feat(browse): Puppeteer parity — load-html, screenshot --selector, viewport --scale, file:// (v1.1.0.0) (#1062)

* feat(browse): TabSession loadedHtml + command aliases + DX polish primitives

Adds the foundation layer for Puppeteer-parity features:

- TabSession.loadedHtml + setTabContent/getLoadedHtml/clearLoadedHtml —
  enables load-html content to survive context recreation (viewport --scale)
  via in-memory replay. ASCII lifecycle diagram in the source explains the
  clear-before-navigation contract.

- COMMAND_ALIASES + canonicalizeCommand() helper — single source of truth
  for name aliases (setcontent / set-content / setContent → load-html),
  consumed by server dispatch and chain prevalidation.

- buildUnknownCommandError() pure function — rich error messages with
  Levenshtein-based "Did you mean" suggestions (distance ≤ 2, input
  length ≥ 4 to skip 2-letter noise) and NEW_IN_VERSION upgrade hints.

- load-html registered in WRITE_COMMANDS + SCOPE_WRITE so scoped write
  tokens can use it.

- screenshot and viewport descriptions updated for upcoming flags.

- New browse/test/dx-polish.test.ts (15 tests): alias canonicalization,
  Levenshtein threshold + alphabetical tiebreak, short-input guard,
  NEW_IN_VERSION upgrade hint, alias + scope integration invariants.

No consumers yet — pure additive foundation. Safe to bisect on its own.

* feat(browse): accept file:// in goto with smart cwd/home-relative parsing

Extends validateNavigationUrl to accept file:// URLs scoped to safe dirs
(cwd + TEMP_DIR) via the existing validateReadPath policy. The workhorse is a
new normalizeFileUrl() helper that handles non-standard relative forms BEFORE
the WHATWG URL parser sees them:

    file:///abs/path.html       → unchanged
    file://./docs/page.html     → file://<cwd>/docs/page.html
    file://~/Documents/page.html → file://<HOME>/Documents/page.html
    file://docs/page.html       → file://<cwd>/docs/page.html
    file://localhost/abs/path   → unchanged
    file://host.example.com/... → rejected (UNC/network)
    file:// and file:///        → rejected (would list a directory)

Host heuristic rejects segments with '.', ':', '\\', '%', IPv6 brackets, or
Windows drive-letter patterns — so file://docs.v1/page.html, file://127.0.0.1/x,
file://[::1]/x, and file://C:/Users/x are explicit errors.

Uses fileURLToPath() + pathToFileURL() from node:url (never string-concat) so
URL escapes like %20 decode correctly and Node rejects encoded-slash traversal
(%2F..%2F) outright.

Signature change: validateNavigationUrl now returns Promise<string> (the
normalized URL) instead of Promise<void>. Existing callers that ignore the
return value still compile — they just don't benefit from smart-parsing until
updated in follow-up commits. Callers will be migrated in the next few commits
(goto, diff, newTab, restoreState).

Rewrites the url-validation test file: updates existing tests for the new
return type, adds 20+ new tests covering every normalizeFileUrl shape variant,
URL-encoding edge cases, and path-traversal rejection.

References: codex consult v3 P1 findings on URL parser semantics and fileURLToPath.

* feat(browse): BrowserManager deviceScaleFactor + setContent replay + file:// plumbing

Three tightly-coupled changes to BrowserManager, all in service of the
Puppeteer-parity workflow:

1. deviceScaleFactor + currentViewport tracking. New private fields (default
   scale=1, viewport=1280x720) + setDeviceScaleFactor(scale, w, h) method.
   deviceScaleFactor is a context-level Playwright option — changing it
   requires recreateContext(). The method validates (finite number, 1-3 cap,
   headed-mode rejected), stores new values, calls recreateContext(), and
   rolls back the fields on failure so a bad call doesn't leave inconsistent
   state. Context options at all three sites (launch, recreate happy path,
   recreate fallback) now honor the stored values instead of hardcoding
   1280x720.

