expand shim coverage, additional fs shims, add light stream shim

packages/shim/src/node/assert.test.js

@@ -0,0 +1,30 @@
+import { describe, it, expect } from "vitest";
+import { assertShim as assert } from "./assert.js";
+
+describe("assert shim", () => {
+  it("is callable and throws on a falsy value", () => {
+    expect(() => assert(false)).toThrow();
+    expect(() => assert(true)).not.toThrow();
+  });
+
+  it("equal throws on mismatch and passes on loose match", () => {
+    expect(() => assert.equal(1, 2)).toThrow();
+    expect(() => assert.equal(1, 1)).not.toThrow();
+    expect(() => assert.equal(1, "1")).not.toThrow();
+  });
+
+  it("strictEqual distinguishes type", () => {
+    expect(() => assert.strictEqual(1, "1")).toThrow();
+    expect(() => assert.strictEqual(1, 1)).not.toThrow();
+  });
+
+  it("throws() verifies that a function threw", () => {
+    expect(() =>
+      assert.throws(() => {
+        throw new Error("x");
+      }),
+    ).not.toThrow();
+
+    expect(() => assert.throws(() => {})).toThrow();
+  });
+});