Function validate_fragment_source 

fn validate_fragment_source(
    config_json: &str,
    source_string: &str,
) -> (Vec<String>, String)

Validates a fragment source XPath expression and computes dependencies

Parses the source string to find all ./FRAGMENT[…] references, validates that referenced fragments exist, and returns their IDs.

Arguments

• config_json - Configuration JSON string
• source_string - Fragment source XPath expression

Returns

Returns (dependency_ids, error_message) tuple

• dependency_ids: Vec of fragment IDs as strings (empty if no dependencies)
• error_message: Empty string on success, error description on failure

Example

use sz_configtool_lib::fragments;
let source = "./FRAGMENT[./SAME_NAME>0 and ./SAME_STAB>0]";
let config = r#"{"G2_CONFIG": {"CFG_ERFRAG": []}}"#;
// Note: validate_fragment_source is private, used internally by add_fragment