2. BrowserState.loadedHtml + loadedHtmlWaitUntil. saveState captures per-tab
   loadedHtml from the session; restoreState replays it via newSession.
   setTabContent() — NOT bare page.setContent() — so TabSession.loadedHtml
   is rehydrated and survives *subsequent* scale changes. In-memory only,
   never persisted to disk (HTML may contain secrets or customer data).

3. newTab + restoreState now consume validateNavigationUrl's normalized
   return value. file://./x, file://~/x, and bare-segment forms now take
   effect at every navigation site, not just the top-level goto command.

Together these enable: load-html → viewport --scale 2 → viewport --scale 1.5
→ screenshot, with content surviving both context recreations. Codex v2 P0
flagged that bare page.setContent in restoreState would lose content on the
second scale change — this commit implements the rehydration path.

References: codex v2 P0 (TabSession rehydration), codex v3 P1 (4-caller
return value), plan Feature 3 + Feature 4.

* feat(browse): load-html, screenshot --selector, viewport --scale, alias dispatch

Wires the new handlers and dispatch logic that the previous commits made
possible:

write-commands.ts
- New 'load-html' case: validateReadPath for safe-dir scoping, stat-based
  actionable errors (not found, directory, oversize), extension allowlist
  (.html/.htm/.xhtml/.svg), magic-byte sniff with UTF-8 BOM strip accepting
  any <[a-zA-Z!?] markup opener (not just <!doctype — bare fragments like
  <div>...</div> work for setContent), 50MB cap via GSTACK_BROWSE_MAX_HTML_BYTES
  override, frame-context rejection. Calls session.setTabContent() so replay
  metadata is rehydrated.
- viewport command extended: optional [<WxH>], optional [--scale <n>],
  scale-only variant reads current size via page.viewportSize(). Invalid
  scale (NaN, Infinity, empty, out of 1-3) throws with named value. Headed
  mode rejected explicitly.
- clearLoadedHtml() called BEFORE goto/back/forward/reload navigation
  (not after) so a timed-out goto post-commit doesn't leave stale metadata
  that could resurrect on a later context recreation. Codex v2 P1 catch.
- goto uses validateNavigationUrl's normalized return value.

meta-commands.ts
- screenshot --selector <css> flag: explicit element-screenshot form.
  Rejects alongside positional selector (both = error), preserves --clip
  conflict at line 161, composes with --base64 at lines 168-174.
- chain canonicalizes each step with canonicalizeCommand — step shape is
  now { rawName, name, args } so prevalidation, dispatch, WRITE_COMMANDS.has,
  watch blocking, and result labels all use canonical names while audit
  labels show 'rawName→name' when aliased. Codex v3 P2 catch — prior shape
  only canonicalized at prevalidation and diverged everywhere else.
- diff command consumes validateNavigationUrl return value for both URLs.

server.ts
- Command canonicalization inserted immediately after parse, before scope /
  watch / tab-ownership / content-wrapping checks. rawCommand preserved for
  future audit (not wired into audit log in this commit — follow-up).
- Unknown-command handler replaced with buildUnknownCommandError() from
  commands.ts — produces 'Unknown command: X. Did you mean Y?' with optional
  upgrade hint for NEW_IN_VERSION entries.

security-audit-r2.test.ts
- Updated chain-loop marker from 'for (const cmd of commands)' to
  'for (const c of commands)' to match the new chain step shape. Same
  isWatching + BLOCKED invariants still asserted.

* chore: bump version and changelog (v1.1.0.0)

- VERSION: 1.0.0.0 → 1.1.0.0 (MINOR bump — new user-facing commands)
- package.json: matching version bump
- CHANGELOG.md: new 1.1.0.0 entry describing load-html, screenshot --selector,
  viewport --scale, file:// support, setContent replay, and DX polish in user
  voice with a dedicated Security section for file:// safe-dirs policy
- browse/SKILL.md.tmpl: adds pattern #12 "Render local HTML", pattern #13
  "Retina screenshots", and a full Puppeteer → browse cheatsheet with side-by-
  side API mapping and a worked tweet-renderer migration example
- browse/SKILL.md + SKILL.md: regenerated from templates via `bun run gen:skill-docs`
  to reflect the new command descriptions

