test(coverage): bootstrap vitest unit infra and add tests at 90%+ per file (#1245) (#1269)

* test(coverage): bootstrap vitest unit infra and add tests at 90%+ per file (#1245)

Establishes the unit-test runtime AGENTS.md mandates: a vitest "unit"
project alongside the existing storybook project, RTL + jest-dom +
happy-dom, a Mantine-aware render helper, and a 90%-line per-file
coverage gate enforced by CI. Adds 66 test files covering all 62
components under elements/groups/screens/views, plus core/mcp and
clients/web/src/utils. Total: 577 tests, 98.7% line coverage globally.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* test(coverage): address PR #1269 review feedback

- AGENTS.md: correct coverage gate description (lines ≥ 90, statements ≥ 85,
  functions ≥ 80, branches ≥ 50) with rationale for the relaxed branch
  threshold
- InspectorView.test.tsx: document what the Math.random() mock values
  (0.1 / 0.99) control vs. STUB_SUCCESS_RATE in InspectorView.tsx
- vite.config.ts / tsconfig.test.json: drop unused `globals: true` and the
  `vitest/globals` type now that every test file imports describe/it/expect/vi
  explicitly; manual `afterEach(cleanup)` in setup.ts remains required because
  testing-library auto-cleanup relies on globalThis.afterEach

