From f9111c06a7d5f78e50b11dd1e15033d5a30f2ba3 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Sun, 2 Aug 2026 23:47:18 -0400
Subject: [PATCH] test(extension): unit suite for lib/ + version-consistency
 specs

extension/ had no test harness at all -- web-ext lint was the only signal, so
the URL-normalization fix in 8214afe shipped with nothing exercising it.

Adds vitest (mirroring frontend/vitest.config.js) and three specs:

- url.spec.js       normalizeApiUrl / webRootFromApiUrl, including the #2393
                    regression: instance-root input must reach /api/credentials,
                    idempotence, trailing-slash and whitespace handling, and
                    that empty input never yields a bare "/api" (which
                    isConfigured() would read as configured).
- platforms.spec.js getPlatformFromUrl / isArtistPage, pinning the #1485
                    regression -- all three Patreon creator URL shapes
                    (bare, /c/, /cw/) plus inner pages, with nav pages
                    excluded -- and table-integrity checks.
- version.spec.js   manifest.json and package.json versions in lockstep,
                    AMO-safe version format, and url.js ordered before api.js
                    in background.scripts (classic scripts share one scope, so
                    a reorder is a runtime ReferenceError with no build signal).

Specs load lib/*.js by evaluating the real file as a classic script
(test/helpers/loadLib.js) instead of adding module.exports shims to production
code that would never run in the browser. The suite therefore exercises exactly
the bytes packaged into the XPI.

Two packaging consequences, both handled:

- web-ext would otherwise bundle test/ and vitest.config.js INTO the XPI;
  both are now in --ignore-files across all four web-ext scripts.
- ci.yml's extension-version guard must ignore the same paths, or editing a
  spec would demand a pointless version bump. The dangerous drift direction is
  the opposite one -- a guard exclusion for a file that DOES ship would let a
  real change pass unnoticed -- so version.spec.js asserts every :(exclude) in
  ci.yml appears in --ignore-files.

extension.yml also triggers on ci.yml now, since version.spec.js reads it.

Refs #2393, #2397

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
---
 .forgejo/workflows/ci.yml         |  11 ++-
 .forgejo/workflows/extension.yml  |  17 +++-
 ci-requirements.md                |  18 +++++
 extension/package.json            |  10 ++-
 extension/test/helpers/loadLib.js |  29 +++++++
 extension/test/platforms.spec.js  | 127 ++++++++++++++++++++++++++++++
 extension/test/url.spec.js        |  93 ++++++++++++++++++++++
 extension/test/version.spec.js    |  71 +++++++++++++++++
 extension/vitest.config.js        |  13 +++
 9 files changed, 379 insertions(+), 10 deletions(-)
 create mode 100644 extension/test/helpers/loadLib.js
 create mode 100644 extension/test/platforms.spec.js
 create mode 100644 extension/test/url.spec.js
 create mode 100644 extension/test/version.spec.js
 create mode 100644 extension/vitest.config.js

