Consider 'src/test' test directories

The Maven 'Standard Directory Layout' [0] is fairly widely used, not only
in Maven but also in adjacent ecosystems like Gradle and clojure.

Longer-term this would become part of the default policy, see discussion
at ossf#1408 (comment) etc.

[0]: https://maven.apache.org/guides/introduction/introduction-to-the-standard-directory-layout.html

checks/fileparser/listing.go

@@ -52,7 +52,9 @@ func isMatchingPath(fullpath string, matchPathTo PathMatcher) (bool, error) {
 func isTestdataFile(fullpath string) bool {
 	// testdata/ or /some/dir/testdata/some/other
 	return strings.HasPrefix(fullpath, "testdata/") ||
-		strings.Contains(fullpath, "/testdata/")
+		strings.Contains(fullpath, "/testdata/") ||
+		strings.HasPrefix(fullpath, "src/test/") ||
+		strings.Contains(fullpath, "/src/test/")
 }
 
 // PathMatcher represents a query for a filepath.

checks/fileparser/listing_test.go

@@ -375,6 +375,13 @@ func Test_isTestdataFile(t *testing.T) {
 			},
 			want: true,
 		},
+		{
+			name: "testdata file",
+			args: args{
+				fullpath: "archiva-modules/archiva-base/archiva-checksum/src/test/resources/examples/redback-authz-open.jar",
+			},
+			want: true,
+		},
 	}
 	for _, tt := range tests {
 		tt := tt // Re-initializing variable so it is not changed while executing the closure below