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

clients/web/src/components/groups/LogStreamPanel/LogStreamPanel.test.tsx

@@ -0,0 +1,175 @@
+import { describe, it, expect, vi } from "vitest";
+import userEvent from "@testing-library/user-event";
+import type { LoggingLevel } from "@modelcontextprotocol/sdk/types.js";
+import { renderWithMantine, screen } from "../../../test/renderWithMantine";
+import { LogStreamPanel } from "./LogStreamPanel";
+import type { LogEntryData } from "../../elements/LogEntry/LogEntry";
+
+const allVisible: Record<LoggingLevel, boolean> = {
+  debug: true,
+  info: true,
+  notice: true,
+  warning: true,
+  error: true,
+  critical: true,
+  alert: true,
+  emergency: true,
+};
+
+const entries: LogEntryData[] = [
+  {
+    receivedAt: new Date("2026-03-17T10:00:00Z"),
+    params: { level: "info", data: "Server started", logger: "main" },
+  },
+  {
+    receivedAt: new Date("2026-03-17T10:00:01Z"),
+    params: { level: "error", data: "Failed to read", logger: "resources" },
+  },
+  {
+    receivedAt: new Date("2026-03-17T10:00:02Z"),
+    params: { level: "debug", data: "Loading config" },
+  },
+  {
+    receivedAt: new Date("2026-03-17T10:00:03Z"),
+    params: { level: "warning", data: { code: 42, msg: "deprecated" } },
+  },
+  {
+    receivedAt: new Date("2026-03-17T10:00:04Z"),
+    params: { level: "info", data: null },
+  },
+];
+
+const baseProps = {
+  entries,
+  filterText: "",
+  visibleLevels: allVisible,
+  autoScroll: true,
+  onToggleAutoScroll: vi.fn(),
+  onCopyAll: vi.fn(),
+  onClear: vi.fn(),
+  onExport: vi.fn(),
+};
+
+describe("LogStreamPanel", () => {
+  it("renders the title and toolbar buttons", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} />);
+    expect(screen.getByText("Log Stream")).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Clear" })).toBeInTheDocument();
+    expect(screen.getByRole("button", { name: "Export" })).toBeInTheDocument();
+    expect(
+      screen.getByRole("button", { name: "Copy All" }),
+    ).toBeInTheDocument();
+  });
+
+  it("renders log entries when provided", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} />);
+    expect(screen.getByText("Server started")).toBeInTheDocument();
+    expect(screen.getByText("Failed to read")).toBeInTheDocument();
+    expect(screen.getByText("Loading config")).toBeInTheDocument();
+  });
+
+  it("serializes object data as JSON", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} />);
+    expect(
+      screen.getByText('{"code":42,"msg":"deprecated"}'),
+    ).toBeInTheDocument();
+  });
+
+  it("renders empty state when there are no entries", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} entries={[]} />);
+    expect(screen.getByText("No log entries")).toBeInTheDocument();
+  });
+
+  it("renders empty state when all entries are filtered out", () => {
+    const hideAll: Record<LoggingLevel, boolean> = {
+      debug: false,
+      info: false,
+      notice: false,
+      warning: false,
+      error: false,
+      critical: false,
+      alert: false,
+      emergency: false,
+    };
+    renderWithMantine(
+      <LogStreamPanel {...baseProps} visibleLevels={hideAll} />,
+    );
+    expect(screen.getByText("No log entries")).toBeInTheDocument();
+  });
+
+  it("filters entries by visibleLevels", () => {
+    const onlyError: Record<LoggingLevel, boolean> = {
+      debug: false,
+      info: false,
+      notice: false,
+      warning: false,
+      error: true,
+      critical: false,
+      alert: false,
+      emergency: false,
+    };
+    renderWithMantine(
+      <LogStreamPanel {...baseProps} visibleLevels={onlyError} />,
+    );
+    expect(screen.getByText("Failed to read")).toBeInTheDocument();
+    expect(screen.queryByText("Server started")).not.toBeInTheDocument();
+    expect(screen.queryByText("Loading config")).not.toBeInTheDocument();
+  });
+
+  it("filters entries by filterText against the data", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} filterText="server" />);
+    expect(screen.getByText("Server started")).toBeInTheDocument();
+    expect(screen.queryByText("Failed to read")).not.toBeInTheDocument();
+  });
+
+  it("filters entries by filterText against the logger name", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} filterText="resources" />);
+    expect(screen.getByText("Failed to read")).toBeInTheDocument();
+    expect(screen.queryByText("Server started")).not.toBeInTheDocument();
+  });
+
+  it("filters entries by filterText against the level", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} filterText="debug" />);
+    expect(screen.getByText("Loading config")).toBeInTheDocument();
+    expect(screen.queryByText("Failed to read")).not.toBeInTheDocument();
+  });
+
+  it("invokes onClear when Clear is clicked", async () => {
+    const user = userEvent.setup();
+    const onClear = vi.fn();
+    renderWithMantine(<LogStreamPanel {...baseProps} onClear={onClear} />);
+    await user.click(screen.getByRole("button", { name: "Clear" }));
+    expect(onClear).toHaveBeenCalledTimes(1);
+  });
+
+  it("invokes onExport when Export is clicked", async () => {
+    const user = userEvent.setup();
+    const onExport = vi.fn();
+    renderWithMantine(<LogStreamPanel {...baseProps} onExport={onExport} />);
+    await user.click(screen.getByRole("button", { name: "Export" }));
+    expect(onExport).toHaveBeenCalledTimes(1);
+  });
+
+  it("invokes onCopyAll when Copy All is clicked", async () => {
+    const user = userEvent.setup();
+    const onCopyAll = vi.fn();
+    renderWithMantine(<LogStreamPanel {...baseProps} onCopyAll={onCopyAll} />);
+    await user.click(screen.getByRole("button", { name: "Copy All" }));
+    expect(onCopyAll).toHaveBeenCalledTimes(1);
+  });
+
+  it("invokes onToggleAutoScroll when the auto-scroll checkbox is clicked", async () => {
+    const user = userEvent.setup();
+    const onToggleAutoScroll = vi.fn();
+    renderWithMantine(
+      <LogStreamPanel {...baseProps} onToggleAutoScroll={onToggleAutoScroll} />,
+    );
+    await user.click(screen.getByLabelText("Auto-scroll"));
+    expect(onToggleAutoScroll).toHaveBeenCalledTimes(1);
+  });
+
+  it("renders auto-scroll checkbox with correct checked state", () => {
+    renderWithMantine(<LogStreamPanel {...baseProps} autoScroll={false} />);
+    expect(screen.getByLabelText("Auto-scroll")).not.toBeChecked();
+  });
+});