Add support for Pub packages (#20560)

* Added support for Pub packages.

* Update docs/content/doc/packages/overview.en-us.md

Co-authored-by: Gergely Nagy <algernon@users.noreply.github.com>

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>
Co-authored-by: Gergely Nagy <algernon@users.noreply.github.com>
Co-authored-by: Lauris BH <lauris@nix.lv>

modules/packages/pub/metadata_test.go

@@ -0,0 +1,136 @@
+// Copyright 2022 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package pub
+
+import (
+	"archive/tar"
+	"bytes"
+	"compress/gzip"
+	"io"
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+const (
+	packageName      = "gitea"
+	packageVersion   = "1.0.1"
+	description      = "Package Description"
+	projectURL       = "https://gitea.io"
+	repositoryURL    = "https://gitea.io/gitea/gitea"
+	documentationURL = "https://docs.gitea.io"
+)
+
+const pubspecContent = `name: ` + packageName + `
+version: ` + packageVersion + `
+description: ` + description + `
+homepage: ` + projectURL + `
+repository: ` + repositoryURL + `
+documentation: ` + documentationURL + `
+
+environment:
+  sdk: '>=2.16.0 <3.0.0'
+
+dependencies:
+  flutter:
+    sdk: flutter
+  path: '>=1.8.0 <3.0.0'
+
+dev_dependencies:
+  http: '>=0.13.0'`
+
+func TestParsePackage(t *testing.T) {
+	createArchive := func(files map[string][]byte) io.Reader {
+		var buf bytes.Buffer
+		zw := gzip.NewWriter(&buf)
+		tw := tar.NewWriter(zw)
+		for filename, content := range files {
+			hdr := &tar.Header{
+				Name: filename,
+				Mode: 0o600,
+				Size: int64(len(content)),
+			}
+			tw.WriteHeader(hdr)
+			tw.Write(content)
+		}
+		tw.Close()
+		zw.Close()
+		return &buf
+	}
+
+	t.Run("MissingPubspecFile", func(t *testing.T) {
+		data := createArchive(map[string][]byte{"dummy.txt": {}})
+
+		pp, err := ParsePackage(data)
+		assert.Nil(t, pp)
+		assert.ErrorIs(t, err, ErrMissingPubspecFile)
+	})
+
+	t.Run("PubspecFileTooLarge", func(t *testing.T) {
+		data := createArchive(map[string][]byte{"pubspec.yaml": make([]byte, 200*1024)})
+
+		pp, err := ParsePackage(data)
+		assert.Nil(t, pp)
+		assert.ErrorIs(t, err, ErrPubspecFileTooLarge)
+	})
+
+	t.Run("InvalidPubspecFile", func(t *testing.T) {
+		data := createArchive(map[string][]byte{"pubspec.yaml": {}})
+
+		pp, err := ParsePackage(data)
+		assert.Nil(t, pp)
+		assert.Error(t, err)
+	})
+
+	t.Run("Valid", func(t *testing.T) {
+		data := createArchive(map[string][]byte{"pubspec.yaml": []byte(pubspecContent)})
+
+		pp, err := ParsePackage(data)
+		assert.NoError(t, err)
+		assert.NotNil(t, pp)
+		assert.Empty(t, pp.Metadata.Readme)
+	})
+
+	t.Run("ValidWithReadme", func(t *testing.T) {
+		data := createArchive(map[string][]byte{"pubspec.yaml": []byte(pubspecContent), "README.md": []byte("readme")})
+
+		pp, err := ParsePackage(data)
+		assert.NoError(t, err)
+		assert.NotNil(t, pp)
+		assert.Equal(t, "readme", pp.Metadata.Readme)
+	})
+}
+
+func TestParsePubspecMetadata(t *testing.T) {
+	t.Run("InvalidName", func(t *testing.T) {
+		for _, name := range []string{"123abc", "ab-cd"} {
+			pp, err := ParsePubspecMetadata(strings.NewReader(`name: ` + name))
+			assert.Nil(t, pp)
+			assert.ErrorIs(t, err, ErrInvalidName)
+		}
+	})
+
+	t.Run("InvalidVersion", func(t *testing.T) {
+		pp, err := ParsePubspecMetadata(strings.NewReader(`name: dummy
+version: invalid`))
+		assert.Nil(t, pp)
+		assert.ErrorIs(t, err, ErrInvalidVersion)
+	})
+
+	t.Run("Valid", func(t *testing.T) {
+		pp, err := ParsePubspecMetadata(strings.NewReader(pubspecContent))
+		assert.NoError(t, err)
+		assert.NotNil(t, pp)
+
+		assert.Equal(t, packageName, pp.Name)
+		assert.Equal(t, packageVersion, pp.Version)
+		assert.Equal(t, description, pp.Metadata.Description)
+		assert.Equal(t, projectURL, pp.Metadata.ProjectURL)
+		assert.Equal(t, repositoryURL, pp.Metadata.RepositoryURL)
+		assert.Equal(t, documentationURL, pp.Metadata.DocumentationURL)
+		assert.NotNil(t, pp.Metadata.Pubspec)
+	})
+}