fix(functions): edge-runtime template offline bootstrap (#45570)

[ChrisJr404]

What

The edge-runtime entrypoint that supabase start writes into /root/index.ts (embedded from internal/functions/serve/templates/main.ts) starts with two remote imports:

import { STATUS_CODE, STATUS_TEXT } from "https://deno.land/std/http/status.ts";
import * as posix from "https://deno.land/std/path/posix/mod.ts";

Deno's graph builder resolves these every time the worker boots, so the runtime container fails to come up when the host has no network access.

Reported in supabase/supabase#45570:

error: TypeError: error sending request from 127.0.0.1:50932 for https://deno.land/std/http/status.ts (resolved to 2606:50c0:8000::153:443): client error (Connect): tcp connect error: Network is unreachable (os error 101): Network is unreachable (os error 101)
    at file:///root/index.ts:1:42

Why this happens

The image is supabase/edge-runtime:vX.Y.Z (pulled, not built here), and index.ts is materialised on each container start via the embedded template — there is no build-time deno cache step we can hook into to pre-warm the module graph for these URLs. Pinning to JSR hits the same wall: jsr: specifiers also require a registry round-trip on first use unless previously cached.

Fix

Inline the very small std surface this template actually depends on and drop the remote imports. Concretely:

Was	Now
STATUS_CODE.{OK,Unauthorized,NotFound,InternalServerError,ServiceUnavailable} from https://deno.land/std/http/status.ts	local STATUS_CODE const with the same five numeric values
STATUS_TEXT[STATUS_CODE.InternalServerError] from the same module	local STATUS_TEXT record with the same five reason phrases
posix.{dirname,join,toFileUrl} from https://deno.land/std/path/posix/mod.ts	local posix object with the same three helpers

The posix shim's outputs were cross-checked against node:path.posix for the path shapes this template constructs (/supabase/functions/<name>/index.ts, package-json discovery joins, absolute-to-file:// conversion). STATUS_TEXT reason phrases match RFC 9110.

This is the smallest viable diff that makes offline boot work — no Dockerfile changes, no new //go:embed plumbing, no surrounding refactor.

The jsr:@panva/jose@6 import on line 1 is unaffected: edge-runtime images already ship that module pre-cached (it has been in this template since #4721), which is why JWT verification works offline today and the std imports are the only blocker.

Regression test

Added TestMainTemplateNoRemoteImports in internal/functions/serve/serve_test.go. It scans the embedded template for https://deno.land/, http://deno.land/, https://esm.sh/, https://cdn.jsdelivr.net/, and https://unpkg.com/ and fails if any reappear. If anyone re-introduces a bare URL import here, the test catches it before the next offline-start regression.

Verification

• go build ./... clean
• go test ./internal/functions/... all pass (incl. existing TestServeCommand, TestServeFunctions, and the new pin)
• go vet ./... clean

Closes supabase/supabase#45570