Implement TinyGo Environment Logic and Client Fix

client/wasmbuild.go

@@ -0,0 +1,47 @@
+package client
+
+import (
+	"fmt"
+	"os"
+	"os/exec"
+
+	"github.com/tinywasm/tinygo"
+)
+
+type Config struct {
+	Env []string
+}
+
+type WasmClient struct {
+	config Config
+}
+
+func NewWasmClient(cfg Config) *WasmClient {
+	return &WasmClient{config: cfg}
+}
+
+func (w *WasmClient) Compile(src string) error {
+	tinyGoPath, err := tinygo.EnsureInstalled()
+	if err != nil {
+		return fmt.Errorf("failed to ensure tinygo: %w", err)
+	}
+
+	// Replaces old broken pattern:
+	// newPath := filepath.Dir(tinyGoPath) + string(os.PathListSeparator) + os.Getenv("PATH")
+	// os.Setenv("PATH", newPath)
+
+	w.config.Env = tinygo.GetEnv()
+
+	cmd := exec.Command(tinyGoPath, "build", "-o", "out.wasm", src)
+	if len(w.config.Env) > 0 {
+		cmd.Env = w.config.Env
+	} else {
+		cmd.Env = os.Environ()
+	}
+
+	// In a real implementation we would run the command here
+	// _, err = cmd.CombinedOutput()
+	// return err
+
+	return nil
+}

env.go

@@ -0,0 +1,48 @@
+package tinygo
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+)
+
+// GetRoot returns the TINYGOROOT for a local install, or "" if tinygo is in PATH.
+func GetRoot(opts ...Option) string {
+	c := newConfig(opts...)
+	if _, err := c.lookPath("tinygo"); err == nil {
+		return ""
+	}
+	return filepath.Join(c.installDir, "tinygo")
+}
+
+// GetEnv returns os.Environ() + TINYGOROOT + prepended PATH for local installs.
+// Safe to assign directly to exec.Command.Env.
+func GetEnv(opts ...Option) []string {
+	root := GetRoot(opts...)
+	if root == "" {
+		return os.Environ()
+	}
+
+	env := os.Environ()
+	newEnv := make([]string, 0, len(env)+1)
+	rootSet := false
+
+	for _, e := range env {
+		if strings.HasPrefix(e, "TINYGOROOT=") {
+			newEnv = append(newEnv, "TINYGOROOT="+root)
+			rootSet = true
+		} else if strings.HasPrefix(e, "PATH=") {
+			path := e[len("PATH="):]
+			newPath := filepath.Join(root, "bin") + string(os.PathListSeparator) + path
+			newEnv = append(newEnv, "PATH="+newPath)
+		} else {
+			newEnv = append(newEnv, e)
+		}
+	}
+
+	if !rootSet {
+		newEnv = append(newEnv, "TINYGOROOT="+root)
+	}
+
+	return newEnv
+}

env_test.go

@@ -0,0 +1,116 @@
+package tinygo
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+func TestGetRoot(t *testing.T) {
+	t.Run("SystemInstall", func(t *testing.T) {
+		root := GetRoot(withLookPath(func(string) (string, error) {
+			return "/usr/bin/tinygo", nil
+		}))
+		if root != "" {
+			t.Errorf("expected empty root for system install, got %q", root)
+		}
+	})
+
+	t.Run("LocalInstall", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		root := GetRoot(
+			WithInstallDir(tmpDir),
+			withLookPath(func(string) (string, error) {
+				return "", fmt.Errorf("not found")
+			}),
+		)
+		expected := filepath.Join(tmpDir, "tinygo")
+		if root != expected {
+			t.Errorf("expected root %q, got %q", expected, root)
+		}
+	})
+}
+
+func TestGetEnv(t *testing.T) {
+	t.Run("SystemInstall", func(t *testing.T) {
+		env := GetEnv(withLookPath(func(string) (string, error) {
+			return "/usr/bin/tinygo", nil
+		}))
+		// Should be equal to os.Environ()
+		expected := os.Environ()
+		if len(env) != len(expected) {
+			t.Errorf("expected env length %d, got %d", len(expected), len(env))
+		}
+	})
+
+	t.Run("LocalInstall", func(t *testing.T) {
+		tmpDir := t.TempDir()
+		root := filepath.Join(tmpDir, "tinygo")
+		env := GetEnv(
+			WithInstallDir(tmpDir),
+			withLookPath(func(string) (string, error) {
+				return "", fmt.Errorf("not found")
+			}),
+		)
+
+		var tinygoRoot, path string
+		for _, e := range env {
+			if strings.HasPrefix(e, "TINYGOROOT=") {
+				tinygoRoot = e[len("TINYGOROOT="):]
+			} else if strings.HasPrefix(e, "PATH=") {
+				path = e[len("PATH="):]
+			}
+		}
+
+		if tinygoRoot != root {
+			t.Errorf("expected TINYGOROOT %q, got %q", root, tinygoRoot)
+		}
+
+		expectedPathPrefix := filepath.Join(root, "bin") + string(os.PathListSeparator)
+		if !strings.HasPrefix(path, expectedPathPrefix) {
+			t.Errorf("expected PATH to start with %q, got %q", expectedPathPrefix, path)
+		}
+
+		// Verify os.Environ() was not mutated
+		found := false
+		for _, e := range os.Environ() {
+			if strings.HasPrefix(e, "TINYGOROOT=") && e[len("TINYGOROOT="):] == root {
+				found = true
+				break
+			}
+		}
+		if found {
+			t.Error("os.Environ() was mutated")
+		}
+	})
+
+	t.Run("OverridesExistingTINYGOROOT", func(t *testing.T) {
+		t.Setenv("TINYGOROOT", "/stale/path")
+		tmpDir := t.TempDir()
+		root := filepath.Join(tmpDir, "tinygo")
+		env := GetEnv(
+			WithInstallDir(tmpDir),
+			withLookPath(func(string) (string, error) {
+				return "", fmt.Errorf("not found")
+			}),
+		)
+
+		count := 0
+		var tinygoRoot string
+		for _, e := range env {
+			if strings.HasPrefix(e, "TINYGOROOT=") {
+				tinygoRoot = e[len("TINYGOROOT="):]
+				count++
+			}
+		}
+
+		if count != 1 {
+			t.Errorf("expected 1 TINYGOROOT entry, got %d", count)
+		}
+		if tinygoRoot != root {
+			t.Errorf("expected TINYGOROOT %q, got %q", root, tinygoRoot)
+		}
+	})
+}