add lib/pq

vendor/github.com/lib/pq/as.go

@@ -0,0 +1,26 @@
+//go:build !go1.26
+
+package pq
+
+import (
+	"errors"
+	"slices"
+)
+
+// As asserts that the given error is [pq.Error] and returns it, returning nil
+// if it's not a pq.Error.
+//
+// It will return nil if the pq.Error is not one of the given error codes. If no
+// codes are given it will always return the Error.
+//
+// This is safe to call with a nil error.
+func As(err error, codes ...ErrorCode) *Error {
+	if err == nil { // Not strictly needed, but prevents alloc for nil errors.
+		return nil
+	}
+	pqErr := new(Error)
+	if errors.As(err, &pqErr) && (len(codes) == 0 || slices.Contains(codes, pqErr.Code)) {
+		return pqErr
+	}
+	return nil
+}