Capture hardening: deterministic env shim, extended lazy sweep, nav budget with bot-wall fast-fail

Salvaged and re-implemented from PR #15: - Deterministic environment shim (seeded Math.random, pinned-but-advancing Date consistent across constructor/now/getTime/valueOf/toISOString) so time/random-dependent pages capture reproducibly; epoch and seed are recorded run metadata, performance.now stays real for motion sampling - Post-snapshot lazy-asset discovery sweep for channels the walker misses: noscript contents (DOMParser), inline style url(), data-background(-image), img[loading=lazy] currentSrc - Navigation gets a total 90s budget, an early bot-wall probe that aborts with a pollution-style error instead of capturing garbage (WALL_RE now shared with the validator gate), and one fresh-context retry scoped to the initial nav on retryable failure classes only 505 tests pass (29 new), typecheck clean. Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
2026-07-04 13:49:14 -07:00
parent 3faf1ef043
commit 7e8863fc7e
7 changed files with 781 additions and 54 deletions
@@ -0,0 +1,85 @@
+import { describe, it, before, after } from "node:test";
+import assert from "node:assert/strict";
+import { chromium, type Browser, type Page } from "playwright";
+import { discoverLazyAssetsInPage } from "../src/capture/capture.js";
+
+const ESBUILD_SHIM =
+  "globalThis.__name = globalThis.__name || ((fn) => fn);" +
+  "globalThis.__defProp = globalThis.__defProp || Object.defineProperty;";
+
+const VW = 1280, VH = 800;
+const BASE = "https://example.com/page/";
+
+// ---------------------------------------------------------------------------
+// Item 2: extended lazy-asset discovery sweep (in-page discovery function).
+// ---------------------------------------------------------------------------
+describe("lazySweep: discoverLazyAssetsInPage", () => {
+  let browser: Browser;
+  before(async () => { browser = await chromium.launch(); });
+  after(async () => { await browser.close(); });
+
+  const discover = async (bodyHtml: string): Promise<string[]> => {
+    const page: Page = await browser.newPage();
+    await page.setViewportSize({ width: VW, height: VH });
+    await page.addInitScript(ESBUILD_SHIM);
+    // A <base> gives relative refs a stable absolute form to assert against.
+    await page.setContent(`<!doctype html><html><head><base href="${BASE}"></head><body>${bodyHtml}</body></html>`);
+    await page.evaluate(ESBUILD_SHIM);
+    const refs = await page.evaluate(discoverLazyAssetsInPage);
+    await page.close();
+    return refs;
+  };
+
+  it("discovers img/source src + srcset inside <noscript> fallback markup", async () => {
+    const refs = await discover(`
+      <noscript>
+        <img src="hero.jpg" srcset="hero-2x.jpg 2x, hero-3x.jpg 3x">
+        <picture><source srcset="alt.webp 1x, alt-2x.webp 2x"></picture>
+      </noscript>
+    `);
+    assert.ok(refs.includes(BASE + "hero.jpg"), "noscript img src");
+    assert.ok(refs.includes(BASE + "hero-2x.jpg"), "first srcset variant from noscript img");
+    assert.ok(refs.includes(BASE + "alt.webp"), "first srcset variant from noscript source");
+  });
+
+  it("discovers url(...) values from an element's inline style attribute", async () => {
+    const refs = await discover(`
+      <div style="background-image: url('bg.png'); color: red"></div>
+      <span style='background: url("sprite.svg") no-repeat'></span>
+    `);
+    assert.ok(refs.includes(BASE + "bg.png"), "inline background-image url()");
+    assert.ok(refs.includes(BASE + "sprite.svg"), "inline background shorthand url()");
+  });
+
+  it("discovers data-background / data-background-image (raw URL and url(...) forms)", async () => {
+    const refs = await discover(`
+      <div data-background="lazybg.jpg"></div>
+      <div data-background-image="url('lazybg2.png')"></div>
+    `);
+    assert.ok(refs.includes(BASE + "lazybg.jpg"), "raw data-background URL");
+    assert.ok(refs.includes(BASE + "lazybg2.png"), "url()-wrapped data-background-image");
+  });
+
+  it("discovers the resolved src of an img[loading=lazy]", async () => {
+    const refs = await discover(`<img loading="lazy" src="belowfold.jpg">`);
+    assert.ok(refs.includes(BASE + "belowfold.jpg"));
+  });
+
+  it("drops data: URIs and dedupes + sorts", async () => {
+    const refs = await discover(`
+      <div style="background: url('dup.png')"></div>
+      <div data-background="dup.png"></div>
+      <img loading="lazy" src="data:image/gif;base64,R0lGOD">
+    `);
+    assert.equal(refs.filter((u) => u.endsWith("dup.png")).length, 1, "deduped across channels");
+    assert.equal(refs.some((u) => u.startsWith("data:")), false, "data: URIs dropped");
+    assert.deepEqual(refs, [...refs].sort(), "sorted");
+  });
+
+  it("returns nothing for a page with no lazy references", async () => {
+    const refs = await discover(`<div><p>hello</p><img src="eager.jpg"></div>`);
+    // The eager <img src> is the walker's job, not this sweep — the sweep only harvests
+    // the channels the walker misses.
+    assert.deepEqual(refs, []);
+  });
+});