fix: maven fallback to parent groupId

modules/packages/maven/metadata.go

@@ -7,6 +7,7 @@ import (
 	"encoding/xml"
 	"io"
 
+	"code.gitea.io/gitea/modules/util"
 	"code.gitea.io/gitea/modules/validation"
 
 	"golang.org/x/net/html/charset"
@@ -49,8 +50,16 @@ type pomStruct struct {
 		Version    string `xml:"version"`
 		Scope      string `xml:"scope"`
 	} `xml:"dependencies>dependency"`
+	Parent struct {
+		GroupID      string `xml:"groupId"`
+		ArtifactID   string `xml:"artifactId"`
+		Version      string `xml:"version"`
+		RelativePath string `xml:"relativePath"`
+	} `xml:"parent"`
 }
 
+var ErrNoGroupID = util.NewInvalidArgumentErrorf("group ID is missing")
+
 // ParsePackageMetaData parses the metadata of a pom file
 func ParsePackageMetaData(r io.Reader) (*Metadata, error) {
 	var pom pomStruct
@@ -65,6 +74,17 @@ func ParsePackageMetaData(r io.Reader) (*Metadata, error) {
 		pom.URL = ""
 	}
 
+	groupID := pom.GroupID
+
+	if groupID == "" {
+		// If a project inherits from a parent project, the groupId element is optional.
+		// Refer to: https://maven.apache.org/pom.html#Inheritance
+		if pom.Parent.GroupID == "" {
+			return nil, ErrNoGroupID
+		}
+		groupID = pom.Parent.GroupID
+	}
+
 	licenses := make([]string, 0, len(pom.Licenses))
 	for _, l := range pom.Licenses {
 		if l.Name != "" {
@@ -82,7 +102,7 @@ func ParsePackageMetaData(r io.Reader) (*Metadata, error) {
 	}
 
 	return &Metadata{
-		GroupID:      pom.GroupID,
+		GroupID:      groupID,
 		ArtifactID:   pom.ArtifactID,
 		Name:         pom.Name,
 		Description:  pom.Description,

modules/packages/maven/metadata_test.go

@@ -14,6 +14,7 @@ import (
 
 const (
 	groupID              = "org.gitea"
+	parentGroupID        = "org.gitea.parent"
 	artifactID           = "my-project"
 	version              = "1.0.1"
 	name                 = "My Gitea Project"
@@ -27,6 +28,11 @@ const (
 
 const pomContent = `<?xml version="1.0"?>
 <project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <parent>
+    <groupId>` + parentGroupID + `</groupId>
+    <artifactId>parent-project</artifactId>
+    <version>1.0.0</version>
+  </parent>
   <groupId>` + groupID + `</groupId>
   <artifactId>` + artifactID + `</artifactId>
   <version>` + version + `</version>
@@ -47,6 +53,24 @@ const pomContent = `<?xml version="1.0"?>
   </dependencies>
 </project>`
 
+const pomWithParentGroupID = `<?xml version="1.0"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <parent>
+    <groupId>` + parentGroupID + `</groupId>
+    <artifactId>parent-project</artifactId>
+    <version>1.0.0</version>
+  </parent>
+
+  <artifactId>` + artifactID + `</artifactId>
+  <version>` + version + `</version>
+</project>`
+
+const pomWithMissingGroupID = `<?xml version="1.0"?>
+<project xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+  <artifactId>` + artifactID + `</artifactId>
+  <version>` + version + `</version>
+</project>`
+
 func TestParsePackageMetaData(t *testing.T) {
 	t.Run("InvalidFile", func(t *testing.T) {
 		m, err := ParsePackageMetaData(strings.NewReader(""))
@@ -87,4 +111,19 @@ func TestParsePackageMetaData(t *testing.T) {
 		require.NoError(t, err)
 		assert.NotNil(t, m)
 	})
+
+	t.Run("UseParentGroupID", func(t *testing.T) {
+		m, err := ParsePackageMetaData(strings.NewReader(pomWithParentGroupID))
+		require.NoError(t, err)
+		assert.NotNil(t, m)
+
+		assert.Equal(t, parentGroupID, m.GroupID)
+	})
+
+	t.Run("MissingGroupIDThrowsError", func(t *testing.T) {
+		m, err := ParsePackageMetaData(strings.NewReader(pomWithMissingGroupID))
+		assert.Nil(t, m)
+		require.Error(t, err)
+		assert.Equal(t, ErrNoGroupID, err)
+	})
 }