Add Wails CLI install/detection helper

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

internal/wails/cli.go

@@ -0,0 +1,41 @@
+package wails
+
+import (
+	"context"
+	"fmt"
+	"regexp"
+	"strings"
+
+	"github.com/leonmika/wails-release/internal/runner"
+)
+
+var cliVersionRE = regexp.MustCompile(`v\d+\.\d+\.\d+`)
+
+// ParseCLIVersion extracts the version from `wails -v` output.
+func ParseCLIVersion(out []byte) (string, error) {
+	m := cliVersionRE.FindString(strings.TrimSpace(string(out)))
+	if m == "" {
+		return "", fmt.Errorf("could not parse Wails CLI version from %q", string(out))
+	}
+	return m, nil
+}
+
+// EnsureCLI installs the Wails CLI at `want` (e.g. "v2.11.0") if it is not
+// already installed at exactly that version.
+func EnsureCLI(ctx context.Context, r runner.Runner, want string) error {
+	out, err := r.Run(ctx, runner.Spec{Name: "wails", Args: []string{"-v"}})
+	if err == nil {
+		got, perr := ParseCLIVersion(out)
+		if perr == nil && got == want {
+			return nil
+		}
+	}
+	_, err = r.Run(ctx, runner.Spec{
+		Name: "go",
+		Args: []string{"install", "github.com/wailsapp/wails/v2/cmd/wails@" + want},
+	})
+	if err != nil {
+		return fmt.Errorf("install wails CLI %s: %w", want, err)
+	}
+	return nil
+}

internal/wails/cli_test.go

@@ -0,0 +1,83 @@
+package wails_test
+
+import (
+	"context"
+	"errors"
+	"strings"
+	"testing"
+
+	"github.com/leonmika/wails-release/internal/runner"
+	"github.com/leonmika/wails-release/internal/wails"
+)
+
+func TestParseInstalledVersion(t *testing.T) {
+	cases := map[string]string{
+		"Wails CLI v2.11.0":                                      "v2.11.0",
+		"Wails CLI v2.10.1\n":                                    "v2.10.1",
+		"Wails v2.9.0":                                           "v2.9.0",
+	}
+	for in, want := range cases {
+		got, err := wails.ParseCLIVersion([]byte(in))
+		if err != nil {
+			t.Fatalf("unexpected error parsing %q: %v", in, err)
+		}
+		if got != want {
+			t.Fatalf("input %q: got %q want %q", in, got, want)
+		}
+	}
+}
+
+func TestParseInstalledVersion_Unparseable(t *testing.T) {
+	_, err := wails.ParseCLIVersion([]byte("nope"))
+	if err == nil {
+		t.Fatal("expected error")
+	}
+}
+
+func TestEnsureCLI_AlreadyInstalledMatchingSkipsInstall(t *testing.T) {
+	f := &runner.Fake{}
+	f.On("wails", []string{"-v"}).Return([]byte("Wails CLI v2.11.0"), nil)
+
+	err := wails.EnsureCLI(context.Background(), f, "v2.11.0")
+	if err != nil {
+		t.Fatalf("unexpected: %v", err)
+	}
+
+	for _, c := range f.Calls {
+		if c.Name == "go" {
+			t.Fatalf("expected no `go install`, got call: %+v", c)
+		}
+	}
+}
+
+func TestEnsureCLI_MismatchTriggersInstall(t *testing.T) {
+	f := &runner.Fake{}
+	f.On("wails", []string{"-v"}).Return([]byte("Wails CLI v2.10.0"), nil)
+	f.On("go", []string{"install", "github.com/wailsapp/wails/v2/cmd/wails@v2.11.0"}).Return(nil, nil)
+
+	err := wails.EnsureCLI(context.Background(), f, "v2.11.0")
+	if err != nil {
+		t.Fatalf("unexpected: %v", err)
+	}
+
+	saw := false
+	for _, c := range f.Calls {
+		if c.Name == "go" && c.Args[0] == "install" && strings.Contains(c.Args[1], "@v2.11.0") {
+			saw = true
+		}
+	}
+	if !saw {
+		t.Fatal("expected go install call, did not see one")
+	}
+}
+
+func TestEnsureCLI_NotInstalledTriggersInstall(t *testing.T) {
+	f := &runner.Fake{}
+	f.On("wails", []string{"-v"}).Return(nil, errors.New("exec: not found"))
+	f.On("go", []string{"install", "github.com/wailsapp/wails/v2/cmd/wails@v2.11.0"}).Return(nil, nil)
+
+	err := wails.EnsureCLI(context.Background(), f, "v2.11.0")
+	if err != nil {
+		t.Fatalf("unexpected: %v", err)
+	}
+}