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

* fix: pre-landing review fixes (9 findings from specialist + adversarial review)

Adversarial review (Claude subagent + Codex) surfaced 9 bugs across
CRITICAL/HIGH severity. All fixed:

1. tab-session.ts:setTabContent — state mutation moved AFTER the setContent
   await. Prior order left phantom HTML in replay metadata if setContent
   threw (timeout, browser crash), which a later viewport --scale would
   silently replay. Now loadedHtml is only recorded on successful load.

2. browser-manager.ts:setDeviceScaleFactor — rollback now forces a second
   recreateContext after restoring the old fields. The fallback path in
   the original recreateContext builds a blank context using whatever
   this.deviceScaleFactor/currentViewport hold at that moment (which were
   the NEW values we were trying to apply). Rolling back the fields without
   a second recreate left the live context at new-scale while state tracked
   old-scale. Now: restore fields, force re-recreate with old values, only
   if that ALSO fails do we return a combined error.

3. commands.ts:buildUnknownCommandError — Levenshtein tiebreak simplified
   to 'd <= 2 && d < bestDist' (strict less). Candidates are pre-sorted
   alphabetically, so first equal-distance wins by default. The prior
   '(d === bestDist && best !== undefined && cand < best)' clause was dead
   code.

4. tab-session.ts:onMainFrameNavigated — now clears loadedHtml, not just
   refs + frame. Without this, a user who load-html'd then clicked a link
   (or had a form submit / JS redirect / OAuth flow) would retain the stale
   replay metadata. The next viewport --scale would silently revert the
   tab to the ORIGINAL loaded HTML, losing whatever the post-navigation
   content was. Silent data corruption. Browser-emitted navigations trigger
   this path via wirePageEvents.

5. browser-manager.ts:saveState + restoreState — tab ownership now flows
   through BrowserState.owner. Without this, a scoped agent's viewport
   --scale would strand them: tab IDs change during recreate, ownership
   map held stale IDs, owner lookup failed. New IDs had no owner, so
   writes without tabId were denied (DoS). Worse, if the agent sent a
   stale tabId the server's swallowed-tab-switch-error path would let the
   command hit whatever tab was currently active (cross-tab authz bypass).
   Now: clear ownership before restore, re-add per-tab with new IDs.

6. meta-commands.ts:state load — disk-loaded state.pages is now explicit
   allowlist (url, isActive, storage:null) instead of object spread.
   Spreading accepted loadedHtml, loadedHtmlWaitUntil, and owner from a
   user-writable state file, letting a tampered state.json smuggle HTML
   past load-html's safe-dirs / extension / magic-byte / 50MB-cap
   validators, or forge tab ownership. Now stripped at the boundary.

7. url-validation.ts:normalizeFileUrl — preserves query string + fragment
   across normalization. file://./app.html?route=home#login previously
   resolved to a filesystem path that URL-encoded '?' as %3F and '#' as
   %23, or (for absolute forms) pathToFileURL dropped them entirely. SPAs
   and fixture URLs with query params 404'd or loaded the wrong route.
   Now: split on ?/# before path resolution, reattach after.

8. url-validation.ts:validateNavigationUrl — reattaches parsed.search +
   parsed.hash to the normalized file:// URL. Same fix at the main
   validator for absolute paths that go through fileURLToPath round-trip.

9. server.ts:writeAuditEntry — audit entries now include aliasOf when the
   user typed an alias ('setcontent' → cmd: 'load-html', aliasOf:
   'setcontent'). Previously the isAliased variable was computed but
   dropped, losing the raw input from the forensic trail. Completes the
   plan's codex v3 P2 requirement.

Also added bm.getCurrentViewport() and switched 'viewport --scale'-
without-size to read from it (more reliable than page.viewportSize() on
headed/transition contexts).

Tests pass: exit 0, no failures. Build clean.

