Improve mcp test coverage in workspace

Use the workspace-built MCP binary directly in tests and add focused helper coverage for argument parsing so regressions are caught without requiring a live server.

Co-Authored-By: HAL 9000

Author: tnull

ldk-server-mcp/src/tools/handlers.rs

@@ -842,3 +842,82 @@ pub async fn handle_graph_get_node(client: &LdkServerClient, args: Value) -> Res
 		.map_err(|e| e.message.clone())?;
 	serde_json::to_value(response).map_err(|e| format!("Failed to serialize response: {e}"))
 }
+
+#[cfg(test)]
+mod tests {
+	use super::{
+		build_bolt11_invoice_description, build_channel_config, build_update_channel_config,
+		parse_page_token,
+	};
+	use ldk_server_client::ldk_server_grpc::types::bolt11_invoice_description;
+	use serde_json::json;
+
+	#[test]
+	fn parse_page_token_rejects_invalid_formats() {
+		assert_eq!(
+			parse_page_token("missing-colon").unwrap_err(),
+			"Page token must be in format 'token:index'"
+		);
+		assert_eq!(parse_page_token("token:not-a-number").unwrap_err(), "Invalid page token index");
+	}
+
+	#[test]
+	fn build_bolt11_invoice_description_rejects_conflicting_fields() {
+		let err = build_bolt11_invoice_description(&json!({
+			"description": "desc",
+			"description_hash": "hash"
+		}))
+		.unwrap_err();
+
+		assert_eq!(err, "Only one of description or description_hash can be set");
+	}
+
+	#[test]
+	fn build_bolt11_invoice_description_supports_direct_and_hash_modes() {
+		let direct =
+			build_bolt11_invoice_description(&json!({ "description": "desc" })).unwrap().unwrap();
+		assert!(matches!(
+			direct.kind,
+			Some(bolt11_invoice_description::Kind::Direct(ref value)) if value == "desc"
+		));
+
+		let hash = build_bolt11_invoice_description(&json!({ "description_hash": "hash" }))
+			.unwrap()
+			.unwrap();
+		assert!(matches!(
+			hash.kind,
+			Some(bolt11_invoice_description::Kind::Hash(ref value)) if value == "hash"
+		));
+	}
+
+	#[test]
+	fn build_channel_config_rejects_conflicting_dust_exposure_modes() {
+		let err = build_channel_config(&json!({
+			"max_dust_htlc_exposure_fixed_limit_msat": 1,
+			"max_dust_htlc_exposure_fee_rate_multiplier": 2
+		}))
+		.unwrap_err();
+
+		assert_eq!(
+			err,
+			"Only one of max_dust_htlc_exposure_fixed_limit_msat or max_dust_htlc_exposure_fee_rate_multiplier can be set"
+		);
+	}
+
+	#[test]
+	fn build_channel_config_returns_none_when_no_fields_are_set() {
+		assert!(build_channel_config(&json!({})).unwrap().is_none());
+	}
+
+	#[test]
+	fn build_update_channel_config_defaults_to_empty_config() {
+		let channel_config = build_update_channel_config(&json!({})).unwrap();
+
+		assert_eq!(channel_config.forwarding_fee_proportional_millionths, None);
+		assert_eq!(channel_config.forwarding_fee_base_msat, None);
+		assert_eq!(channel_config.cltv_expiry_delta, None);
+		assert_eq!(channel_config.force_close_avoidance_max_fee_satoshis, None);
+		assert_eq!(channel_config.accept_underpaying_htlcs, None);
+		assert_eq!(channel_config.max_dust_htlc_exposure, None);
+	}
+}

ldk-server-mcp/tests/integration.rs

@@ -8,7 +8,6 @@
 // licenses.
 
 use std::io::{BufRead, BufReader, Write};
-use std::process::{Command, Stdio};
 
 use serde_json::{json, Value};
 
@@ -61,29 +60,6 @@ fn test_cert_path() -> String {
 		.to_string()
 }
 
-fn cargo_bin_path() -> String {
-	let output = Command::new("cargo")
-		.args(["build", "--message-format=json"])
-		.stderr(Stdio::piped())
-		.stdout(Stdio::piped())
-		.output()
-		.expect("Failed to build binary");
-
-	let stdout = String::from_utf8(output.stdout).unwrap();
-	for line in stdout.lines() {
-		if let Ok(msg) = serde_json::from_str::<Value>(line) {
-			if msg.get("reason").and_then(|r| r.as_str()) == Some("compiler-artifact")
-				&& msg.get("target").and_then(|t| t.get("name")).and_then(|n| n.as_str())
-					== Some("ldk-server-mcp")
-				&& msg.get("executable").and_then(|e| e.as_str()).is_some()
-			{
-				return msg["executable"].as_str().unwrap().to_string();
-			}
-		}
-	}
-	panic!("Could not find compiled binary path");
-}
-
 struct McpProcess {
 	child: std::process::Child,
 	stdin: std::process::ChildStdin,
@@ -92,14 +68,13 @@ struct McpProcess {
 
 impl McpProcess {
 	fn spawn() -> Self {
-		let bin = cargo_bin_path();
-		let mut child = Command::new(&bin)
+		let mut child = std::process::Command::new(env!("CARGO_BIN_EXE_ldk-server-mcp"))
 			.env("LDK_BASE_URL", "localhost:19999")
 			.env("LDK_API_KEY", "deadbeef")
 			.env("LDK_TLS_CERT_PATH", test_cert_path())
-			.stdin(Stdio::piped())
-			.stdout(Stdio::piped())
-			.stderr(Stdio::piped())
+			.stdin(std::process::Stdio::piped())
+			.stdout(std::process::Stdio::piped())
+			.stderr(std::process::Stdio::piped())
 			.spawn()
 			.expect("Failed to spawn MCP process");