1 files changed, 161 insertions, 0 deletions
diff --git a/src/features/surface-host/logic/plan.test.ts b/src/features/surface-host/logic/plan.test.ts
new file mode 100644
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--- /dev/null
+++ b/src/features/surface-host/logic/plan.test.ts
@@ -0,0 +1,161 @@
+import type { SurfaceField, SurfaceSpec } from "@dispatch/ui-contract";
+import { describe, expect, it } from "vitest";
+import { buildInvoke, planSurface } from "./plan";
+
+const makeSpec = (...fields: SurfaceField[]): SurfaceSpec => ({
+	id: "test-surface",
+	region: "test",
+	title: "Test Surface",
+	fields,
+});
+
+describe("planSurface", () => {
+	it("maps a toggle field to a ToggleFieldView", () => {
+		const plan = planSurface(
+			makeSpec({ kind: "toggle", label: "Dark mode", value: true, action: { actionId: "dm" } }),
+		);
+		expect(plan.fields).toEqual([
+			{ kind: "toggle", label: "Dark mode", value: true, action: { actionId: "dm" } },
+		]);
+	});
+
+	it("maps a progress field to a ProgressFieldView", () => {
+		const plan = planSurface(makeSpec({ kind: "progress", label: "Loading", value: 0.42 }));
+		expect(plan.fields).toEqual([{ kind: "progress", label: "Loading", value: 0.42 }]);
+	});
+
+	it("maps a selector field to a SelectorFieldView", () => {
+		const plan = planSurface(
+			makeSpec({
+				kind: "selector",
+				label: "Model",
+				value: "gpt-4",
+				options: [
+					{ value: "gpt-4", label: "GPT-4" },
+					{ value: "gpt-3.5", label: "GPT-3.5" },
+				],
+				action: { actionId: "set-model" },
+			}),
+		);
+		expect(plan.fields).toEqual([
+			{
+				kind: "selector",
+				label: "Model",
+				value: "gpt-4",
+				options: [
+					{ value: "gpt-4", label: "GPT-4" },
+					{ value: "gpt-3.5", label: "GPT-3.5" },
+				],
+				action: { actionId: "set-model" },
+			},
+		]);
+	});
+
+	it("maps a stat field to a StatFieldView", () => {
+		const plan = planSurface(makeSpec({ kind: "stat", label: "Tokens", value: "1,234" }));
+		expect(plan.fields).toEqual([{ kind: "stat", label: "Tokens", value: "1,234" }]);
+	});
+
+	it("maps a button field to a ButtonFieldView", () => {
+		const plan = planSurface(
+			makeSpec({ kind: "button", label: "Retry", action: { actionId: "retry" } }),
+		);
+		expect(plan.fields).toEqual([
+			{ kind: "button", label: "Retry", action: { actionId: "retry" } },
+		]);
+	});
+
+	it("preserves field order", () => {
+		const plan = planSurface(
+			makeSpec(
+				{ kind: "stat", label: "A", value: "1" },
+				{ kind: "toggle", label: "B", value: false, action: { actionId: "b" } },
+				{ kind: "progress", label: "C", value: 0.5 },
+				{ kind: "button", label: "D", action: { actionId: "d" } },
+			),
+		);
+		expect(plan.fields.map((f) => f.label)).toEqual(["A", "B", "C", "D"]);
+	});
+
+	it("drops unknown field kinds gracefully", () => {
+		const plan = planSurface(
+			makeSpec({ kind: "stat", label: "Known", value: "ok" }, {
+				kind: "future-kind" as "stat",
+				label: "Unknown",
+				value: "?",
+			} as SurfaceField),
+		);
+		expect(plan.fields).toHaveLength(1);
+		expect(plan.fields[0]?.label).toBe("Known");
+	});
+
+	it("drops custom fields (no renderer registered)", () => {
+		const plan = planSurface(
+			makeSpec(
+				{ kind: "stat", label: "Before", value: "1" },
+				{ kind: "custom", rendererId: "chart", payload: { data: [1, 2, 3] } },
+				{ kind: "stat", label: "After", value: "2" },
+			),
+		);
+		expect(plan.fields).toHaveLength(2);
+		expect(plan.fields.map((f) => f.label)).toEqual(["Before", "After"]);
+	});
+
+	it("returns empty fields for an empty spec", () => {
+		const plan = planSurface(makeSpec());
+		expect(plan.fields).toEqual([]);
+	});
+
+	it("drops all fields when all are custom", () => {
+		const plan = planSurface(
+			makeSpec(
+				{ kind: "custom", rendererId: "x", payload: null },
+				{ kind: "custom", rendererId: "y", payload: 42 },
+			),
+		);
+		expect(plan.fields).toEqual([]);
+	});
+});
+
+describe("buildInvoke", () => {
+	it("builds an invoke message for a toggle field", () => {
+		const field = { kind: "toggle" as const, label: "T", value: false, action: { actionId: "t" } };
+		const msg = buildInvoke("s1", field, true);
+		expect(msg).toEqual({ type: "invoke", surfaceId: "s1", actionId: "t", payload: true });
+	});
+
+	it("builds an invoke message for a selector field", () => {
+		const field = {
+			kind: "selector" as const,
+			label: "S",
+			value: "a",
+			options: [],
+			action: { actionId: "sel" },
+		};
+		const msg = buildInvoke("s1", field, "b");
+		expect(msg).toEqual({ type: "invoke", surfaceId: "s1", actionId: "sel", payload: "b" });
+	});
+
+	it("builds an invoke message without payload for a button field", () => {
+		const field = { kind: "button" as const, label: "B", action: { actionId: "btn" } };
+		const msg = buildInvoke("s1", field);
+		expect(msg).toEqual({ type: "invoke", surfaceId: "s1", actionId: "btn" });
+	});
+
+	it("omits payload key when value is undefined", () => {
+		const field = { kind: "button" as const, label: "B", action: { actionId: "btn" } };
+		const msg = buildInvoke("s1", field, undefined);
+		expect(msg).not.toHaveProperty("payload");
+	});
+
+	it("uses the field's actionId, not a surface-level id", () => {
+		const field = {
+			kind: "toggle" as const,
+			label: "X",
+			value: true,
+			action: { actionId: "custom-action-123" },
+		};
+		const msg = buildInvoke("surf", field, false);
+		expect(msg.actionId).toBe("custom-action-123");
+	});
+});