Tests: add channel plugin contract helper

src/test-utils/channel-plugin-contract.ts

@@ -0,0 +1,24 @@
+import { expect, it } from "vitest";
+import type { ChannelPlugin } from "../channels/plugins/types.js";
+
+export function installChannelPluginContractSuite(params: {
+  plugin: Pick<ChannelPlugin, "id" | "meta" | "capabilities" | "config">;
+}) {
+  it("satisfies the base channel plugin contract", () => {
+    const { plugin } = params;
+
+    expect(typeof plugin.id).toBe("string");
+    expect(plugin.id.trim()).not.toBe("");
+
+    expect(plugin.meta.id).toBe(plugin.id);
+    expect(plugin.meta.label.trim()).not.toBe("");
+    expect(plugin.meta.selectionLabel.trim()).not.toBe("");
+    expect(plugin.meta.docsPath).toMatch(/^\/channels\//);
+    expect(plugin.meta.blurb.trim()).not.toBe("");
+
+    expect(plugin.capabilities.chatTypes.length).toBeGreaterThan(0);
+
+    expect(typeof plugin.config.listAccountIds).toBe("function");
+    expect(typeof plugin.config.resolveAccount).toBe("function");
+  });
+}