feat: Full sub-path hosting support (BASE_URL with path)

[3rg0n]

Summary

• Fixes Support hosting Fider under a URL sub-path (e.g., example.com/feedback/) #1453: Adds comprehensive sub-path hosting support so Fider can be hosted at e.g. example.com/feedback/ behind a reverse proxy.
• Fixes Support relative path (e.g. example.com/feedback) #1298: Adds comprehensive sub-path hosting support so Fider can be hosted at e.g. example.com/feedback/ behind a reverse proxy.
• Depends on fix: Context.BaseURL() returns full BASE_URL in single-host mode #1454 (includes that commit): The core Context.BaseURL() fix that preserves the path component from BASE_URL.
• Adds a basePath() frontend utility (in navigator.ts) that extracts the path portion from Fider.settings.baseURL for use in href attributes and navigation.
• Updates the http service's fetch() wrapper to automatically prepend the base path to all root-relative API calls (/api/v1/..., /_api/...).
• Fixes navigator.goHome(), goTo(), and replaceState() to respect the base path.
• Updates all hardcoded root-relative href attributes across 15+ React components.
• Updates all hardcoded c.Redirect("/...") calls in 5 Go handler/middleware files to use c.BaseURL().
• Updates views/index.html Atom feed <link> tags to use the template baseURL variable.

Files changed (24 total)

Backend (Go):

• app/handlers/oauth.go — 3 redirects fixed
• app/handlers/post.go — 1 redirect fixed
• app/handlers/signin.go — 1 redirect fixed
• app/handlers/signup.go — 1 redirect fixed
• app/middlewares/tenant.go — 3 redirects fixed

Frontend services:

• public/services/navigator.ts — New basePath() utility, fixed goHome/goTo/replaceState
• public/services/http.ts — Auto-prepend base path to fetch URLs
• public/services/index.ts — Re-export basePath

Frontend components (href fixes):

• public/components/Header.tsx
• public/components/UserMenu.tsx
• public/components/ReadOnlyNotice.tsx
• public/components/common/Legal.tsx
• public/pages/Administration/components/SideMenu.tsx (12 links)
• public/pages/Administration/pages/Export.page.tsx
• public/pages/Administration/pages/GeneralSettings.page.tsx
• public/pages/Administration/pages/ManageBilling.page.tsx
• public/pages/Administration/pages/ContentModeration.page.tsx
• public/pages/Home/Home.page.tsx
• public/pages/Home/components/ShareFeedback.tsx
• public/pages/SignIn/CompleteSignInProfile.page.tsx
• public/pages/SignIn/LoginEmailSent.page.tsx
• commercial/components/ModerationIndicator.tsx
• commercial/pages/Administration/ContentModeration.page.tsx

Templates:

• views/index.html — Atom feed link hrefs

Test plan

• All 5 BaseURL unit tests pass
• go vet passes on changed Go packages
• Deploy with BASE_URL=https://example.com/feedback behind a reverse proxy
• Verify all navigation links include /feedback prefix
• Verify API calls (create/delete/vote on posts) go to /feedback/api/v1/...
• Verify sign-in/sign-out redirects go to /feedback/ not /
• Verify admin panel links work under the sub-path

🤖 Generated with Claude Code

[mattwoberts]

Thanks for this — sub-path hosting is a useful feature. A few things to address before this can merge.

1. Root-level file bloat

8 test infrastructure files have been added to the repo root: TESTING.md, TEST-README.md, TEST-SCENARIOS.md, QUICK-TEST.md, docker-compose-test.yml, Caddyfile.test, setup-hosts.sh, setup-hosts.ps1. These should be removed from this PR entirely.

2. Missed components — still broken under sub-path hosting

The manual basePath() approach missed several files that still have bare root-relative hrefs:

File	Line	Broken href
public/pages/Home/components/ListPosts.tsx	30	href={`/posts/${...}`}
public/pages/Home/components/ListPosts.tsx	84	href={`/posts/${...}`}
public/components/NotificationIndicator.tsx	17	href={`/notifications/${...}`}
public/components/ShowPostResponse.tsx	51	href={`/posts/${...}`}
public/pages/MyNotifications/MyNotifications.page.tsx	41	href={`/notifications/${...}`}
public/components/ShowTag.tsx	37	href={`/?tags=${...}`}

These are the exact bugs that prove the core concern below.

