go

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runtime ​

Runtime introspection utilities.

Import ​

go
import runtimex "github.com/foomo/go/runtime"

API ​

Caller ​

go
func Caller(skip int) (shortName, fullName, file string, line int, ok bool)

Enriched wrapper around runtime.Caller. Returns the short function name (e.g. pkg.Func), the fully qualified name, a simplified file path (dir/file.go), and the line number. The skip parameter works like runtime.Caller — use 0 for the immediate caller.

CallerFunc ​

go
func CallerFunc(skip int) (string, bool)

Returns only the bare function name (without the package path or receiver) for the caller skip frames up the call stack. Returns "unknown", false if the caller cannot be determined.

StackTrace ​

go
func StackTrace(size, skip int) string

Captures and formats a stack trace of up to size frames, skipping the first skip frames. Both values are clamped to [0, 20]. Each frame is formatted as:

package.Function
  dir/file.go:42

Recover ​

go
func Recover(fn func()) error

Calls fn and converts any panic into a *PanicError. Returns nil if fn does not panic.

PanicError ​

go
type PanicError struct {
	Value any    // the original value passed to panic()
	Stack string // full stack trace at the point of the panic
}

func (e *PanicError) Error() string
func (e *PanicError) Unwrap() error

Represents a recovered panic with captured runtime context. Unwrap returns the panic value if it implements error, enabling errors.Is and errors.As to reach through the wrapper.

Examples ​

Caller ​

go
short, full, file, line, ok := runtimex.Caller(0)
fmt.Printf("%s (%s) at %s:%d\n", short, full, file, line)
// e.g. main.main (main.main) at main/main.go:12

CallerFunc ​

go
name, ok := runtimex.CallerFunc(0)
fmt.Println(name) // e.g. "main"

Recover ​

go
err := runtimex.Recover(func() {
	panic("something went wrong")
})

var pe *runtimex.PanicError
if errors.As(err, &pe) {
	fmt.Println(pe.Value) // "something went wrong"
	fmt.Println(pe.Stack) // full stack trace
}

StackTrace ​

go
trace := runtimex.StackTrace(5, 0)
fmt.Println(trace)
// main.handler
//   server/handler.go:28
// net/http.HandlerFunc.ServeHTTP
//   http/server.go:2136
// ...