fix(runtime): classify run usage status

tests/unit/run-usage-status.test.ts

@@ -0,0 +1,84 @@
+import { describe, expect, it } from "vitest";
+import {
+  classifyRunUsage,
+  deriveLegacyRunUsageStatus,
+  hasAttributableAssistantUsage,
+} from "../../src/main/run-usage-status";
+
+describe("run usage status", () => {
+  it("does not treat pi error EMPTY_USAGE as attributable cost", () => {
+    expect(
+      hasAttributableAssistantUsage({
+        role: "assistant",
+        stopReason: "error",
+        usage: { input: 0, output: 0 },
+      }),
+    ).toBe(false);
+  });
+
+  it("accepts normal assistant usage as attributable", () => {
+    expect(
+      hasAttributableAssistantUsage({
+        role: "assistant",
+        stopReason: "stop",
+        usage: { input: 12, output: 7 },
+      }),
+    ).toBe(true);
+  });
+
+  it("keeps non-zero terminal usage attributable", () => {
+    expect(
+      hasAttributableAssistantUsage({
+        role: "assistant",
+        stopReason: "error",
+        usage: { input: 12, output: 1 },
+      }),
+    ).toBe(true);
+  });
+
+  it("classifies terminal usage states explicitly", () => {
+    expect(
+      classifyRunUsage({
+        runStatus: "failed",
+        errorMessage: "stream setup failed",
+        sawAttributableUsage: false,
+        terminalStopReason: "error",
+      }),
+    ).toBe("error_stop");
+
+    expect(
+      classifyRunUsage({
+        runStatus: "cancelled",
+        errorMessage: null,
+        sawAttributableUsage: false,
+        terminalStopReason: "aborted",
+      }),
+    ).toBe("aborted_before_usage");
+
+    expect(
+      classifyRunUsage({
+        runStatus: "failed",
+        errorMessage: "prepareRun failed",
+        sawAttributableUsage: false,
+        terminalStopReason: null,
+      }),
+    ).toBe("pre_first_message");
+
+    expect(
+      classifyRunUsage({
+        runStatus: "succeeded",
+        errorMessage: null,
+        sawAttributableUsage: true,
+        terminalStopReason: null,
+      }),
+    ).toBe("ok");
+  });
+
+  it("maps legacy finishRun inputs into explicit usage status", () => {
+    expect(deriveLegacyRunUsageStatus({ runStatus: "succeeded", unattributedCost: false })).toBe("ok");
+    expect(deriveLegacyRunUsageStatus({ runStatus: "interrupted", unattributedCost: true })).toBe(
+      "aborted_before_usage",
+    );
+    expect(deriveLegacyRunUsageStatus({ runStatus: "failed", unattributedCost: true })).toBe("pre_first_message");
+  });
+});