feat: tps agent logs --follow race condition fix (ops-94) (#192)

* task complete: 39e2f6da-6003-43c2-ad43-3c246271d0a2

* boot

* task complete: 909a43d4-69df-4c28-9eab-f2934be5813e

Author: tps-ember

.tps-agent.pid

@@ -0,0 +1 @@
+58542

packages/cli/bin/tps.ts

@@ -309,7 +309,7 @@ async function main() {
           action: "logs",
           id: getFlag("id") ?? rest[1],
           lines: cli.flags.lines as number | undefined,
-          follow: cli.flags.follow as boolean | undefined,
+          follow: (cli.flags.follow as boolean | undefined) || process.argv.includes("-f"),
         });
       } else if (action === "commit") {
         // Inline helpers (getAuthor/getRepeatedFlags defined in else block below)

packages/cli/src/commands/agent.ts

@@ -110,14 +110,22 @@ function tailLines(content: string, count: number): string[] {
 
 async function streamLogUpdates(logPath: string, offset: number): Promise<never> {
   let position = offset;
+  let reading = false;
+  let pending = false;
 
   const readFromPosition = (): void => {
+    if (reading) {
+      pending = true;
+      return;
+    }
+
     const size = statSync(logPath).size;
     if (size < position) {
       position = 0;
     }
     if (size === position) return;
 
+    reading = true;
     const stream = createReadStream(logPath, {
       encoding: "utf-8",
       start: position,
@@ -130,17 +138,33 @@ async function streamLogUpdates(logPath: string, offset: number): Promise<never>
 
     stream.on("end", () => {
       position = size;
+      reading = false;
+      if (pending) {
+        pending = false;
+        readFromPosition();
+      }
     });
-  };
 
-  readFromPosition();
+    stream.on("error", () => {
+      reading = false;
+    });
+  };
 
-  await new Promise<never>((_resolve) => {
-    watch(logPath, { persistent: true }, (eventType) => {
+  await new Promise<never>(() => {
+    const watcher = watch(logPath, { persistent: true }, (eventType) => {
       if (eventType === "change" || eventType === "rename") {
         readFromPosition();
       }
     });
+
+    const handleSigint = (): void => {
+      watcher.close();
+      process.removeListener("SIGINT", handleSigint);
+      process.stdout.write("\n");
+      process.exit(0);
+    };
+
+    process.on("SIGINT", handleSigint);
   });
 
   process.exit(0);
@@ -149,12 +173,12 @@ async function streamLogUpdates(logPath: string, offset: number): Promise<never>
 async function logAgentRuntime(args: AgentArgs): Promise<void> {
   const agentId = args.id;
   if (!agentId) {
-    console.error("Usage: tps agent logs --id <agent-id> [--lines <N>] [--follow]");
+    console.error("Usage: tps agent logs --id <agent-id> [--lines <N>] [--follow|-f]");
     process.exit(1);
   }
 
   const lineCount = normalizeLogLineCount(args.lines);
-  const logPath = join(healthcheckHomeDir(), ".tps", "logs", `${agentId}.log`);
+  const logPath = join(healthcheckHomeDir(), ".tps", "agents", agentId, "session.log");
   if (!existsSync(logPath)) {
     console.error(`No log file found for ${agentId}`);
     process.exit(1);

packages/cli/test/agent-runtime-logs.test.ts

@@ -11,6 +11,12 @@ describe("tps agent logs runtime tail", () => {
   let originalError: typeof console.error;
   let originalExit: typeof process.exit;
 
+  function writeSessionLog(agentId: string, content: string): void {
+    const logDir = join(tempHome, ".tps", "agents", agentId);
+    mkdirSync(logDir, { recursive: true });
+    writeFileSync(join(logDir, "session.log"), content, "utf-8");
+  }
+
   beforeEach(() => {
     tempHome = mkdtempSync(join(tmpdir(), "tps-agent-runtime-logs-"));
     originalHome = process.env.HOME;
@@ -35,11 +41,9 @@ describe("tps agent logs runtime tail", () => {
   test("shows the last 50 lines by default", async () => {
     const { runAgent } = await import("../src/commands/agent.js");
     const output: string[] = [];
-    mkdirSync(join(tempHome, ".tps", "logs"), { recursive: true });
-    writeFileSync(
-      join(tempHome, ".tps", "logs", "ember.log"),
+    writeSessionLog(
+      "ember",
       Array.from({ length: 60 }, (_, index) => `line-${index + 1}`).join("\n") + "\n",
-      "utf-8",
     );
     process.stdout.write = ((chunk: string | Uint8Array) => {
       output.push(typeof chunk === "string" ? chunk : Buffer.from(chunk).toString("utf-8"));
@@ -56,11 +60,9 @@ describe("tps agent logs runtime tail", () => {
   test("respects a custom line count", async () => {
     const { runAgent } = await import("../src/commands/agent.js");
     const output: string[] = [];
-    mkdirSync(join(tempHome, ".tps", "logs"), { recursive: true });
-    writeFileSync(
-      join(tempHome, ".tps", "logs", "ember.log"),
+    writeSessionLog(
+      "ember",
       ["alpha", "beta", "gamma", "delta"].join("\n"),
-      "utf-8",
     );
     process.stdout.write = ((chunk: string | Uint8Array) => {
       output.push(typeof chunk === "string" ? chunk : Buffer.from(chunk).toString("utf-8"));