append newline to autocomplete input if it's missing

internal/complete/complete.go

@@ -139,6 +139,11 @@ func doComplete(compLine string, compWord string) {
 			return
 		}
 
+		// Append newline if it's missing. (https://github.com/antonmedv/fx/issues/303)
+		if input[len(input)-1] != '\n' {
+			input = append(input, '\n')
+		}
+
 		// If input is bigger than 100MB, skip completion.
 		if len(input) > 100*1024*1024 {
 			return