[tmashara]

What

A route string can carry its own selector: whitespace, then @, after the path. This adds no new flag.

renderdiff L R /a /b '/pricing @section.light-blue-footer-container' --selector .try-metabase-footer
'/pricing @section.cta'                # both sides /pricing, both shot at section.cta
'/pricing @.plans-v2::/plans @.plans'  # pair, one selector per side
'/pricing @.new::/pricing @.old'       # same path, different markup per side

Why

#26: you can now compare several components, plus whole pages, in one run without a config file. The first command above does the issue's four runs in one.

Syntax

• The pair split (::/) runs first. Then each side splits at its first \s+@, so a selector may contain @, ::, >> or spaces, e.g. '/c @[href="mailto:[email protected]"]'.
• The space is required, so /@user stays a path. Raw whitespace can't appear in a URL path or query, so every route that works today keeps its meaning: /@me, /npm/@scope/pkg, [email protected] and /@u@host. Sitemap and probe paths come from URL, which percent-encodes whitespace, so they can't hit the separator either.
• One quoted shell argument.
• These exit 2:
  • A selector on one side of a pair only: '/a::/b @.x' gives give a selector on both sides or neither.
  • An empty selector: '/a @' gives has an empty selector.

Precedence

A selector written in the route beats --selector / --left/right-selector, which beat a config route object's selector. The second half is unchanged. Config strings get the syntax for free, and since a string with @ is new syntax, this precedence breaks nothing that exists.

GitHub Action limitation

The Action's routes input splits on whitespace, so it can't carry this syntax. docs/github-action.md now says per-route selectors go in the config. I left the optional action.yml guard (reject a token starting with @) out. Add it if someone hits this.

How tested

• Five new dry-run tests in tests/unit/cli-args.test.ts:
  • precedence over --selector
  • per-side pair
  • /@me and [email protected] stay plain, and a selector with @ is kept whole
  • the two exit-2 errors
• All five fail without the src/config.ts change and pass with it.
• typecheck, lint, format:check, npm test (340) and npm run test:visual (347) all pass, after rebasing on 0.10.0.

Docs: README, docs/scoping.md, docs/github-action.md, skills/renderdiff/{SKILL,reference}.md, and --help.

Fixes #26

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