Discover: Always return a possible directory.

Discover is used by the language server to find the root of a project.
If the root is not found, it will now return the initial directory.

Closes #709

project/project.go

@@ -268,7 +268,7 @@ func Discover(path string) []Suite {
 		}
 		list = append(list, readIndices(fs.JoinPath(path, IndexFile))...)
 
-		// Check build directories
+		// Check parallel build directories
 		for _, file := range fs.Glob(path + "/*build*/" + IndexFile) {
 			list = append(list, readIndices(file)...)
 		}
@@ -290,6 +290,12 @@ func Discover(path string) []Suite {
 		})
 	}
 
+	// If we still could not find any coherent test suite, just add the
+	// current directory in the hopes it contains TTCN-3 files.
+	if len(list) == 0 {
+		return []Suite{{RootDir: path, SourceDir: path}}
+	}
+
 	// Remove duplicate entries
 	result := make([]Suite, 0, len(list))
 	visited := make(map[Suite]bool)