directory and
+store it in the file specified by the first argument. If no argument is
+provided, the script will be stored in script.js.
+
+This command will not overwrite existing files.`,
+		Example: exampleText,
+		Args:    cobra.MaximumNArgs(1),
+		RunE:    c.run,
+	}
+	initCmd.Flags().AddFlagSet(c.flagSet())
+
+	return initCmd
+}

cmd/new_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 TestNewScriptCmd(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", "new"}
+			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 TestNewScriptCmd_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", "new"}
+	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 TestNewScriptCmd_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", "new", "-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() {")
+}

cmd/root.go

@@ -57,7 +57,7 @@ func newRootCommand(gs *state.GlobalState) *rootCommand {
 	rootCmd.SetIn(gs.Stdin)
 
 	subCommands := []func(*state.GlobalState) *cobra.Command{
-		getCmdArchive, getCmdCloud, getCmdInspect,
+		getCmdArchive, getCmdCloud, getCmdNewScript, getCmdInspect,
 		getCmdLogin, getCmdPause, getCmdResume, getCmdScale, getCmdRun,
 		getCmdStats, getCmdStatus, getCmdVersion,
 	}