diff --git a/.forgejo/workflows/ci.yml b/.forgejo/workflows/ci.yml
index 184e9b3..5f17846 100644
--- a/.forgejo/workflows/ci.yml
+++ b/.forgejo/workflows/ci.yml
@@ -123,13 +123,18 @@ jobs:
           fi
           # Exclusions mirror --ignore-files in extension/package.json's web-ext
           # scripts: these files are not packaged into the XPI, so touching them
-          # (e.g. Renovate bumping the web-ext devDep) changes nothing shipped
-          # and must not demand a version bump.
+          # (e.g. Renovate bumping the web-ext devDep, or editing a spec)
+          # changes nothing shipped and must not demand a version bump.
+          # KEEP IN SYNC with --ignore-files — a file packaged into the XPI but
+          # excluded here is exactly the silent-stale-ship this job exists to
+          # prevent. test/version.spec.js pins the two lists' shared intent.
           CHANGED=$(git diff --name-only "$BASE" HEAD -- extension/ \
             ':(exclude)extension/package.json' \
             ':(exclude)extension/package-lock.json' \
             ':(exclude)extension/README.md' \
-            ':(exclude)extension/.gitignore')
+            ':(exclude)extension/.gitignore' \
+            ':(exclude)extension/vitest.config.js' \
+            ':(exclude)extension/test/**')
           if [ -z "$CHANGED" ]; then
             echo "No packaged extension files changed since $BASE — nothing to guard."
             echo "OK: extension version $PKG"
diff --git a/.forgejo/workflows/extension.yml b/.forgejo/workflows/extension.yml
index 3a50314..a67c578 100644
--- a/.forgejo/workflows/extension.yml
+++ b/.forgejo/workflows/extension.yml
@@ -1,5 +1,5 @@
 name: extension
-# Lint-only workflow. The sign-and-publish dance moved into build.yml's
+# Lint + unit tests. The sign-and-publish dance moved into build.yml's
 # `sign-extension` job (2026-05-25) — `:latest` now always bundles the XPI
 # because sign-extension runs as a build-web dependency in the SAME workflow,
 # eliminating the prior race between build.yml and a separate extension.yml.
@@ -10,10 +10,15 @@ on:
     paths:
       - 'extension/**'
       - '.forgejo/workflows/extension.yml'
+      # test/version.spec.js asserts ci.yml's extension-version guard never
+      # ignores a file web-ext actually packages, so a ci.yml-only edit can
+      # break this suite and must trigger it.
+      - '.forgejo/workflows/ci.yml'
   pull_request:
     branches: [main]
     paths:
       - 'extension/**'
+      - '.forgejo/workflows/ci.yml'
   workflow_dispatch:
 
 jobs:
@@ -23,7 +28,13 @@ jobs:
       image: node:24-bookworm-slim
     steps:
       - uses: actions/checkout@v4
-      - name: Install web-ext
-        run: cd extension && npm install --no-save --no-audit --no-fund
+      # Not --no-save: vitest and web-ext are both real devDependencies now,
+      # and the suite needs vitest resolvable from node_modules.
+      - name: Install dev dependencies
+        run: cd extension && npm install --no-audit --no-fund
       - name: Lint
         run: cd extension && npm run lint
+      # Pure-logic specs over lib/url.js and lib/platforms.js plus manifest /
+      # package version-consistency checks. No browser, no network.
+      - name: Unit tests
+        run: cd extension && npm run test:unit
diff --git a/ci-requirements.md b/ci-requirements.md
index c5cebd3..c7a5438 100644
--- a/ci-requirements.md
+++ b/ci-requirements.md
@@ -13,10 +13,20 @@ git.fabledsword.com/bvandeusen/ci-python:3.14
 - node (frontend job: `npm install` + vitest + vite build)
 - docker CLI + buildx (`.forgejo/workflows/build.yml`: build-web, build-ml — Fabled-Git registry push)
 
+## Secondary runtime image
+
+node:24-bookworm-slim — `.forgejo/workflows/extension.yml` only.
+
+The extension lane is the one job that does NOT run on `ci-python:3.14`: it
+needs a current Node for `web-ext` and vitest and nothing Python at all. Kept
+on the upstream slim image rather than adding a Node toolchain to `ci-python`,
+per `docs/process.md`'s "add deps to the image when used by >1 project".
+
 ## Per-job tool installs
 
 - `pip install -r requirements.txt pytest pytest-asyncio` — in `backend-lint-and-test` and `integration` jobs
 - `npm install --no-audit --no-fund` — in `frontend-build` job
+- `npm install --no-audit --no-fund` — in `extension.yml`'s `lint` job (web-ext + vitest)
 
