feat: add luau qsv_writejson helper

src/cmd/luau.rs

@@ -1827,6 +1827,83 @@ fn setup_helpers(
         })?;
     luau.globals().set("qsv_loadjson", qsv_loadjson)?;
 
+    // this is a helper function to save a Luau table to a JSON file.
+    //
+    //   qsv_writejson(table_or_value: any, filepath: string, pretty: boolean)
+    //   table_or_value: the Luau table or value to save as JSON
+    //        filepath: the path of the JSON file to save
+    //          pretty: whether to format the JSON with indentation (optional, defaults to false)
+    //         returns: true if successful.
+    //                  A Luau runtime error if the filepath is invalid or JSON conversion fails.
+    //
+    let qsv_writejson = luau.create_function(
+        move |_, (table_or_value, filepath, pretty): (mlua::Value, String, Option<bool>)| {
+            use sanitize_filename::sanitize;
+
+            if filepath.is_empty() {
+                return helper_err!("qsv_writejson", "filepath cannot be empty.");
+            }
+
+            let sanitized_filename = sanitize(filepath);
+
+            // Convert Lua value to serde_json::Value using proper serialization
+            let json_value = if pretty.unwrap_or(false) {
+                match serde_json::to_string_pretty(&table_or_value) {
+                    Ok(v) => v,
+                    Err(e) => {
+                        return helper_err!(
+                            "qsv_writejson",
+                            "Failed to convert Luau value to JSON: {e}"
+                        );
+                    },
+                }
+            } else {
+                match serde_json::to_string(&table_or_value) {
+                    Ok(v) => v,
+                    Err(e) => {
+                        return helper_err!(
+                            "qsv_writejson",
+                            "Failed to convert Luau value to JSON: {e}"
+                        );
+                    },
+                }
+            };
+
+            // Create file
+            let file = match std::fs::OpenOptions::new()
+                .write(true)
+                .create(true)
+                .truncate(true)
+                .open(&sanitized_filename)
+            {
+                Ok(f) => f,
+                Err(e) => {
+                    return helper_err!(
+                        "qsv_writejson",
+                        "Failed to create JSON file \"{sanitized_filename}\": {e}"
+                    );
+                },
+            };
+            let mut file = std::io::BufWriter::with_capacity(DEFAULT_WTR_BUFFER_CAPACITY, file);
+
+            // Write JSON
+            if let Err(e) = file.write_all(json_value.as_bytes()) {
+                return helper_err!(
+                    "qsv_writejson",
+                    "Failed to write JSON to file \"{sanitized_filename}\": {e}"
+                );
+            }
+
+            info!(
+                "qsv_writejson() - saved {} bytes to file: {sanitized_filename}",
+                json_value.to_string().len()
+            );
+
+            Ok(true)
+        },
+    )?;
+    luau.globals().set("qsv_writejson", qsv_writejson)?;
+
     // this is a helper function that can be called from the BEGIN, MAIN & END scripts to write to
     // a file. The file will be created if it does not exist. The file will be appended to if it
     // already exists. The filename will be sanitized and will be written to the current working