Improve execution preflight diagnostics

web/tests/unit/generated-gap-preflight.test.mjs

@@ -0,0 +1,28 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+import { collectGeneratedGapPreflight } from "../../../tools/web/generated-gap-preflight.mjs";
+import { readIndexedTask, root, verifyTaskIndex } from "../../../tools/web/task-context-lib.mjs";
+
+test("generated gap preflight accepts a runnable task with existing inputs", () => {
+  verifyTaskIndex();
+  const entry = readIndexedTask("M16-GAP-00281");
+  assert.deepEqual(collectGeneratedGapPreflight({ root, task: "M16-GAP-00281", entry }), []);
+});
+
+test("generated gap preflight reports state and input failures before WASM startup", () => {
+  const issues = collectGeneratedGapPreflight({
+    root,
+    task: "M16-GAP-00282",
+    entry: {
+      id: "M16-GAP-00282",
+      state: "pending",
+      fixture: { path: "tests/files/web/generated/does-not-exist.blend" },
+      desktopCommand: "blender --python tools/web/generated/does-not-exist.py -- fixture.blend",
+    },
+  });
+  assert.deepEqual(issues.map(({ code }) => code), ["TASK_NOT_RUNNABLE", "INPUT_MISSING", "INPUT_MISSING"]);
+});
+
+test("generated gap preflight rejects a missing task argument", () => {
+  assert.deepEqual(collectGeneratedGapPreflight({ root, task: undefined, entry: null }).map(({ code }) => code), ["TASK_ARGUMENT_INVALID"]);
+});