* test: integration coverage for load-html, screenshot --selector, viewport --scale, replay, aliases

Adds 28 Playwright-integration tests that close the coverage gap flagged
by the ship-workflow coverage audit (50% → expected ~80%+).

**load-html (12 tests):**
- happy path loads HTML file, page text matches
- bare HTML fragments (<div>...</div>) accepted, not just full documents
- missing file arg throws usage
- non-.html extension rejected by allowlist
- /etc/passwd.html rejected by safe-dirs policy
- ENOENT path rejected with actionable "not found" error
- directory target rejected
- binary file (PNG magic bytes) disguised as .html rejected by magic-byte check
- UTF-8 BOM stripped before magic-byte check — BOM-prefixed HTML accepted
- --wait-until networkidle exercises non-default branch
- invalid --wait-until value rejected
- unknown flag rejected

**screenshot --selector (5 tests):**
- --selector flag captures element, validates Screenshot saved (element)
- conflicts with positional selector (both = error)
- conflicts with --clip (mutually exclusive)
- composes with --base64 (returns data:image/png;base64,...)
- missing value throws usage

**viewport --scale (5 tests):**
- WxH --scale 2 produces PNG with 2x element dimensions (parses IHDR bytes 16-23)
- --scale without WxH keeps current size + applies scale
- non-finite value (abc) throws "not a finite number"
- out-of-range (4, 0.5) throws "between 1 and 3"
- missing value throws

**setContent replay across context recreation (3 tests):**
- load-html → viewport --scale 2: content survives (hits setTabContent replay path)
- double cycle 2x → 1.5x: content still survives (proves TabSession rehydration)
- goto after load-html clears replay: subsequent viewport --scale does NOT
  resurrect the stale HTML (validates the onMainFrameNavigated fix)

**Command aliases (2 tests):**
- setcontent routes to load-html via chain canonicalization
- set-content (hyphenated) also routes — both end-to-end through chain dispatch

Fixture paths use /tmp (SAFE_DIRECTORIES entry) instead of $TMPDIR which is
/var/folders/... on macOS and outside the safe-dirs boundary. Chain result
labels use rawName→name format when an alias is resolved (matches the
meta-commands.ts chain refactor).

Full suite: exit 0, 223/223 pass.

* docs: update BROWSER.md + CHANGELOG for v1.1.0.0

BROWSER.md:
- Command reference table updated: goto now lists file:// support,
  load-html added to Navigate row, viewport flagged with --scale
  option, screenshot row shows --selector + --base64 flags
- Screenshot modes table adds the fifth mode (element crop via
  --selector flag) and notes the tag-selector-not-caught-positionally
  gotcha
- New "Retina screenshots — viewport --scale" subsection explains
  deviceScaleFactor mechanics, context recreation side effects, and
  headed-mode rejection
- New "Loading local HTML — goto file:// vs load-html" subsection
  explains the two paths, their tradeoffs (URL state, relative asset
  resolution), the safe-dirs policy, extension allowlist + magic-byte
  sniff, 50MB cap, setContent replay across recreateContext, and the
  alias routing (setcontent → load-html before scope check)

CHANGELOG.md (v1.1.0.0 security section expanded, no existing content
removed):
- State files cannot smuggle HTML or forge tab ownership (allowlist
  on disk-loaded page fields)
- Audit log records aliasOf when a canonical command was reached via
  an alias (setcontent → load-html)
- load-html content clears on real navigations (clicks, form submits,
  JS redirects) — not just explicit goto. Also notes SPA query/fragment
  preservation for goto file://