 ## Notes
 
@@ -35,3 +45,11 @@ git.fabledsword.com/bvandeusen/ci-python:3.14
   memory bans `npm install` locally). Using `npm install` rather than
   `npm ci` until a lockfile lands.
 - No `imagemagick` / `pandoc` per-job installs needed.
+- `extension/`'s vitest specs load `lib/*.js` by evaluating the real file as a
+  classic script (`test/helpers/loadLib.js`) rather than adding `module.exports`
+  shims to production code — the libs ship as `background.scripts`, not ES
+  modules, so the specs exercise exactly the bytes packaged into the XPI.
+- Extension test files are excluded from the XPI via `--ignore-files` in
+  `extension/package.json`, and the same paths are excluded from `ci.yml`'s
+  `extension-version` guard. Those two lists must agree — `test/version.spec.js`
+  asserts the guard never ignores a file web-ext actually packages.
diff --git a/extension/package.json b/extension/package.json
index 8230440..c441e82 100644
--- a/extension/package.json
+++ b/extension/package.json
@@ -4,12 +4,14 @@
   "private": true,
   "description": "Firefox extension for FabledCurator",
   "scripts": {
-    "lint":  "web-ext lint --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore",
-    "start": "web-ext run --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore --firefox=firefox",
-    "build": "web-ext build --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore --overwrite-dest",
-    "sign":  "web-ext sign --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore --channel=unlisted --api-key=$WEB_EXT_API_KEY --api-secret=$WEB_EXT_API_SECRET"
+    "lint":  "web-ext lint --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\"",
+    "start": "web-ext run --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\" --firefox=firefox",
+    "build": "web-ext build --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\" --overwrite-dest",
+    "sign":  "web-ext sign --source-dir=. --no-config-discovery --ignore-files package.json package-lock.json web-ext-artifacts node_modules README.md .gitignore vitest.config.js \"test/**\" --channel=unlisted --api-key=$WEB_EXT_API_KEY --api-secret=$WEB_EXT_API_SECRET",
+    "test:unit": "vitest run"
   },
   "devDependencies": {
+    "vitest": "^4.0.0",
     "web-ext": "^10.0.0"
   }
 }
diff --git a/extension/test/helpers/loadLib.js b/extension/test/helpers/loadLib.js
new file mode 100644
index 0000000..e5ded02
--- /dev/null
+++ b/extension/test/helpers/loadLib.js
@@ -0,0 +1,29 @@
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import path from 'node:path'
+
+const LIB_DIR = path.join(path.dirname(fileURLToPath(import.meta.url)), '..', '..', 'lib')
+
+/**
+ * Load an extension lib and hand back the globals it declares.
+ *
+ * The files under lib/ are CLASSIC scripts, not ES modules: manifest.json
+ * lists them in `background.scripts` and options.html pulls them in with a
+ * plain <script> tag, so they declare bare functions into a shared scope and
+ * export nothing. Rather than bolt a `module.exports` shim onto production
+ * code that would never run in the browser, evaluate the real file the same
+ * way the browser does — as a script body — and pick the declarations back out.
+ *
+ * This means the specs exercise the exact bytes that get packaged into the
+ * XPI. Only usable for libs that touch no browser APIs at load time
+ * (url.js, platforms.js); cookies.js and api.js reference `browser.*` and
+ * would need stubbing, which is why they aren't loaded this way.
+ *
+ * @param {string} filename e.g. 'url.js'
+ * @param {string[]} names  declarations to return, e.g. ['normalizeApiUrl']
+ */
+export function loadLib(filename, names) {
+  const source = readFileSync(path.join(LIB_DIR, filename), 'utf8')
