Add Go package registry (#24687)

Fixes #7608

This PR adds a Go package registry usable with the Go proxy protocol.

![grafik](https://github.com/go-gitea/gitea/assets/1666336/328feb5c-3df2-4f9d-8eae-fe3126d14c37)

1 files changed, 75 insertions, 0 deletions

diff --git a/modules/packages/goproxy/metadata_test.go b/modules/packages/goproxy/metadata_test.go
new file mode 100644
index 0000000000..4e7f394f8b
--- /dev/null
+++ b/modules/packages/goproxy/metadata_test.go
@@ -0,0 +1,75 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package goproxy
+
+import (
+	"archive/zip"
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	packageName    = "gitea.com/go-gitea/gitea"
+	packageVersion = "v0.0.1"
+)
+
+func TestParsePackage(t *testing.T) {
+	createArchive := func(files map[string][]byte) *bytes.Reader {
+		var buf bytes.Buffer
+		zw := zip.NewWriter(&buf)
+		for name, content := range files {
+			w, _ := zw.Create(name)
+			w.Write(content)
+		}
+		zw.Close()
+		return bytes.NewReader(buf.Bytes())
+	}
+
+	t.Run("EmptyPackage", func(t *testing.T) {
+		data := createArchive(nil)
+
+		p, err := ParsePackage(data, int64(data.Len()))
+		assert.Nil(t, p)
+		assert.ErrorIs(t, err, ErrInvalidStructure)
+	})
+
+	t.Run("InvalidNameOrVersionStructure", func(t *testing.T) {
+		data := createArchive(map[string][]byte{
+			packageName + "/" + packageVersion + "/go.mod": {},
+		})
+
+		p, err := ParsePackage(data, int64(data.Len()))
+		assert.Nil(t, p)
+		assert.ErrorIs(t, err, ErrInvalidStructure)
+	})
+
+	t.Run("GoModFileInWrongDirectory", func(t *testing.T) {
+		data := createArchive(map[string][]byte{
+			packageName + "@" + packageVersion + "/subdir/go.mod": {},
+		})
+
+		p, err := ParsePackage(data, int64(data.Len()))
+		assert.NotNil(t, p)
+		assert.NoError(t, err)
+		assert.Equal(t, packageName, p.Name)
+		assert.Equal(t, packageVersion, p.Version)
+		assert.Equal(t, "module gitea.com/go-gitea/gitea", p.GoMod)
+	})
+
+	t.Run("Valid", func(t *testing.T) {
+		data := createArchive(map[string][]byte{
+			packageName + "@" + packageVersion + "/subdir/go.mod": []byte("invalid"),
+			packageName + "@" + packageVersion + "/go.mod":        []byte("valid"),
+		})
+
+		p, err := ParsePackage(data, int64(data.Len()))
+		assert.NotNil(t, p)
+		assert.NoError(t, err)
+		assert.Equal(t, packageName, p.Name)
+		assert.Equal(t, packageVersion, p.Version)
+		assert.Equal(t, "valid", p.GoMod)
+	})
+}