feat: ship host metrics as a first-party in-process plugin

src/backend/tests/hosts/metrics-shared/common-utils.test.ts

@@ -0,0 +1,41 @@
+import { describe, it, expect } from "vitest";
+import {
+  toFixedNum,
+  kibToGiB,
+  encodePowerShellCommand,
+} from "../../../hosts/metrics-shared/common-utils.js";
+
+describe("toFixedNum", () => {
+  it("rounds to the requested digit count", () => {
+    expect(toFixedNum(3.14159, 2)).toBe(3.14);
+    expect(toFixedNum(3.14159, 0)).toBe(3);
+    expect(toFixedNum(2.5, 0)).toBe(3);
+  });
+
+  it("defaults to 2 digits", () => {
+    expect(toFixedNum(1.23456)).toBe(1.23);
+  });
+
+  it("returns null for non-finite or non-number input", () => {
+    expect(toFixedNum(null)).toBeNull();
+    expect(toFixedNum(undefined)).toBeNull();
+    expect(toFixedNum(NaN)).toBeNull();
+    expect(toFixedNum(Infinity)).toBeNull();
+  });
+});
+
+describe("kibToGiB", () => {
+  it("converts kibibytes to gibibytes", () => {
+    expect(kibToGiB(1024 * 1024)).toBe(1);
+    expect(kibToGiB(0)).toBe(0);
+    expect(kibToGiB(2 * 1024 * 1024)).toBe(2);
+  });
+});
+
+describe("encodePowerShellCommand", () => {
+  it("UTF-16LE base64 encodes the script, decodable back to the source", () => {
+    const script = "Write-Output 'hello'";
+    const encoded = encodePowerShellCommand(script);
+    expect(Buffer.from(encoded, "base64").toString("utf16le")).toBe(script);
+  });
+});