+  const factory = new Function(`${source}\nreturn { ${names.join(', ')} }`)
+  return factory()
+}
diff --git a/extension/test/platforms.spec.js b/extension/test/platforms.spec.js
new file mode 100644
index 0000000..deb9f97
--- /dev/null
+++ b/extension/test/platforms.spec.js
@@ -0,0 +1,127 @@
+import { describe, it, expect } from 'vitest'
+import { loadLib } from './helpers/loadLib.js'
+
+const { getPlatformFromUrl, isArtistPage, PLATFORMS, PLATFORM_ARTIST_PATTERNS } = loadLib(
+  'platforms.js',
+  ['getPlatformFromUrl', 'isArtistPage', 'PLATFORMS', 'PLATFORM_ARTIST_PATTERNS']
+)
+
+describe('getPlatformFromUrl', () => {
+  it('identifies each platform from a domain URL', () => {
+    expect(getPlatformFromUrl('https://www.patreon.com/Atole')).toBe('patreon')
+    expect(getPlatformFromUrl('https://subscribestar.adult/someone')).toBe('subscribestar')
+    expect(getPlatformFromUrl('https://www.hentai-foundry.com/user/someone')).toBe('hentaifoundry')
+    expect(getPlatformFromUrl('https://discord.com/channels/@me')).toBe('discord')
+    expect(getPlatformFromUrl('https://www.pixiv.net/en/users/123')).toBe('pixiv')
+    expect(getPlatformFromUrl('https://www.deviantart.com/someone')).toBe('deviantart')
+  })
+
+  it('accepts http as well as https, with or without www', () => {
+    expect(getPlatformFromUrl('http://patreon.com/Atole')).toBe('patreon')
+    expect(getPlatformFromUrl('https://www.patreon.com/Atole')).toBe('patreon')
+  })
+
+  it('returns null for unrelated hosts', () => {
+    expect(getPlatformFromUrl('https://example.com/patreon.com')).toBe(null)
+    expect(getPlatformFromUrl('https://not-patreon.com/Atole')).toBe(null)
+    expect(getPlatformFromUrl('')).toBe(null)
+  })
+})
+
+describe('isArtistPage', () => {
+  // Regression cases from issue #1485: the Add-to-FC button vanished once the
+  // operator SUBSCRIBED to a creator, because Patreon serves subscribed users
+  // the /cw/ ("creator workspace") URL and the pattern only matched the bare
+  // root. All three creator URL shapes must match, plus inner pages — the
+  // button matters most exactly when you're subscribed.
+  it('matches all three Patreon creator URL shapes', () => {
+    expect(isArtistPage('https://www.patreon.com/Atole', 'patreon')).toBe(true)
+    expect(isArtistPage('https://www.patreon.com/c/Atole', 'patreon')).toBe(true)
+    expect(isArtistPage('https://www.patreon.com/cw/Atole', 'patreon')).toBe(true)
+  })
+
+  it('matches Patreon creator inner pages', () => {
+    expect(isArtistPage('https://www.patreon.com/cw/Atole/posts', 'patreon')).toBe(true)
+    expect(isArtistPage('https://www.patreon.com/Atole/membership', 'patreon')).toBe(true)
+  })
+
+  it('excludes Patreon navigation pages that are not creators', () => {
+    for (const nav of ['home', 'search', 'messages', 'notifications', 'library', 'settings']) {
+      expect(isArtistPage(`https://www.patreon.com/${nav}`, 'patreon')).toBe(false)
+      expect(isArtistPage(`https://www.patreon.com/${nav}/anything`, 'patreon')).toBe(false)
+    }
+  })
+
+  it('matches SubscribeStar creator roots on both TLDs but not feed pages', () => {
+    expect(isArtistPage('https://subscribestar.adult/someone', 'subscribestar')).toBe(true)
+    expect(isArtistPage('https://subscribestar.com/someone', 'subscribestar')).toBe(true)
+    expect(isArtistPage('https://subscribestar.adult/feed', 'subscribestar')).toBe(false)
+    expect(isArtistPage('https://subscribestar.adult/messages', 'subscribestar')).toBe(false)
+  })
+
+  it('matches Hentai Foundry user pages only', () => {
+    expect(isArtistPage('https://www.hentai-foundry.com/user/someone', 'hentaifoundry')).toBe(true)
+    expect(isArtistPage('https://www.hentai-foundry.com/pictures/popular', 'hentaifoundry')).toBe(
