[v3] Improve init command

v3/internal/debug/debug.go

@@ -0,0 +1,56 @@
+package debug
+
+import (
+	"github.com/samber/lo"
+	"path/filepath"
+	"runtime"
+)
+
+import "runtime/debug"
+
+// Why go doesn't provide this as a map already is beyond me.
+var buildSettings = map[string]string{}
+var LocalModulePath = ""
+
+func init() {
+	buildInfo, ok := debug.ReadBuildInfo()
+	if !ok {
+		return
+	}
+	buildSettings = lo.Associate(buildInfo.Settings, func(setting debug.BuildSetting) (string, string) {
+		return setting.Key, setting.Value
+	})
+	if isLocalBuild() {
+		modulePath := RelativePath("..", "..", "..")
+		LocalModulePath, _ = filepath.Abs(modulePath)
+	}
+}
+
+func isLocalBuild() bool {
+	return buildSettings["vcs.modified"] == "true"
+}
+
+// RelativePath returns a qualified path created by joining the
+// directory of the calling file and the given relative path.
+//
+// Example: RelativePath("..") in *this* file would give you '/path/to/wails2/v2/internal`
+func RelativePath(relativepath string, optionalpaths ...string) string {
+	_, thisFile, _, _ := runtime.Caller(1)
+	localDir := filepath.Dir(thisFile)
+
+	// If we have optional paths, join them to the relativepath
+	if len(optionalpaths) > 0 {
+		paths := []string{relativepath}
+		paths = append(paths, optionalpaths...)
+		relativepath = filepath.Join(paths...)
+	}
+	result, err := filepath.Abs(filepath.Join(localDir, relativepath))
+	if err != nil {
+		// I'm allowing this for 1 reason only: It's fatal if the path
+		// supplied is wrong as it's only used internally in Wails. If we get
+		// that path wrong, we should know about it immediately. The other reason is
+		// that it cuts down a ton of unnecassary error handling.
+		panic(err)
+	}
+	return result
+}