Add k6-gleam plugin

Signed-off-by: Thanabodee Charoenpiriyakij <[email protected]>

xk6-gleam/.gitignore

@@ -0,0 +1 @@
+/k6

xk6-gleam/go.mod

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+module github.com/tsloughter/k6_gleam/k6-gleam
+
+go 1.22.2
+
+require (
+	github.com/BurntSushi/toml v1.3.2
+	github.com/grafana/k6pack v0.1.5
+	go.k6.io/k6 v0.51.0
+)
+
+require (
+	github.com/evanw/esbuild v0.20.2 // indirect
+	github.com/onsi/ginkgo v1.16.5 // indirect
+	github.com/onsi/gomega v1.33.1 // indirect
+)
+
+require (
+	github.com/cenkalti/backoff/v4 v4.2.1 // indirect
+	github.com/dlclark/regexp2 v1.9.0 // indirect
+	github.com/dop251/goja v0.0.0-20240220182346-e401ed450204 // indirect
+	github.com/fatih/color v1.16.0 // indirect
+	github.com/go-logr/logr v1.4.1 // indirect
+	github.com/go-logr/stdr v1.2.2 // indirect
+	github.com/go-sourcemap/sourcemap v2.1.4+incompatible // indirect
+	github.com/google/pprof v0.0.0-20240424215950-a892ee059fd6 // indirect
+	github.com/grpc-ecosystem/grpc-gateway/v2 v2.19.0 // indirect
+	github.com/josharian/intern v1.0.0 // indirect
+	github.com/mailru/easyjson v0.7.7 // indirect
+	github.com/mattn/go-colorable v0.1.13 // indirect
+	github.com/mattn/go-isatty v0.0.20 // indirect
+	github.com/mstoykov/atlas v0.0.0-20220811071828-388f114305dd // indirect
+	github.com/serenize/snaker v0.0.0-20201027110005-a7ad2135616e // indirect
+	github.com/sirupsen/logrus v1.9.3
+	github.com/spf13/afero v1.1.2 // indirect
+	go.opentelemetry.io/otel v1.24.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace v1.24.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracegrpc v1.24.0 // indirect
+	go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp v1.24.0 // indirect
+	go.opentelemetry.io/otel/metric v1.24.0 // indirect
+	go.opentelemetry.io/otel/sdk v1.24.0 // indirect
+	go.opentelemetry.io/otel/trace v1.24.0 // indirect
+	go.opentelemetry.io/proto/otlp v1.1.0 // indirect
+	golang.org/x/net v0.24.0 // indirect
+	golang.org/x/sys v0.19.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	golang.org/x/time v0.5.0 // indirect
+	google.golang.org/genproto/googleapis/api v0.0.0-20240227224415-6ceb2ff114de // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20240227224415-6ceb2ff114de // indirect
+	google.golang.org/grpc v1.63.2 // indirect
+	google.golang.org/protobuf v1.33.0 // indirect
+	gopkg.in/guregu/null.v3 v3.3.0 // indirect
+)

xk6-gleam/internal/gleam/gleam.go

@@ -0,0 +1,36 @@
+package gleam
+
+import (
+	"os"
+	"os/exec"
+	"path/filepath"
+
+	"github.com/BurntSushi/toml"
+)
+
+// Build run build command.
+func Build() error {
+	// Ensure always build with js target.
+	cmd := exec.Command("gleam", "build", "--target", "javascript")
+	cmd.Stderr = os.Stderr
+	cmd.Stdin = os.Stdin
+	cmd.Stdout = os.Stdout
+	return cmd.Run()
+}
+
+// ProjectName returns a project name defined in `gleam.toml`.
+func ProjectName(cwd string) (string, error) {
+	tm, err := os.ReadFile(filepath.Join(cwd, "gleam.toml"))
+	if err != nil {
+		return "", err
+	}
+
+	gleamToml := struct {
+		Name string `toml:"name"`
+	}{}
+	if err := toml.Unmarshal(tm, &gleamToml); err != nil {
+		return "", err
+	}
+
+	return gleamToml.Name, nil
+}

xk6-gleam/loader.go

@@ -0,0 +1,119 @@
+package k6_gleam
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/grafana/k6pack"
+	"github.com/sirupsen/logrus"
+	"github.com/tsloughter/k6_gleam/k6-gleam/internal/gleam"
+)
+
+func init() {
+	redirectStdin()
+}
+
+// Copied from https://github.com/grafana/xk6-ts/blob/master/loader.go#L17
+func isRunCommand(args []string) (bool, int) {
+	argn := len(args)
+
+	scriptIndex := argn - 1
+	if scriptIndex < 0 {
+		return false, scriptIndex
+	}
+
+	var runIndex int
+
+	for idx := 0; idx < argn; idx++ {
+		arg := args[idx]
+		if arg == "run" && runIndex == 0 {
+			runIndex = idx
+
+			break
+		}
+	}
+
+	if runIndex == 0 {
+		return false, -1
+	}
+
+	return true, scriptIndex
+}
+
+// Uses script from `run` sub-command and transpile gleam into js and load it back
+// to `k6` using stdin option.
+func redirectStdin() {
+	isRun, scriptIndex := isRunCommand(os.Args)
+	if !isRun {
+		return
+	}
+
+	// TODO: detect .gleam extension.
+	filename := os.Args[scriptIndex]
+
+	logrus.Infof("Get script named %s", filename)
+	logrus.Info("Build a gleam project...")
+
+	if err := gleam.Build(); err != nil {
+		logrus.WithError(err).Fatal()
+	}
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		logrus.WithError(err).Fatal()
+	}
+
+	logrus.Info("Bundling...")
+
+	filename, contents, err := jsBuildFile(cwd, filename)
+	if err != nil {
+		logrus.WithError(err).Fatal()
+	}
+
+	opts := k6pack.Options{
+		Filename:   filename,
+		SourceRoot: cwd,
+	}
+
+	jsScript, err := k6pack.Pack(string(addRuntime(contents)), &opts)
+	if err != nil {
+		logrus.WithError(err).Fatal()
+	}
+
+	os.Args[scriptIndex] = "-"
+
+	reader, writer, err := os.Pipe()
+	if err != nil {
+		logrus.WithError(err).Fatal()
+	}
+
+	os.Stdin = reader
+
+	go func() {
+		_, werr := writer.Write(jsScript)
+		writer.Close()
+
+		if err != nil {
+			logrus.WithError(werr).Fatal("stdin redirect failed")
+		}
+	}()
+}
+
+func addRuntime(source []byte) []byte {
+	runtime := "\nexport default main;\n"
+	return append(source, []byte(runtime)...)
+}
+
+// Convert gleam input filename into javascript file path.
+func jsBuildFile(cwd, gleamFilename string) (filename string, contents []byte, err error) {
+	filename = filepath.Base(gleamFilename)
+	projName, err := gleam.ProjectName(cwd)
+	if err != nil {
+		return "", nil, err
+	}
+	// TODO: support more than dev?
+	filename = filepath.Join(cwd, "build", "dev", "javascript", projName, strings.TrimRight(filename, ".gleam")+".mjs")
+	contents, err = os.ReadFile(filename)
+	return
+}

xk6-gleam/plugin.go

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+package k6_gleam
+
+import "go.k6.io/k6/js/modules"
+
+type extension struct{}
+
+func init() {
+	modules.Register("k6/x/gleam", extension{})
+}