+      false
+    )
+  })
+
+  it('matches Pixiv numeric user pages, with or without the /en/ prefix', () => {
+    expect(isArtistPage('https://www.pixiv.net/users/12345', 'pixiv')).toBe(true)
+    expect(isArtistPage('https://www.pixiv.net/en/users/12345', 'pixiv')).toBe(true)
+    expect(isArtistPage('https://www.pixiv.net/en/artworks/999', 'pixiv')).toBe(false)
+  })
+
+  it('excludes DeviantArt navigation roots', () => {
+    expect(isArtistPage('https://www.deviantart.com/someone', 'deviantart')).toBe(true)
+    expect(isArtistPage('https://www.deviantart.com/home', 'deviantart')).toBe(false)
+    expect(isArtistPage('https://www.deviantart.com/watch', 'deviantart')).toBe(false)
+  })
+
+  it('returns false for a platform with no artist pattern (discord)', () => {
+    expect(isArtistPage('https://discord.com/channels/@me', 'discord')).toBe(false)
+  })
+
+  it('returns false for an unknown platform key', () => {
+    expect(isArtistPage('https://www.patreon.com/Atole', 'nope')).toBe(false)
+  })
+})
+
+describe('platform table integrity', () => {
+  it('gives every artist pattern a corresponding platform entry', () => {
+    // A pattern keyed to a platform that no longer exists is dead code that
+    // silently never fires; the reverse (a platform with no pattern) is the
+    // legitimate discord case, so only this direction is an error.
+    for (const key of Object.keys(PLATFORM_ARTIST_PATTERNS)) {
+      expect(Object.keys(PLATFORMS)).toContain(key)
+    }
+  })
+
+  it('gives every platform the fields the popup renders', () => {
+    for (const [key, platform] of Object.entries(PLATFORMS)) {
+      expect(platform.name, `${key}.name`).toBeTruthy()
+      expect(platform.color, `${key}.color`).toMatch(/^#[0-9A-Fa-f]{6}$/)
+      expect(['cookies', 'token'], `${key}.authType`).toContain(platform.authType)
+      expect(platform.urlPattern, `${key}.urlPattern`).toBeInstanceOf(RegExp)
+      expect(Array.isArray(platform.domains), `${key}.domains`).toBe(true)
+      expect(platform.domains.length, `${key}.domains`).toBeGreaterThan(0)
+    }
+  })
+
+  it('keeps every artist URL matched by its own platform pattern too', () => {
+    // isArtistPage is only ever consulted after getPlatformFromUrl resolves a
+    // key, so an artist pattern matching a URL its platform's urlPattern
+    // rejects would be unreachable.
+    const samples = {
+      patreon: 'https://www.patreon.com/cw/Atole',
+      subscribestar: 'https://subscribestar.adult/someone',
+      hentaifoundry: 'https://www.hentai-foundry.com/user/someone',
+      deviantart: 'https://www.deviantart.com/someone',
+      pixiv: 'https://www.pixiv.net/en/users/12345'
+    }
+    for (const [key, url] of Object.entries(samples)) {
+      expect(isArtistPage(url, key), `${key} artist pattern`).toBe(true)
+      expect(getPlatformFromUrl(url), `${key} urlPattern`).toBe(key)
+    }
+  })
+})
diff --git a/extension/test/url.spec.js b/extension/test/url.spec.js
new file mode 100644
index 0000000..a5fca10
--- /dev/null
+++ b/extension/test/url.spec.js
@@ -0,0 +1,93 @@
+import { describe, it, expect } from 'vitest'
+import { loadLib } from './helpers/loadLib.js'
+
+const { normalizeApiUrl, webRootFromApiUrl } = loadLib('url.js', [
+  'normalizeApiUrl',
+  'webRootFromApiUrl'
+])
+
+describe('normalizeApiUrl', () => {
+  // The bug this exists for (issue #2393): the instance root was accepted and
+  // stored verbatim, so every request went to /credentials instead of
+  // /api/credentials. That path is a Vue router route, so the SPA catch-all
+  // answered GET with 200 HTML and rejected POST with 405 — which read as a
+  // backend bug rather than a URL one.
+  it('appends /api to an instance root', () => {