3. Fragile pattern — future bugs guaranteed

The fundamental problem with this PR is that every developer must remember to call basePath() on every href and every c.Redirect(). The PR itself missing 6 components demonstrates this won't scale. A few suggestions:

Frontend:

a) Create a resolveHref() utility in navigator.ts that centralises the basePath-prepending logic (it's currently duplicated between navigator.goTo(), http.ts's resolveUrl(), and every call site).

b) Auto-resolve inside Button and Dropdown.ListItem — both components render <a href={props.href}> and pass the href straight through (Button.tsx:55, Dropdown.tsx:28). If they called resolveHref() internally, callers wouldn't need to think about it. The idempotency guard (!href.startsWith(bp)) makes double-application harmless.

c) Create a <Link> component — a thin wrapper around <a> that calls resolveHref(). Replace all bare <a href="/..."> with <Link href="/...">. Developers write natural paths, basePath is handled automatically.

d) Add an ESLint rule to flag hardcoded root-relative href attributes in JSX (both string literals like href="/admin" and template literals like href={`/posts/${id}`}). This can be a local rule in eslint-rules/ using --rulesdir — zero new dependencies. The lint rule is the safety net; the components above are the primary defense.

Backend (Go):

e) Add a c.RedirectTo(path) helper on Context that does c.Redirect(c.BasePath() + path). Replace all 9 manual c.Redirect(c.BasePath() + "/...") calls. Same principle — developers write natural paths, the helper handles the prefix.

4. Duplicated basePath logic

basePath() extraction appears in three places with slightly different implementations:

• navigator.ts basePath()
• http.ts resolveUrl() (inline)
• navigator.ts goTo() (inline)

These should be consolidated into one resolveHref() function.

---

[mattwoberts]

Hi - I added a comment that is basically the review :)

[3rg0n]

Thanks Matt, will get to it today and push the updates.

[3rg0n]

Hi @mattwoberts — thanks for the detailed review. Pushed fixes on top of the existing branch (not force-pushed, so your "viewed" state should still be intact). Here's a per-item mapping with commit SHAs.

First, a note on the merge: upstream had moved significantly since this PR was opened (Go 1.25 bump, commercial module removed, OAuth allowed-roles, zh-TW locale, DoS fix, etc.) and our branch modified a file that got deleted upstream (commercial/pages/Administration/ContentModeration.page.tsx), so the PR no longer applied cleanly. Merged upstream/main first (c75f6546) so the reviewable diff is against the current main. Conflict resolutions:

• commercial/pages/Administration/ContentModeration.page.tsx — accepted upstream delete
• public/pages/Administration/pages/ContentModeration.page.tsx — took upstream's full implementation (our version was a stub pointing at the now-removed commercial module)
• public/pages/Administration/pages/ManageBilling.page.tsx — took upstream (our commercial-upgrade banner was obsolete since the licensing model was removed)

---

Item 1 — Root-level file bloat ✅

Commit: 343cf320 — removed all 8 files (TESTING.md, TEST-README.md, TEST-SCENARIOS.md, QUICK-TEST.md, docker-compose-test.yml, Caddyfile.test, setup-hosts.sh, setup-hosts.ps1).

Item 2 — Missed components ✅

Commit: 8a6160f2 — all 6 flagged hrefs migrated to the new <Link> component introduced in the same commit (item 3c). Fixing them via the primitive rather than scattering basePath() calls addresses your scalability concern directly.

