refactor cli

extensions/ql-vscode/src/codeql-cli/cli.ts

@@ -537,20 +537,6 @@ export class CodeQLCliServer implements Disposable {
   }
 }
 
-/**
- * Spawns a child server process using the CodeQL CLI
- * and attaches listeners to it.
- *
- * @param config The configuration containing the path to the CLI.
- * @param name Name of the server being started, to be shown in log and error messages.
- * @param command The `codeql` command to be run, provided as an array of command/subcommand names.
- * @param commandArgs The arguments to pass to the `codeql` command.
- * @param logger Logger to write startup messages.
- * @param stderrListener Listener for log messages from the server's stderr stream.
- * @param stdoutListener Optional listener for messages from the server's stdout stream.
- * @param progressReporter Used to output progress messages, e.g. to the status bar.
- * @returns The started child process.
- */
 export function spawnServer(
   codeqlPath: string,
   name: string,
@@ -561,52 +547,36 @@ export function spawnServer(
   stdoutListener?: (data: string | Buffer) => void,
   progressReporter?: ProgressReporter,
 ): ChildProcessWithoutNullStreams {
-  // Enable verbose logging.
-  const args = command.concat(commandArgs).concat(LOGGING_FLAGS);
+  const args = [...command, ...commandArgs, ...LOGGING_FLAGS];
+  progressReporter?.report({ message: `Starting ${name}` });
 
-  // Start the server process.
-  const base = codeqlPath;
-  const argsString = args.join(" ");
-  if (progressReporter !== undefined) {
-    progressReporter.report({ message: `Starting ${name}` });
-  }
-  void logger.log(`Starting ${name} using CodeQL CLI: ${base} ${argsString}`);
-  const child = spawnChildProcess(base, args);
-  if (!child || !child.pid) {
+  logger.log(
+    `Starting ${name} using CodeQL CLI: ${codeqlPath} ${args.join(" ")}`,
+  );
+  const child = spawnChildProcess(codeqlPath, args);
+
+  if (!child?.pid) {
     throw new Error(
-      `Failed to start ${name} using command ${base} ${argsString}.`,
+      `Failed to start ${name} using command ${codeqlPath} ${args.join(" ")}`,
     );
   }
 
-  let lastStdout: string | Buffer | undefined = undefined;
-  child.stdout!.on("data", (data) => {
-    lastStdout = data;
-  });
-  // Set up event listeners.
-  child.on("close", async (code, signal) => {
-    if (code !== null) {
-      void logger.log(`Child process exited with code ${code}`);
-    }
-    if (signal) {
-      void logger.log(
-        `Child process exited due to receipt of signal ${signal}`,
-      );
-    }
-    // If the process exited abnormally, log the last stdout message,
-    // It may be from the jvm.
-    if (code !== 0 && lastStdout !== undefined) {
-      void logger.log(`Last stdout was "${lastStdout.toString()}"`);
-    }
-  });
-  child.stderr!.on("data", stderrListener);
-  if (stdoutListener !== undefined) {
-    child.stdout!.on("data", stdoutListener);
-  }
+  let lastStdout: string | Buffer | undefined;
+  child.stdout!.on("data", (data) => (lastStdout = data));
+
+  child.on("close", (code, signal) => {
+    if (code !== null) logger.log(`Child process exited with code ${code}`);
+    if (signal) logger.log(`Child process exited due to signal ${signal}`);
+    if (code !== 0 && lastStdout)
+      logger.log(`Last stdout was "${lastStdout.toString()}"`);
+  });
+
+  child.stderr!.on("data", stderrListener);
+  stdoutListener && child.stdout!.on("data", stdoutListener);
+
+  progressReporter?.report({ message: `Started ${name}` });
+  logger.log(`${name} started on PID: ${child.pid}`);
 
-  if (progressReporter !== undefined) {
-    progressReporter.report({ message: `Started ${name}` });
-  }
-  void logger.log(`${name} started on PID: ${child.pid}`);
   return child;
 }