Address PR #197 review: test coverage + dedup + CI log capture

Code-review follow-ups (Approve-with-comments) for batch #197
(context badge #189 / e2e in CI #187 / inline MCP test #170):

- server: extract the duplicated chatContextWindow ::text->positive-int
  coercion (resolve() + getMasked()) into an exported parsePositiveInt
  helper and unit-test its branches (200000/1.9/0/-5/""/abc/undefined),
  closing the untested read-path gap.
- client: merge the two backward scans over messageRows into one pure,
  exported selectContextBadge helper (numerator and denominator still
  taken from the most recent row carrying EACH value) and unit-test the
  different-rows and fresh-zero-doesn't-shadow cases.
- client: extract the MCP "Test" button tristate presentation into a pure
  mcpTestButtonView helper (collapses the two parallel if/else chains) and
  unit-test idle/ok-with-tools/ok-no-tools/failed label+tooltip branches.
- ci: redirect the backgrounded prod server's stdout/stderr to a log file
  in e2e-mcp and cat it on failure, so a start-up crash is diagnosable
  instead of surfacing only as the generic health timeout.

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.test.ts

@@ -0,0 +1,59 @@
+import { describe, expect, it } from "vitest";
+import { mcpTestButtonView } from "./ai-mcp-server-test-view";
+
+/**
+ * Pure-helper tests for the inline "Test" button presentation. Covers the four
+ * states (idle / loading is handled by the component's `isPending`, so here:
+ * idle / ok-with-tools / ok-without-tools / failed) and the tooltip text
+ * branches that are easiest to break silently.
+ */
+// Identity-ish translator that echoes the key and interpolates {{n}} so the
+// label/tooltip branches are observable without the real i18n bundle.
+const t = (key: string, options?: Record<string, unknown>): string =>
+  options && "n" in options
+    ? key.replace("{{n}}", String((options as { n: unknown }).n))
+    : key;
+
+describe("mcpTestButtonView", () => {
+  it("idle when there is no result", () => {
+    expect(mcpTestButtonView(undefined, t)).toEqual({
+      state: "idle",
+      color: undefined,
+      variant: "default",
+      label: "Test",
+      tooltip: "",
+    });
+  });
+
+  it("ok with tools lists them in the tooltip", () => {
+    expect(mcpTestButtonView({ ok: true, tools: ["a", "b"] }, t)).toEqual({
+      state: "ok",
+      color: "green",
+      variant: "light",
+      label: "OK · 2",
+      tooltip: "a, b",
+    });
+  });
+
+  it('ok with zero tools shows "No tools available"', () => {
+    expect(mcpTestButtonView({ ok: true, tools: [] }, t)).toEqual({
+      state: "ok",
+      color: "green",
+      variant: "light",
+      label: "OK · 0",
+      tooltip: "No tools available",
+    });
+  });
+
+  it("failed surfaces the error text in the tooltip", () => {
+    expect(
+      mcpTestButtonView({ ok: false, error: "402: nope" }, t),
+    ).toEqual({
+      state: "failed",
+      color: "red",
+      variant: "light",
+      label: "Failed",
+      tooltip: "402: nope",
+    });
+  });
+});

apps/client/src/features/workspace/components/settings/components/ai-mcp-server-test-view.ts