Item 3a + 4 — Consolidate basePath logic, resolveHref() utility ✅

Commit: 02140d94 — single resolveHref() in public/services/navigator.ts. Replaced the three duplicates:

• navigator.basePath() call site inside goTo() (now resolveHref(url))
• navigator.goTo() inline logic (now uses resolveHref())
• http.ts resolveUrl() (removed, uses resolveHref())

Also fixed a bare window.location.href = "/signin?redirect=..." in http.ts (401 re-auth path) that was broken under sub-path hosting — now goes through resolveHref().

The idempotency guard (!href.startsWith(bp)) means any remaining ${basePath()}/... call sites continue to work without a double-prefix, so this change was safe to land independently of call-site cleanup.

Item 3b — Auto-resolve in Button and Dropdown.ListItem ✅

Commit: 01dcc089 — both components now run href through resolveHref() internally.

Item 3c — <Link> component ✅

Commit: 8a6160f2 — public/components/common/Link.tsx. Thin wrapper around <a> that runs href through resolveHref(). Used for all 6 flagged sites.

Rationale for <Link> over a bare basePath() call at each site: the PR having missed 6 sites across 5 components is direct evidence that a "remember to call basePath()" convention does not scale. A wrapper component inverts the default — correctness is the path of least resistance. The ESLint rule (item 3d) is the safety net enforcing this.

Item 3d — ESLint rule ✅

Commits: fb3a4f13 + 6d59f411 + f94cd695 — eslint-rules/no-bare-root-href.js. Flags bare root-relative hrefs in JSX (string literals and template literals). Exempts <Link>, <Button>, Dropdown.ListItem, ${basePath()}/... templates, absolute URLs, fragments, etc.

Rationale for --rulesdir local rule vs. an ESLint plugin package: you explicitly preferred no new dependencies, and a 60-line rule doesn't warrant a publish story or a package bump. Wired into make lint-ui via --rulesdir eslint-rules.

Scope: the rule catches JSX href attributes. It doesn't cover window.location.href = "/..." patterns (those aren't JSX). One such case was introduced by the upstream merge in ContentModeration.page.tsx — fixed that by switching to navigator.goTo() (which uses resolveHref() internally).

Item 3e — c.RedirectTo(path) helper ✅

Commit: 85c995f2 — new helper on web.Context in app/pkg/web/context.go:

func (c *Context) RedirectTo(path string) error {
    return c.Redirect(c.BasePath() + path)
}

Migrated 8 c.Redirect(c.BasePath() + "/...") sites across app/handlers/oauth.go, signin.go, signup.go, and app/middlewares/tenant.go.

Also fixed 3 bare c.Redirect("/...") sites that arrived with the upstream OAuth allowed-roles work (/access-denied in oauth.go, /signin and /signin?redirect=... in middlewares/user.go) — these were sub-path hosting bugs on their own.

---

Tests added (commit 81176366)

• public/services/navigator.spec.ts — 10 tests for resolveHref(): domain-root pass-through, sub-path prefix, idempotency, trailing-slash handling, pass-through for absolute URLs/fragments/mailto/empty/relative, malformed-baseURL fallback.
• public/components/common/Link.spec.tsx — 3 tests for <Link>: bare href at root, prefix insertion under sub-path, passthrough of className/target/rel.

Test results — full make test and make lint locally

Ran the contributor test suite per CONTRIBUTING.md inside a Linux container (golang:1.25-bookworm + Node 22) against Podman-hosted Postgres/MinIO/MailHog (the docker-compose.yml services). My Windows Go toolchain can't link rogchap.com/v8go for the SSR runtime, so the container approach was the cleanest way to mirror CI locally:

• make lint: ✅ clean. 0 errors. 2 pre-existing warnings in public/services/fider.ts (unrelated @typescript-eslint/no-non-null-assertion).
• make test-server: ✅ all 34 Go test packages pass (app/cmd, app/handlers, app/handlers/apiv1, app/middlewares, app/pkg/web, app/services/email/smtp, app/services/oauth, app/services/sqlstore/postgres, app/tasks, etc.).
• make test-ui: ✅ 12 Jest suites, 140/140 tests pass (includes the two new specs above).

Re-requesting review. Happy to iterate further.