fix: skip archive files when detecting packed licenses

Author: nikpivkin

pkg/dependency/parser/java/jar/export_test.go

@@ -5,4 +5,5 @@ package jar
 var (
 	EmbeddedPomGAV    = embeddedPomGAV
 	DecodePomLicenses = decodePomLicenses
+	IsJarLicenseFile  = isJarLicenseFile
 )

pkg/dependency/parser/java/jar/parse.go

@@ -490,6 +490,9 @@ func isJarLicenseFile(name string) bool {
 		return false
 	}
 	base := path.Base(name)
+	if isArtifact(base) {
+		return false // e.g. license.jar is a nested archive, not a license file
+	}
 	stem := strings.TrimSuffix(base, path.Ext(base))
 	return licenseFileStems.Contains(stem)
 }

pkg/dependency/parser/java/jar/parse_test.go

@@ -451,3 +451,62 @@ func TestDecodePomLicenses(t *testing.T) {
 		})
 	}
 }
+
+func TestIsJarLicenseFile(t *testing.T) {
+	tests := []struct {
+		name string
+		path string
+		want bool
+	}{
+		{
+			name: "LICENSE at root",
+			path: "LICENSE",
+			want: true,
+		},
+		{
+			name: "LICENSE.txt at root",
+			path: "LICENSE.txt",
+			want: true,
+		},
+		{
+			name: "license under META-INF",
+			path: "META-INF/LICENSE",
+			want: true,
+		},
+		{
+			name: "copyright at root",
+			path: "COPYRIGHT",
+			want: true,
+		},
+		{
+			name: "nested archive named license.jar",
+			path: "license.jar",
+			want: false,
+		},
+		{
+			name: "nested archive named copyright.war under META-INF",
+			path: "META-INF/copyright.war",
+			want: false,
+		},
+		{
+			name: "vendored license with prefix",
+			path: "META-INF/FastDoubleParser-LICENSE",
+			want: false,
+		},
+		{
+			name: "license in subdirectory",
+			path: "META-INF/licenses/LICENSE",
+			want: false,
+		},
+		{
+			name: "unrelated file",
+			path: "com/example/Main.class",
+			want: false,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			assert.Equal(t, tt.want, jar.IsJarLicenseFile(tt.path))
+		})
+	}
+}