schema: export union for single/parallel modes; require single preset/task; expose single-model; update tests

src/extension.test.ts

@@ -36,17 +36,24 @@ test("the extension entrypoint registers the subagent tool with the currently av
 
     assert.equal(registeredTools.length, 1);
     assert.equal(registeredTools[0]?.name, "subagent");
-    // no single top-level model required now (handled at runtime)
-    assert.equal("agent" in registeredTools[0]?.parameters.properties, false);
-    assert.equal("agentScope" in registeredTools[0]?.parameters.properties, false);
-    assert.equal("confirmProjectAgents" in registeredTools[0]?.parameters.properties, false);
-    assert.equal("task" in registeredTools[0]?.parameters.properties, true);
-    assert.equal("preset" in registeredTools[0]?.parameters.properties, true);
-    assert.equal(registeredTools[0]?.parameters.properties.model, undefined);
-    assert.equal("agent" in registeredTools[0]?.parameters.properties.tasks.items.properties, false);
-    assert.equal("task" in registeredTools[0]?.parameters.properties.tasks.items.properties, true);
-    assert.equal("preset" in registeredTools[0]?.parameters.properties.tasks.items.properties, true);
-    assert.deepEqual(registeredTools[0]?.parameters.properties.tasks.items.properties.model.enum, [
+    const params = registeredTools[0]?.parameters;
+    const branches = params?.anyOf ?? params?.oneOf ?? [params];
+    // ensure union branches exist: single-mode and parallel-mode
+    assert(branches && branches.length === 2);
+    // no agent/agentScope/confirmProjectAgents in any branch
+    for (const key of ["agent", "agentScope", "confirmProjectAgents"]) {
+      assert.equal(branches.some((b: any) => b.properties && key in b.properties), false);
+    }
+    const singleBranch = branches.find((b: any) => b.properties && "task" in b.properties && "preset" in b.properties);
+    assert(singleBranch, "single-mode branch present");
+    // single branch exposes optional top-level model
+    assert.equal("model" in singleBranch.properties, true);
+    const parallelBranch = branches.find((b: any) => b.properties && "tasks" in b.properties);
+    assert(parallelBranch, "parallel-mode branch present");
+    assert.equal("agent" in parallelBranch.properties.tasks.items.properties, false);
+    assert.equal("task" in parallelBranch.properties.tasks.items.properties, true);
+    assert.equal("preset" in parallelBranch.properties.tasks.items.properties, true);
+    assert.deepEqual(parallelBranch.properties.tasks.items.properties.model.enum, [
       "anthropic/claude-sonnet-4-5",
       "openai/gpt-5",
     ]);
@@ -91,10 +98,16 @@ test("before_agent_start re-applies subagent registration when available models
     );
 
     assert.equal(registeredTools.length, 1);
-    assert.deepEqual(registeredTools[0]?.parameters.properties.tasks.items.properties.model.enum, [
+    {
+      const params = registeredTools[0]?.parameters;
+      const branches = params?.anyOf ?? params?.oneOf ?? [params];
+      const parallelBranch = branches.find((b: any) => b.properties && "tasks" in b.properties);
+      assert(parallelBranch, "parallel branch present");
+      assert.deepEqual(parallelBranch.properties.tasks.items.properties.model.enum, [
         "anthropic/claude-sonnet-4-5",
         "openai/gpt-5",
       ]);
+    }
 
     // then before agent start with a different model set — should re-register
     await handlers.before_agent_start?.(
@@ -109,7 +122,13 @@ test("before_agent_start re-applies subagent registration when available models
     );
 
     assert.equal(registeredTools.length, 2);
-    assert.deepEqual(registeredTools[1]?.parameters.properties.tasks.items.properties.model.enum, ["openai/gpt-6"]);
+    {
+      const params = registeredTools[1]?.parameters;
+      const branches = params?.anyOf ?? params?.oneOf ?? [params];
+      const parallelBranch = branches.find((b: any) => b.properties && "tasks" in b.properties);
+      assert(parallelBranch, "parallel branch present");
+      assert.deepEqual(parallelBranch.properties.tasks.items.properties.model.enum, ["openai/gpt-6"]);
+    }
   } finally {
     if (original === undefined) delete process.env.PI_SUBAGENTS_CHILD;
     else process.env.PI_SUBAGENTS_CHILD = original;

src/schema.ts

@@ -21,15 +21,20 @@ export function createTaskItemSchema(availableModels: readonly string[]) {
 export const TaskItemSchema = createTaskItemSchema([]);
 
 export function createSubagentParamsSchema(availableModels: readonly string[]) {
-  return Type.Object({
-    // Single mode: provide preset + task
-    preset: Type.Optional(Type.String({ description: "Subagent preset name to use in single mode" })),
-    task: Type.Optional(Type.String({ description: "Single-mode delegated task" })),
-    // Parallel mode: provide tasks array where each item names its own preset
-    tasks: Type.Optional(Type.Array(createTaskItemSchema(availableModels), { description: "Parallel tasks" })),
+  // Single-mode schema: requires preset + task, exposes optional top-level model
+  const SingleMode = Type.Object({
+    preset: Type.String({ description: "Subagent preset name to use in single mode" }),
+    task: Type.String({ description: "Single-mode delegated task" }),
+    model: createTaskModelSchema(availableModels),
     cwd: Type.Optional(Type.String({ description: "Single-mode working directory override" })),
-
   });
+
+  // Parallel-mode schema: requires tasks array where each item contains its own preset and task
+  const ParallelMode = Type.Object({
+    tasks: Type.Array(createTaskItemSchema(availableModels), { description: "Parallel tasks" }),
+  });
+
+  return Type.Union([SingleMode, ParallelMode], { description: "Either single-mode (preset+task) or parallel-mode (tasks array)" });
 }
 
 export const SubagentParamsSchema = createSubagentParamsSchema([]);