[SEMVER] store SemVer in ForgejoSemVer after a database upgrade

(cherry picked from commit b7fe7cf401)
(cherry picked from commit cf339eed4f)
(cherry picked from commit 4f3a16168b)
(cherry picked from commit 6f5bbc53fc)

models/forgejo/semver/semver_test.go

@@ -0,0 +1,46 @@
+// SPDX-License-Identifier: MIT
+
+package semver
+
+import (
+	"testing"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/unittest"
+
+	"github.com/hashicorp/go-version"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestForgejoSemVerSetGet(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	ctx := db.DefaultContext
+
+	newVersion, err := version.NewVersion("v1.2.3")
+	assert.NoError(t, err)
+	assert.NoError(t, SetVersionString(ctx, newVersion.String()))
+	databaseVersion, err := GetVersion(ctx)
+	assert.NoError(t, err)
+	assert.EqualValues(t, newVersion.String(), databaseVersion.String())
+	assert.True(t, newVersion.Equal(databaseVersion))
+}
+
+func TestForgejoSemVerMissing(t *testing.T) {
+	assert.NoError(t, unittest.PrepareTestDatabase())
+	ctx := db.DefaultContext
+	e := db.GetEngine(ctx)
+
+	_, err := e.Exec("delete from forgejo_sem_ver")
+	assert.NoError(t, err)
+
+	v, err := GetVersion(ctx)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "1.0.0", v.String())
+
+	_, err = e.Exec("drop table forgejo_sem_ver")
+	assert.NoError(t, err)
+
+	v, err = GetVersion(ctx)
+	assert.NoError(t, err)
+	assert.EqualValues(t, "1.0.0", v.String())
+}