+    expect(normalizeApiUrl('http://curator.traefik.internal')).toBe(
+      'http://curator.traefik.internal/api'
+    )
+  })
+
+  it('leaves an API root alone rather than doubling the suffix', () => {
+    expect(normalizeApiUrl('http://curator.traefik.internal/api')).toBe(
+      'http://curator.traefik.internal/api'
+    )
+  })
+
+  it('is idempotent', () => {
+    const once = normalizeApiUrl('http://curator.example.com')
+    expect(normalizeApiUrl(once)).toBe(once)
+  })
+
+  it('strips trailing slashes before deciding', () => {
+    expect(normalizeApiUrl('http://curator.example.com/')).toBe('http://curator.example.com/api')
+    expect(normalizeApiUrl('http://curator.example.com///')).toBe('http://curator.example.com/api')
+    expect(normalizeApiUrl('http://curator.example.com/api/')).toBe('http://curator.example.com/api')
+  })
+
+  it('trims surrounding whitespace (paste artifacts)', () => {
+    expect(normalizeApiUrl('  http://curator.example.com  ')).toBe(
+      'http://curator.example.com/api'
+    )
+  })
+
+  it('matches the /api suffix case-insensitively', () => {
+    expect(normalizeApiUrl('http://curator.example.com/API')).toBe('http://curator.example.com/API')
+  })
+
+  it('returns empty string for empty/nullish input, never a bare "/api"', () => {
+    // isConfigured() gates on truthiness, so a bogus '/api' here would read as
+    // "configured" and produce a request against the options page's own origin.
+    expect(normalizeApiUrl('')).toBe('')
+    expect(normalizeApiUrl('   ')).toBe('')
+    expect(normalizeApiUrl(null)).toBe('')
+    expect(normalizeApiUrl(undefined)).toBe('')
+  })
+
+  it('does not treat a path merely containing "api" as the suffix', () => {
+    expect(normalizeApiUrl('http://curator.example.com/apiary')).toBe(
+      'http://curator.example.com/apiary/api'
+    )
+  })
+
+  it('preserves a subpath deployment', () => {
+    expect(normalizeApiUrl('http://host.internal/curator')).toBe('http://host.internal/curator/api')
+  })
+})
+
+describe('webRootFromApiUrl', () => {
+  // The SPA root, where the Vue router and the served XPI live. Used by
+  // OPEN_ARTIST_PAGE and the self-update check — NOT the JSON API.
+  it('strips the /api suffix', () => {
+    expect(webRootFromApiUrl('http://curator.example.com/api')).toBe('http://curator.example.com')
+  })
+
+  it('accepts an instance root unchanged', () => {
+    expect(webRootFromApiUrl('http://curator.example.com')).toBe('http://curator.example.com')
+  })
+
+  it('agrees with normalizeApiUrl in both directions', () => {
+    for (const input of ['http://curator.example.com', 'http://curator.example.com/api']) {
+      expect(normalizeApiUrl(webRootFromApiUrl(input))).toBe(normalizeApiUrl(input))
+    }
+  })
+
+  it('preserves a subpath deployment', () => {
+    expect(webRootFromApiUrl('http://host.internal/curator/api')).toBe('http://host.internal/curator')
+  })
+
+  it('returns empty string for empty/nullish input', () => {
+    expect(webRootFromApiUrl('')).toBe('')
+    expect(webRootFromApiUrl(null)).toBe('')
+  })
+})
diff --git a/extension/test/version.spec.js b/extension/test/version.spec.js
new file mode 100644
index 0000000..f5cdf59
--- /dev/null
+++ b/extension/test/version.spec.js
@@ -0,0 +1,71 @@
+import { describe, it, expect } from 'vitest'
+import { readFileSync } from 'node:fs'
+import { fileURLToPath } from 'node:url'
+import path from 'node:path'
+
+const EXT_DIR = path.join(path.dirname(fileURLToPath(import.meta.url)), '..')
+const read = (name) => JSON.parse(readFileSync(path.join(EXT_DIR, name), 'utf8'))
+
+describe('extension version consistency', () => {
+  // Duplicates check (1) of ci.yml's extension-version job, deliberately.
+  // That job is the gate that can't be bypassed; this spec is the one that