@@ -0,0 +1,59 @@
+import type { IAiMcpServerTestResult } from "@/features/workspace/services/ai-mcp-server-service.ts";
+
+/** Minimal translator shape (i18next `t`): key + optional interpolation. */
+type Translate = (key: string, options?: Record<string, unknown>) => string;
+
+/**
+ * Presentation for the inline "Test" button, derived from the current test
+ * result tristate (no result yet / ok / failed). Color is never the only signal
+ * — the label and icon change too (a11y / colorblind-friendly). Kept as a single
+ * pure derivation (rather than two parallel if/else chains) so the button and
+ * tooltip can never drift apart, and so the text branches are unit-testable
+ * without rendering the row.
+ */
+export interface McpTestButtonView {
+  /** Tristate; the component maps this to the leftSection icon. */
+  state: "idle" | "ok" | "failed";
+  /** Mantine Button color; undefined = theme default (idle). */
+  color?: string;
+  /** Mantine Button variant. */
+  variant: string;
+  /** Translated button label. */
+  label: string;
+  /** Translated tooltip text; "" while there is no result (tooltip disabled). */
+  tooltip: string;
+}
+
+export function mcpTestButtonView(
+  result: IAiMcpServerTestResult | undefined,
+  t: Translate,
+): McpTestButtonView {
+  if (result?.ok) {
+    return {
+      state: "ok",
+      color: "green",
+      variant: "light",
+      label: t("OK · {{n}}", { n: result.tools.length }),
+      tooltip:
+        result.tools.length > 0
+          ? result.tools.join(", ")
+          : t("No tools available"),
+    };
+  }
+  if (result && result.ok === false) {
+    return {
+      state: "failed",
+      color: "red",
+      variant: "light",
+      label: t("Failed"),
+      tooltip: result.error,
+    };
+  }
+  return {
+    state: "idle",
+    color: undefined,
+    variant: "default",
+    label: t("Test"),
+    tooltip: "",
+  };
+}

apps/client/src/features/workspace/components/settings/components/ai-mcp-servers.tsx

@@ -31,6 +31,7 @@ import {
   useUpdateAiMcpServerMutation,
 } from "@/features/workspace/queries/ai-mcp-server-query.ts";
 import { IAiMcpServer } from "@/features/workspace/services/ai-mcp-server-service.ts";
+import { mcpTestButtonView } from "@/features/workspace/components/settings/components/ai-mcp-server-test-view.ts";
 import AiMcpServerForm from "./ai-mcp-server-form.tsx";
 
 /**
@@ -182,34 +183,22 @@ function AiMcpServerRow({
     // eslint-disable-next-line react-hooks/exhaustive-deps
   }, [server.url, server.transport, server.hasHeaders]);
 
-  // Tooltip text describes the cause/details; disabled while there is no result.
-  let tooltipLabel = "";
-  if (result?.ok) {
-    tooltipLabel =
-      result.tools.length > 0
-        ? result.tools.join(", ")
-        : t("No tools available");
-  } else if (result && result.ok === false) {
-    tooltipLabel = result.error;
-  }
-
-  // Pick the button presentation from the current test state. Color is never the
-  // only signal — the label changes too (a11y / colorblind-friendly).
-  let buttonColor: string | undefined;
-  let buttonVariant = "default";
-  let buttonIcon = <IconPlugConnected size={16} />;
-  let buttonLabel = t("Test");
-  if (result?.ok) {
-    buttonColor = "green";
-    buttonVariant = "light";
-    buttonIcon = <IconCheck size={16} />;
-    buttonLabel = t("OK · {{n}}", { n: result.tools.length });
-  } else if (result && result.ok === false) {
-    buttonColor = "red";
-    buttonVariant = "light";
-    buttonIcon = <IconX size={16} />;
-    buttonLabel = t("Failed");
-  }
+  // Single derivation of the button/tooltip presentation from the test tristate
+  // (idle / ok / failed), so the two can never drift apart. Tooltip is "" while
+  // there is no result; the icon is mapped from `view.state` below.
+  const view = mcpTestButtonView(result, t);
+  const tooltipLabel = view.tooltip;
+  const buttonColor = view.color;
+  const buttonVariant = view.variant;
+  const buttonLabel = view.label;
+  const buttonIcon =
+    view.state === "ok" ? (
+      <IconCheck size={16} />
+    ) : view.state === "failed" ? (
+      <IconX size={16} />
+    ) : (
+      <IconPlugConnected size={16} />
+    );
 
   return (
     <Group justify="space-between" wrap="nowrap">