From 7184008b3205ea6b177151d9c8ca8b35c84d2f88 Mon Sep 17 00:00:00 2001
From: Lior <lior@zeta.dev>
Date: Thu, 28 May 2026 04:55:10 -0400
Subject: [PATCH] fix(B-0891): fix-fwd 4 tsc errors in zflash test-harness PoC
 (exactOptionalPropertyTypes + noUncheckedIndexedAccess)
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PR #5724 (zflash test-harness PoC) race-merged through with non-required
lint(tsc tools) failure per blocked-green-ci-investigate-threads.md
auto-merge-race-with-follow-up-commit anti-pattern. Fix-fwd lands the
tsc-clean substrate.

4 errors fixed:

1. run.ts:88 / 95 — array-index returns string | undefined under
   noUncheckedIndexedAccess; reify positional[0] into typed local + check
   undefined explicitly before returning ParsedArgs
2. run.ts:174 — message: undefined fails exactOptionalPropertyTypes;
   refactored to conditional return that omits message field when not set
3. scenarios.test.ts:68 — { ...SCENARIOS[0] } widens because SCENARIOS[0]
   is Scenario | undefined; reify first into typed local + assert before
   spread

Gate verification:
- bunx tsc --noEmit (tools/zflash) → 0 errors
- bun test tools/zflash/test-harness/ → 12 pass / 0 fail / 26 expect

Substrate-honest framing: race-merged content stays on main as substrate;
fix-fwd lands the correction per substrate-honest discipline per
auto-merge-race documentation in blocked-green-ci-investigate-threads.md.

Composes with: PR #5724 (B-0891 PoC); blocked-green-ci-investigate-threads
rule (Auto-merge-race-with-follow-up-commit anti-pattern); zeta-expected-
branch.md race-window-caveat (isolated worktree workflow).

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
---
 tools/zflash/test-harness/run.ts            | 25 ++++++++++++---------
 tools/zflash/test-harness/scenarios.test.ts |  4 +++-
 2 files changed, 18 insertions(+), 11 deletions(-)

diff --git a/tools/zflash/test-harness/run.ts b/tools/zflash/test-harness/run.ts
index e090a63526..4299f1f1ec 100644
--- a/tools/zflash/test-harness/run.ts
+++ b/tools/zflash/test-harness/run.ts
@@ -82,17 +82,19 @@ function parseArgs(argv: ReadonlyArray<string>): ParsedArgs | { error: string }
     }
     const id = args[scenarioIdx + 1] as ScenarioId;
     const positional = args.filter((a, i) => i !== scenarioIdx && i !== scenarioIdx + 1 && !a.startsWith("--"));
-    if (positional.length === 0) {
+    const isoPath = positional[0];
+    if (positional.length === 0 || isoPath === undefined) {
       return { error: "--scenario requires an ISO path positional argument" };
     }
-    return { mode: "scenario", scenarioId: id, isoPath: positional[0] };
+    return { mode: "scenario", scenarioId: id, isoPath };
   }
   if (args.includes("--all")) {
     const positional = args.filter((a) => !a.startsWith("--"));
-    if (positional.length === 0) {
+    const isoPath = positional[0];
+    if (positional.length === 0 || isoPath === undefined) {
       return { error: "--all requires an ISO path positional argument" };
     }
-    return { mode: "all", isoPath: positional[0] };
+    return { mode: "all", isoPath };
   }
   return { error: `unrecognized arguments: ${args.join(" ")}` };
 }
@@ -171,12 +173,15 @@ function runComposingScenario(scenario: Scenario, isoPath: string): ScenarioResu
     stdio: "inherit",
   });
   const durationMs = Date.now() - start;
-  return {
-    id: scenario.id,
-    status: result.status === 0 ? "passed" : "failed",
-    durationMs,
-    message: result.status === 0 ? undefined : `delegated harness exited ${result.status}`,
-  };
+  const passed = result.status === 0;
+  return passed
+    ? { id: scenario.id, status: "passed", durationMs }
+    : {
+        id: scenario.id,
+        status: "failed",
+        durationMs,
+        message: `delegated harness exited ${result.status}`,
+      };
 }
 
 function reportScaffolded(scenario: Scenario): ScenarioResult {
diff --git a/tools/zflash/test-harness/scenarios.test.ts b/tools/zflash/test-harness/scenarios.test.ts
index ce4fb89d09..3396b3a643 100644
--- a/tools/zflash/test-harness/scenarios.test.ts
+++ b/tools/zflash/test-harness/scenarios.test.ts
@@ -65,7 +65,9 @@ describe("B-0891 scenarios.ts invariants", () => {
   });
 
   it("validateScenarios catches duplicate id", () => {
-    const dup = [...SCENARIOS, { ...SCENARIOS[0] }];
+    const first = SCENARIOS[0];
+    if (!first) throw new Error("SCENARIOS unexpectedly empty");
+    const dup = [...SCENARIOS, { ...first }];
     expect(() => validateScenarios(dup)).toThrow();
   });