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

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
Garry Tan
2026-04-18 23:25:33 +08:00
committed by GitHub
parent 4d2c8d94d0
commit c15b805cd8
20 changed files with 1439 additions and 92 deletions
+103 -3
View File
@@ -21,6 +21,7 @@ export const READ_COMMANDS = new Set([
export const WRITE_COMMANDS = new Set([
'goto', 'back', 'forward', 'reload',
'load-html',
'click', 'fill', 'select', 'hover', 'type', 'press', 'scroll', 'wait',
'viewport', 'cookie', 'cookie-import', 'cookie-import-browser', 'header', 'useragent',
'upload', 'dialog-accept', 'dialog-dismiss',
@@ -64,7 +65,8 @@ export function wrapUntrustedContent(result: string, url: string): string {
export const COMMAND_DESCRIPTIONS: Record<string, { category: string; description: string; usage?: string }> = {
// Navigation
'goto': { category: 'Navigation', description: 'Navigate to URL', usage: 'goto <url>' },
'goto': { category: 'Navigation', description: 'Navigate to URL (http://, https://, or file:// scoped to cwd/TEMP_DIR)', usage: 'goto <url>' },
'load-html': { category: 'Navigation', description: 'Load a local HTML file via setContent (no HTTP server needed). For self-contained HTML (inline CSS/JS, data URIs). For HTML on disk, goto file://... is often cleaner.', usage: 'load-html <file> [--wait-until load|domcontentloaded|networkidle]' },
'back': { category: 'Navigation', description: 'History back' },
'forward': { category: 'Navigation', description: 'History forward' },
'reload': { category: 'Navigation', description: 'Reload page' },
@@ -99,7 +101,7 @@ export const COMMAND_DESCRIPTIONS: Record<string, { category: string; descriptio
'scroll': { category: 'Interaction', description: 'Scroll element into view, or scroll to page bottom if no selector', usage: 'scroll [sel]' },
'wait': { category: 'Interaction', description: 'Wait for element, network idle, or page load (timeout: 15s)', usage: 'wait <sel|--networkidle|--load>' },
'upload': { category: 'Interaction', description: 'Upload file(s)', usage: 'upload <sel> <file> [file2...]' },
'viewport':{ category: 'Interaction', description: 'Set viewport size', usage: 'viewport <WxH>' },
'viewport':{ category: 'Interaction', description: 'Set viewport size and optional deviceScaleFactor (1-3, for retina screenshots). --scale requires a context rebuild.', usage: 'viewport [<WxH>] [--scale <n>]' },
'cookie': { category: 'Interaction', description: 'Set cookie on current page domain', usage: 'cookie <name>=<value>' },
'cookie-import': { category: 'Interaction', description: 'Import cookies from JSON file', usage: 'cookie-import <json>' },
'cookie-import-browser': { category: 'Interaction', description: 'Import cookies from installed Chromium browsers (opens picker, or use --domain for direct import)', usage: 'cookie-import-browser [browser] [--domain d]' },
@@ -112,7 +114,7 @@ export const COMMAND_DESCRIPTIONS: Record<string, { category: string; descriptio
'scrape': { category: 'Extraction', description: 'Bulk download all media from page. Writes manifest.json', usage: 'scrape <images|videos|media> [--selector sel] [--dir path] [--limit N]' },
'archive': { category: 'Extraction', description: 'Save complete page as MHTML via CDP', usage: 'archive [path]' },
// Visual
'screenshot': { category: 'Visual', description: 'Save screenshot (supports element crop via CSS/@ref, --clip region, --viewport)', usage: 'screenshot [--viewport] [--clip x,y,w,h] [selector|@ref] [path]' },
'screenshot': { category: 'Visual', description: 'Save screenshot. --selector targets a specific element (explicit flag form). Positional selectors starting with ./#/@/[ still work.', usage: 'screenshot [--selector <css>] [--viewport] [--clip x,y,w,h] [--base64] [selector|@ref] [path]' },
'pdf': { category: 'Visual', description: 'Save as PDF', usage: 'pdf [path]' },
'responsive': { category: 'Visual', description: 'Screenshots at mobile (375x812), tablet (768x1024), desktop (1280x720). Saves as {prefix}-mobile.png etc.', usage: 'responsive [prefix]' },
