From 1407fd3d4a00b5d05b81c6482604a9f58c7c8449 Mon Sep 17 00:00:00 2001
From: Blake Mizerany <blake.mizerany@gmail.com>
Date: Sun, 7 Apr 2024 10:25:44 -0700
Subject: [PATCH] x/model: Name: implement sql.Scanner and driver.Valuer

---
 x/model/name.go      | 34 +++++++++++++++++++++++++++++++++-
 x/model/name_test.go | 26 ++++++++++++++++++++++++++
 2 files changed, 59 insertions(+), 1 deletion(-)

diff --git a/x/model/name.go b/x/model/name.go
index 147e2acc..77ab08af 100644
--- a/x/model/name.go
+++ b/x/model/name.go
@@ -3,6 +3,8 @@ package model
 import (
 	"bytes"
 	"cmp"
+	"database/sql"
+	"database/sql/driver"
 	"errors"
 	"hash/maphash"
 	"io"
@@ -330,7 +332,7 @@ func (r *Name) UnmarshalText(text []byte) error {
 		// called on an invalid/zero Name. If we allow UnmarshalText
 		// on a valid Name, then the Name will be mutated, breaking
 		// the immutability of the Name.
-		return errors.New("model.Name: UnmarshalText on valid Name")
+		return errors.New("model.Name: illegal UnmarshalText on valid Name")
 	}
 
 	// The contract of UnmarshalText  is that we copy to keep the text.
@@ -338,6 +340,36 @@ func (r *Name) UnmarshalText(text []byte) error {
 	return nil
 }
 
+var (
+	_ driver.Valuer = Name{}
+	_ sql.Scanner   = (*Name)(nil)
+)
+
+// Scan implements [database/sql.Scanner].
+func (r *Name) Scan(src any) error {
+	if r.Valid() {
+		// The invariant of Scan is that it should only be called on an
+		// invalid/zero Name. If we allow Scan on a valid Name, then the
+		// Name will be mutated, breaking the immutability of the Name.
+		return errors.New("model.Name: illegal Scan on valid Name")
+
+	}
+	switch v := src.(type) {
+	case string:
+		*r = ParseName(v)
+		return nil
+	case []byte:
+		*r = ParseName(string(v))
+		return nil
+	}
+	return errors.New("model.Name: invalid Scan source")
+}
+
+// Value implements [database/sql/driver.Valuer].
+func (r Name) Value() (driver.Value, error) {
+	return r.String(), nil
+}
+
 // Complete reports whether the Name is fully qualified. That is it has a
 // domain, namespace, name, tag, and build.
 func (r Name) Complete() bool {
diff --git a/x/model/name_test.go b/x/model/name_test.go
index 94818511..16140a86 100644
--- a/x/model/name_test.go
+++ b/x/model/name_test.go
@@ -406,6 +406,32 @@ func TestNameTextUnmarshalCallOnValidName(t *testing.T) {
 	}
 }
 
+func TestSQL(t *testing.T) {
+	t.Run("Scan for already valid Name", func(t *testing.T) {
+		p := mustParse("x")
+		if err := p.Scan("mistral:latest+Q4_0"); err == nil {
+			t.Error("Scan() = nil; want error")
+		}
+	})
+	t.Run("Scan for invalid Name", func(t *testing.T) {
+		p := Name{}
+		if err := p.Scan("mistral:latest+Q4_0"); err != nil {
+			t.Errorf("Scan() = %v; want nil", err)
+		}
+		if p.String() != "mistral:latest+Q4_0" {
+			t.Errorf("String() = %q; want %q", p, "mistral:latest+Q4_0")
+		}
+	})
+	t.Run("Value", func(t *testing.T) {
+		p := mustParse("x")
+		if g, err := p.Value(); err != nil {
+			t.Errorf("Value() error = %v; want nil", err)
+		} else if g != "x" {
+			t.Errorf("Value() = %q; want %q", g, "x")
+		}
+	})
+}
+
 func TestNameTextMarshalAllocs(t *testing.T) {
 	var data []byte
 	name := ParseName("example.com/ns/mistral:latest+Q4_0")