Feature/config validation

README.md

@@ -227,7 +227,7 @@ The roadmap for TextBlaster is divided into 6 phases, with subtasks to complete.
 3.  **Standardized Logging and Tracing:** Fully integrate the `tracing` crate, replacing all `println!` calls. Structure logs as JSON and add `doc_id` to tracing spans to correlate all messages for a specific document. Allow log level configuration via CLI.
 4.  **Refined Error Handling & Messaging:** Improve the clarity of all user-facing error messages. Ensure that when a task fails in a worker, the propagated error clearly identifies the worker ID, the failing step, and the root cause.
 5.  **Comprehensive Documentation:** Create a `docs/` folder with Markdown guides on architecture, configuration, and tutorials. Add `CONTRIBUTING.md` for new developers and ensure all public functions and structs have detailed doc comments (`///`).
-6.  **Configuration Validation:** Implement a `--validate-config` flag and an automatic startup check to validate the `pipeline_config.yaml`. This check will catch syntax errors, schema violations, and logical issues (e.g., a filter running before its dependency).
+6.  **Configuration Validation:** Implement a `--validate-config` flag and an automatic startup check to validate the `pipeline_config.yaml`. This check will catch syntax errors, schema violations, and logical issues (e.g., a filter running before its dependency). - *Done*
 
 ### **Phase 2: Core Pipeline Enhancement & Usability**
 **Theme:** Improve the user experience and expand the core capabilities of the processing pipeline, making it more flexible and powerful for common tasks.

src/bin/worker.rs

@@ -72,6 +72,10 @@ struct Args {
     /// Optional: Port for the Prometheus metrics HTTP endpoint
     #[arg(long)]
     metrics_port: Option<u16>,
+
+    /// Validate the pipeline configuration and exit
+    #[arg(long)]
+    validate_config: bool,
 }
 
 // --- Prometheus Metrics (now imported from TextBlaster::utils::prometheus_metrics) ---
@@ -377,6 +381,30 @@ async fn process_tasks(
 async fn main() -> Result<()> {
     let args = Args::parse();
 
+    if args.validate_config {
+        match load_pipeline_config(&args.pipeline_config) {
+            Ok(_) => {
+                // Note: Tracing might not be initialized here.
+                // Consider simple println for this specific validation output.
+                println!(
+                    "Configuration '{}' is valid.",
+                    args.pipeline_config.display()
+                );
+                std::process::exit(0);
+            }
+            Err(e) => {
+                // Note: Tracing might not be initialized here.
+                // Consider simple eprintln for this specific validation output.
+                eprintln!(
+                    "Configuration '{}' is invalid: {}",
+                    args.pipeline_config.display(),
+                    e
+                );
+                std::process::exit(1);
+            }
+        }
+    }
+
     // Initialize tracing subscriber
     let env_filter = EnvFilter::try_from_default_env().unwrap_or_else(|_| EnvFilter::new("info")); // Default to info if RUST_LOG is not set