pluginsdk/plugin/wasmguest/testdata/capfixture/registration.go

// Package main is a NEGATIVE build fixture: its Register hook reaches a host
// capability (a db.* call) at describe time, which is illegal — DESCRIBE runs
// with no live host. `ninja plugin build` must surface an actionable error
// naming the offending call rather than hanging or crashing.
package main

import (
	"context"
	"database/sql"
	"fmt"

	// Registers the "bnwasm" database/sql driver (its init runs sql.Register).
	_ "git.dev.alexdunmow.com/block/pluginsdk/plugin/wasmguest/bnwasm"

	"git.dev.alexdunmow.com/block/pluginsdk/blocks"
	"git.dev.alexdunmow.com/block/pluginsdk/plugin"
	"git.dev.alexdunmow.com/block/pluginsdk/templates"
)

var Registration = plugin.PluginRegistration{
	Name:    "capfixture",
	Version: "0.0.1",
	Register: func(_ templates.TemplateRegistry, _ blocks.BlockRegistry) error {
		// Illegal describe-time capability use: query the host DB from
		// Register. Over the packer's failing host stub this returns an error
		// naming "db.query".
		db, err := sql.Open("bnwasm", "")
		if err != nil {
			return err
		}
		defer func() { _ = db.Close() }()
		var n int
		if err := db.QueryRowContext(context.Background(), "SELECT 1").Scan(&n); err != nil {
			return fmt.Errorf("describe-time db probe: %w", err)
		}
		return nil
	},
}