Add invopop/jsonschema fork

vendor/github.com/karimkhaleel/jsonschema/id.go

@@ -0,0 +1,76 @@
+package jsonschema
+
+import (
+	"errors"
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+// ID represents a Schema ID type which should always be a URI.
+// See draft-bhutton-json-schema-00 section 8.2.1
+type ID string
+
+// EmptyID is used to explicitly define an ID with no value.
+const EmptyID ID = ""
+
+// Validate is used to check if the ID looks like a proper schema.
+// This is done by parsing the ID as a URL and checking it has all the
+// relevant parts.
+func (id ID) Validate() error {
+	u, err := url.Parse(id.String())
+	if err != nil {
+		return fmt.Errorf("invalid URL: %w", err)
+	}
+	if u.Hostname() == "" {
+		return errors.New("missing hostname")
+	}
+	if !strings.Contains(u.Hostname(), ".") {
+		return errors.New("hostname does not look valid")
+	}
+	if u.Path == "" {
+		return errors.New("path is expected")
+	}
+	if u.Scheme != "https" && u.Scheme != "http" {
+		return errors.New("unexpected schema")
+	}
+	return nil
+}
+
+// Anchor sets the anchor part of the schema URI.
+func (id ID) Anchor(name string) ID {
+	b := id.Base()
+	return ID(b.String() + "#" + name)
+}
+
+// Def adds or replaces a definition identifier.
+func (id ID) Def(name string) ID {
+	b := id.Base()
+	return ID(b.String() + "#/$defs/" + name)
+}
+
+// Add appends the provided path to the id, and removes any
+// anchor data that might be there.
+func (id ID) Add(path string) ID {
+	b := id.Base()
+	if !strings.HasPrefix(path, "/") {
+		path = "/" + path
+	}
+	return ID(b.String() + path)
+}
+
+// Base removes any anchor information from the schema
+func (id ID) Base() ID {
+	s := id.String()
+	i := strings.LastIndex(s, "#")
+	if i != -1 {
+		s = s[0:i]
+	}
+	s = strings.TrimRight(s, "/")
+	return ID(s)
+}
+
+// String provides string version of ID
+func (id ID) String() string {
+	return string(id)
+}