🚨 Sentinel Errors

pkg/cvss/errors.go · 4 exported sentinel errors

Structured validation errors (ValidationError / ValidationErrors) live in pkg/cvss/validate.go and are documented at /sdk/validation. This page covers only the four sentinel errors declared in errors.go.

Synopsis

errors.go declares four package-level sentinel error variables so callers can match them with errors.Is instead of string comparison. ErrNilReceiver is returned throughout the SDK (the With* method-chain helpers in pkg/cvss/with_method.go, plus batch.go, score_range.go, accessor.go, conversion.go and impact.go). The other three — ErrIncompleteBaseMetrics, ErrUnsupportedVersion, ErrInvalidMetricValue — are exported as stable sentinels for callers to use/compare against; note that the SDK's own Check() and Calculator currently report equivalent conditions via fmt.Errorf strings rather than wrapping these sentinels, so errors.Is on those code paths will not match them. They are intended for application-level error classification and for any code that wants to wrap/return a canonical CVSS error.

var cv *cvss.Cvss3x // nil
_, err := cv.WithAVMethod('N')
if errors.Is(err, cvss.ErrNilReceiver) {
    // handle nil-receiver case
}

How It Works

The four sentinels are stable values for errors.Is matching. ErrNilReceiver is returned directly by the nil-guarded methods across the SDK; the other three are exported as canonical classifiers — application code can wrap/return them, while the SDK's own Check()/Calculator paths report equivalent conditions via fmt.Errorf strings that do not wrap these sentinels.

API Reference

var (
    ErrNilReceiver          = errors.New("nil receiver")
    ErrIncompleteBaseMetrics = errors.New("incomplete base metrics")
    ErrUnsupportedVersion   = errors.New("unsupported CVSS version")
    ErrInvalidMetricValue   = errors.New("invalid metric value")
)

Sentinel	Error() text	Intended meaning
ErrNilReceiver	nil receiver	A method was invoked on a nil *Cvss3x (or nil sub-receiver). Returned by the With* method-chain helpers, batch helpers, GetScoreRange, accessors, conversion and impact helpers when their receiver is nil.
ErrIncompleteBaseMetrics	incomplete base metrics	The base metrics are not fully populated. Exported as a canonical sentinel; the SDK's own Check() reports the same condition via fmt.Errorf strings, so match by sentinel only if your code returns/wraps this value.
ErrUnsupportedVersion	unsupported CVSS version	The CVSS version is not one the SDK supports (only 3.0 and 3.1). Exported as a canonical sentinel; Cvss3x.Check() reports the same condition via fmt.Errorf.
ErrInvalidMetricValue	invalid metric value	A metric carries a value that is not legal for its category. Exported as a canonical sentinel for application-level classification.

All four are plain errors.New values — wrap-free and safe to compare with errors.Is.

Example

package main

import (
	"errors"
	"fmt"

	"github.com/scagogogo/cvss-skills/pkg/cvss"
)

func main() {
	var cv *cvss.Cvss3x // nil

	_, err := cv.WithAVMethod('N')
	switch {
	case errors.Is(err, cvss.ErrNilReceiver):
		fmt.Println("receiver was nil, skip")
	case errors.Is(err, cvss.ErrIncompleteBaseMetrics):
		fmt.Println("base metrics incomplete")
	case errors.Is(err, cvss.ErrUnsupportedVersion):
		fmt.Println("unsupported version")
	case errors.Is(err, cvss.ErrInvalidMetricValue):
		fmt.Println("invalid metric value")
	default:
		fmt.Println("other error:", err)
	}
}

Related

• /sdk/validation — ValidationError / ValidationErrors and the Check / Validate entry points
• /sdk/cvss — the Cvss3x type whose methods return these sentinels
• /sdk/calculator — scoring helpers that surface ErrNilReceiver / ErrIncompleteBaseMetrics