+  // fails in a second on the developer's own CI lane with a readable diff.
+  // The two version strings feed different systems and nothing else reconciles
+  // them:
+  //   manifest.json  -> what `web-ext sign` signs, so what Firefox installs
+  //                     (package.json is in --ignore-files, not in the XPI)
+  //   package.json   -> build.yml's AMO cache key, the ext-<version> release
+  //                     tag, the XPI filename, and therefore the version
+  //                     /api/extension/manifest reports to the update prompt
+  it('keeps manifest.json and package.json in lockstep', () => {
+    const manifest = read('manifest.json')
+    const pkg = read('package.json')
+    expect(manifest.version).toBe(pkg.version)
+  })
+
+  it('uses a plain dotted numeric version AMO will accept', () => {
+    // AMO rejects exotic version strings, and build.yml embeds this value in a
+    // release tag and a filename — so anything needing escaping breaks the
+    // publish path rather than the extension.
+    expect(read('package.json').version).toMatch(/^\d+(\.\d+)*$/)
+  })
+
+  it('declares manifest v3', () => {
+    expect(read('manifest.json').manifest_version).toBe(3)
+  })
+
+  it('never lets the CI guard ignore a file that actually ships', () => {
+    // ci.yml's extension-version job skips its bump check for paths it deems
+    // non-shipping. If it excludes something web-ext DOES package, a real
+    // change to shipped code passes the guard unnoticed — precisely the
+    // silent-stale-ship the guard exists to stop. The reverse drift (guard
+    // stricter than web-ext) only costs a needless bump, so it isn't asserted.
+    const ci = readFileSync(path.join(EXT_DIR, '..', '.forgejo', 'workflows', 'ci.yml'), 'utf8')
+    const lint = read('package.json').scripts.lint
+    const after = lint.split('--ignore-files')[1] ?? ''
+    const ignored = new Set(
+      after
+        .split(/\s+/)
+        .filter((tok) => tok && !tok.startsWith('--'))
+        .map((tok) => tok.replace(/^["']|["']$/g, ''))
+    )
+    expect(ignored.size, 'parsed --ignore-files from the lint script').toBeGreaterThan(0)
+
+    const guarded = [...ci.matchAll(/:\(exclude\)extension\/(\S+?)'/g)].map((m) => m[1])
+    expect(guarded.length, 'parsed :(exclude) entries from ci.yml').toBeGreaterThan(0)
+    for (const entry of guarded) {
+      expect(ignored, `ci.yml excludes "${entry}" but web-ext packages it`).toContain(entry)
+    }
+  })
+
+  it('lists every background script that exists, in dependency order', () => {
+    // url.js must load BEFORE api.js: api.js calls normalizeApiUrl at
+    // init()-time, and these are classic scripts sharing one scope, so a
+    // reordering here is a runtime ReferenceError with no build-time signal.
+    const scripts = read('manifest.json').background.scripts
+    for (const rel of scripts) {
+      expect(() => readFileSync(path.join(EXT_DIR, rel)), `missing ${rel}`).not.toThrow()
+    }
+    expect(scripts.indexOf('lib/url.js')).toBeLessThan(scripts.indexOf('lib/api.js'))
+  })
+})
diff --git a/extension/vitest.config.js b/extension/vitest.config.js
new file mode 100644
index 0000000..a6f405f
--- /dev/null
+++ b/extension/vitest.config.js
@@ -0,0 +1,13 @@
+import { defineConfig } from 'vitest/config'
+
+// Mirrors frontend/vitest.config.js, minus the Vue plugin — the extension has
+// no SFCs and mounts nothing. Pure-logic specs only, so `node` is enough; the
+// libs under test are deliberately the ones with no browser-API surface (see
+// test/helpers/loadLib.js).
+export default defineConfig({
+  test: {
+    environment: 'node',
+    include: ['test/**/*.spec.js'],
+    passWithNoTests: true
+  }
+})