feat: stabilize process output scope

src/process-output-scope.test.ts

@@ -0,0 +1,45 @@
+import { describe, expect, test } from "bun:test";
+import { aggregateProcessOutput, formatProcessOutputTitle } from "./process-output-scope";
+
+describe("aggregateProcessOutput", () => {
+  test("sorts by timestamp and uses source order as a tie-breaker", () => {
+    expect(
+      aggregateProcessOutput([
+        {
+          name: "api",
+          entries: [
+            { timestamp: "2026-06-09T00:00:02.000Z", stream: "stdout", line: "second" },
+            { timestamp: "2026-06-09T00:00:01.000Z", stream: "stdout", line: "api first" },
+          ],
+        },
+        {
+          name: "worker",
+          entries: [
+            { timestamp: "2026-06-09T00:00:01.000Z", stream: "stderr", line: "worker first" },
+          ],
+        },
+      ]).map((entry) => entry.line),
+    ).toEqual(["[api] api first", "[worker] worker first", "[api] second"]);
+  });
+
+  test("preserves per-source order for identical timestamps", () => {
+    expect(
+      aggregateProcessOutput([
+        {
+          name: "api",
+          entries: [
+            { timestamp: "2026-06-09T00:00:01.000Z", stream: "stdout", line: "one" },
+            { timestamp: "2026-06-09T00:00:01.000Z", stream: "stdout", line: "two" },
+          ],
+        },
+      ]).map((entry) => entry.line),
+    ).toEqual(["[api] one", "[api] two"]);
+  });
+});
+
+describe("formatProcessOutputTitle", () => {
+  test("formats aggregate and scoped titles", () => {
+    expect(formatProcessOutputTitle(null)).toBe("Logs");
+    expect(formatProcessOutputTitle("api")).toBe("Logs (api)");
+  });
+});

src/process-output-scope.ts

@@ -0,0 +1,29 @@
+import type { LogEntry } from "./types";
+
+export interface ProcessOutputSource {
+  name: string;
+  entries: LogEntry[];
+}
+
+export const aggregateProcessOutput = (sources: ProcessOutputSource[]): LogEntry[] =>
+  sources
+    .flatMap((source, sourceIndex) =>
+      source.entries.map((entry, entryIndex) => ({
+        entry: {
+          ...entry,
+          line: `[${source.name}] ${entry.line}`,
+        },
+        sourceIndex,
+        entryIndex,
+      })),
+    )
+    .sort((left, right) => {
+      const timestampOrder = left.entry.timestamp.localeCompare(right.entry.timestamp);
+      if (timestampOrder !== 0) return timestampOrder;
+      if (left.sourceIndex !== right.sourceIndex) return left.sourceIndex - right.sourceIndex;
+      return left.entryIndex - right.entryIndex;
+    })
+    .map((item) => item.entry);
+
+export const formatProcessOutputTitle = (name: string | null): string =>
+  name ? `Logs (${name})` : "Logs";

src/ui.ts

@@ -19,6 +19,7 @@ import {
   formatDuration,
   type ProcessMetricsSample,
 } from "./process-metrics";
+import { aggregateProcessOutput, formatProcessOutputTitle } from "./process-output-scope";
 import { getRuntimeStatusView } from "./runtime-status";
 import type { ServiceManager, ServiceView } from "./service-manager";
 import { formatCommandSpec } from "./shared";
@@ -1500,15 +1501,9 @@ export const buildUi = (opts: UiOptions): { teardown: () => void; controls: UiCo
       };
     }
 
-    const entries = manager
-      .getViews()
-      .flatMap((view) =>
-        view.log.all().map((entry) => ({
-          ...entry,
-          line: `[${view.name}] ${entry.line}`,
-        })),
-      )
-      .sort((a, b) => a.timestamp.localeCompare(b.timestamp));
+    const entries = aggregateProcessOutput(
+      manager.getViews().map((view) => ({ name: view.name, entries: view.log.all() })),
+    );
 
     return {
       entries,
@@ -2081,7 +2076,7 @@ export const buildUi = (opts: UiOptions): { teardown: () => void; controls: UiCo
       logSource === "external" && externalRuntimeManager
         ? externalRuntimeManager.getSelectedService()?.name
         : manager.getSelectedView()?.name;
-    logPanelTitle.content = selectedLogName ? `Logs (${selectedLogName})` : "Logs";
+    logPanelTitle.content = formatProcessOutputTitle(selectedLogName ?? null);
     logPanelTitle.fg = panelTitleColor("logs");
     const logsBackground = panelBackgroundColor("logs");
     servicePanel.backgroundColor = logsBackground;