'diff': { category: 'Visual', description: 'Text diff between pages', usage: 'diff <url1> <url2>' },
@@ -161,3 +163,101 @@ for (const cmd of allCmds) {
for (const key of descKeys) {
if (!allCmds.has(key)) throw new Error(`COMMAND_DESCRIPTIONS has unknown command: ${key}`);
}
/**
* Command aliases — user-friendly names that route to canonical commands.
*
* Single source of truth: server.ts dispatch and meta-commands.ts chain prevalidation
* both import `canonicalizeCommand()`, so aliases resolve identically everywhere.
*
* When adding a new alias: keep the alias name guessable (e.g. setcontent → load-html
* helps agents migrating from Puppeteer's page.setContent()).
*/
export const COMMAND_ALIASES: Record<string, string> = {
'setcontent': 'load-html',
'set-content': 'load-html',
'setContent': 'load-html',
};
/** Resolve an alias to its canonical command name. Non-aliases pass through unchanged. */
export function canonicalizeCommand(cmd: string): string {
return COMMAND_ALIASES[cmd] ?? cmd;
}
/**
* Commands added in specific versions — enables future "this command was added in vX"
* upgrade hints in unknown-command errors. Only helps agents on *newer* browse builds
* that encounter typos of recently-added commands; does NOT help agents on old builds
* that type a new command (they don't have this map).
*/
export const NEW_IN_VERSION: Record<string, string> = {
'load-html': '0.19.0.0',
};
/**
* Levenshtein distance (dynamic programming).
* O(a.length * b.length) — fast for command name sizes (<20 chars).
*/
function levenshtein(a: string, b: string): number {
if (a === b) return 0;
if (a.length === 0) return b.length;
if (b.length === 0) return a.length;
const m: number[][] = [];
for (let i = 0; i <= a.length; i++) m.push([i, ...Array(b.length).fill(0)]);
for (let j = 0; j <= b.length; j++) m[0][j] = j;
for (let i = 1; i <= a.length; i++) {
for (let j = 1; j <= b.length; j++) {
const cost = a[i - 1] === b[j - 1] ? 0 : 1;
m[i][j] = Math.min(m[i - 1][j] + 1, m[i][j - 1] + 1, m[i - 1][j - 1] + cost);
}
}
return m[a.length][b.length];
}
/**
* Build an actionable error message for an unknown command.
*
* Pure function — takes the full command set + alias map + version map as args so tests
* can exercise the synthetic "older-version" case without mutating any global state.
*
* 1. Always names the input.
* 2. If Levenshtein distance ≤ 2 AND input.length ≥ 4, suggests the closest match
* (alphabetical tiebreak for determinism). Short-input guard prevents noisy
* suggestions for typos of 2-letter commands like 'js' or 'is'.
* 3. If the input appears in newInVersion, appends an upgrade hint. Honesty caveat:
* this only fires on builds that have this handler AND the map entry; agents on
* older builds hitting a newly-added command won't see it. Net benefit compounds
* as more commands land.
*/
export function buildUnknownCommandError(
command: string,
commandSet: Set<string>,
aliasMap: Record<string, string> = COMMAND_ALIASES,
newInVersion: Record<string, string> = NEW_IN_VERSION,
): string {
let msg = `Unknown command: '${command}'.`;
// Suggestion via Levenshtein, gated on input length to avoid noisy short-input matches.
// Candidates are pre-sorted alphabetically, so strict "d < bestDist" gives us the
// closest match with alphabetical tiebreak for free — first equal-distance candidate
// wins because subsequent equal-distance candidates fail the strict-less check.
if (command.length >= 4) {
let best: string | undefined;
let bestDist = 3; // sentinel: distance 3 would be rejected by the <= 2 gate below
const candidates = [...commandSet, ...Object.keys(aliasMap)].sort();
for (const cand of candidates) {
const d = levenshtein(command, cand);
if (d <= 2 && d < bestDist) {
best = cand;
bestDist = d;
}
}
if (best) msg += ` Did you mean '${best}'?`;
}
if (newInVersion[command]) {
msg += ` This command was added in browse v${newInVersion[command]}. Upgrade: cd ~/.claude/skills/gstack && git pull && bun run build.`;
}
return msg;
}