feat(01-01): boot hello app and dispatch greeter:hello
- Add party plugin registry with Register-before-Boot activation - Add backpack, compass, bonfire, and pact capability interfaces - Add examples/hello with two compiled plugin modules
This commit is contained in:
Jakub Zych
195
party/registry.go
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195
party/registry.go
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@@ -0,0 +1,195 @@
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package party
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import (
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"fmt"
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"strings"
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"sync"
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"git.golem15.com/golem15/summercms/backpack"
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)
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// Plugin is the required descriptor every compiled plugin implements.
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type Plugin interface {
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ID() string
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Requires() []string
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Register(app *backpack.App) error
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Boot(app *backpack.App) error
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}
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var (
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mu sync.Mutex
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plugins []Plugin
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)
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// Register appends a plugin to the process-wide registry. Plugins call this
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// from init() after a blank import; Activate selects and orders them.
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func Register(p Plugin) {
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if p == nil {
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return
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}
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mu.Lock()
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defer mu.Unlock()
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plugins = append(plugins, p)
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}
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func snapshot() []Plugin {
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mu.Lock()
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defer mu.Unlock()
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out := make([]Plugin, len(plugins))
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copy(out, plugins)
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return out
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}
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// Activate resolves ids in manifest order, topologically sorts Requires(),
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// then runs every Register before any Boot.
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func Activate(app *backpack.App, ids []string) ([]Plugin, error) {
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if app == nil {
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return nil, fmt.Errorf("party: app is nil")
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}
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return activate(snapshot(), app, ids)
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}
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func activate(registered []Plugin, app *backpack.App, ids []string) ([]Plugin, error) {
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byID := make(map[string]Plugin, len(registered))
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for _, p := range registered {
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if p == nil {
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continue
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}
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id := p.ID()
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if id == "" {
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return nil, fmt.Errorf("party: registered plugin has empty id")
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}
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if _, exists := byID[id]; exists {
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return nil, fmt.Errorf("party: duplicate plugin id %q", id)
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}
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byID[id] = p
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}
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seen := make(map[string]struct{}, len(ids))
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selected := make([]Plugin, 0, len(ids))
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index := make(map[string]int, len(ids))
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for _, id := range ids {
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if id == "" {
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return nil, fmt.Errorf("party: empty plugin id in manifest")
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}
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if _, dup := seen[id]; dup {
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return nil, fmt.Errorf("party: duplicate plugin id %q", id)
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}
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seen[id] = struct{}{}
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p, ok := byID[id]
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if !ok {
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return nil, fmt.Errorf("party: plugin %q is not registered", id)
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}
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index[id] = len(selected)
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selected = append(selected, p)
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}
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for _, p := range selected {
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for _, req := range p.Requires() {
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if _, ok := seen[req]; !ok {
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return nil, fmt.Errorf("party: plugin %q requires %q, which is not registered", p.ID(), req)
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}
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}
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}
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ordered, err := topoSort(selected, index)
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if err != nil {
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return nil, err
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}
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for _, p := range ordered {
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if err := p.Register(app); err != nil {
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return nil, fmt.Errorf("party: register %s: %w", p.ID(), err)
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}
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}
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for _, p := range ordered {
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if err := p.Boot(app); err != nil {
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return nil, fmt.Errorf("party: boot %s: %w", p.ID(), err)
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}
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}
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return ordered, nil
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}
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func topoSort(plugins []Plugin, index map[string]int) ([]Plugin, error) {
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byID := make(map[string]Plugin, len(plugins))
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indeg := make(map[string]int, len(plugins))
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dependents := make(map[string][]string, len(plugins))
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for _, p := range plugins {
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byID[p.ID()] = p
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indeg[p.ID()] = 0
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}
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for _, p := range plugins {
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seenReq := make(map[string]struct{})
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for _, req := range p.Requires() {
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if _, ok := seenReq[req]; ok {
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continue
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}
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seenReq[req] = struct{}{}
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if _, ok := byID[req]; !ok {
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continue
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}
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indeg[p.ID()]++
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dependents[req] = append(dependents[req], p.ID())
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}
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}
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ready := make([]string, 0, len(plugins))
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for _, p := range plugins {
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if indeg[p.ID()] == 0 {
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ready = append(ready, p.ID())
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}
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}
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out := make([]Plugin, 0, len(plugins))
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for len(ready) > 0 {
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id := ready[0]
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ready = ready[1:]
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out = append(out, byID[id])
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next := append([]string(nil), dependents[id]...)
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sortByIndex(next, index)
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for _, dep := range next {
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indeg[dep]--
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if indeg[dep] == 0 {
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ready = insertByIndex(ready, dep, index)
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}
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}
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}
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if len(out) != len(plugins) {
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leftover := make([]string, 0)
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done := make(map[string]struct{}, len(out))
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for _, p := range out {
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done[p.ID()] = struct{}{}
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}
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for _, p := range plugins {
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if _, ok := done[p.ID()]; !ok {
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leftover = append(leftover, p.ID())
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}
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}
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return nil, fmt.Errorf("party: dependency cycle involving %s", strings.Join(leftover, ", "))
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}
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return out, nil
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}
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func sortByIndex(ids []string, index map[string]int) {
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for i := 1; i < len(ids); i++ {
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j := i
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for j > 0 && index[ids[j]] < index[ids[j-1]] {
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ids[j], ids[j-1] = ids[j-1], ids[j]
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j--
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}
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}
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}
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func insertByIndex(ready []string, id string, index map[string]int) []string {
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at := len(ready)
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for i, existing := range ready {
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if index[id] < index[existing] {
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at = i
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break
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}
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}
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ready = append(ready, "")
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copy(ready[at+1:], ready[at:])
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ready[at] = id
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return ready
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}
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56
party/registry_test.go
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56
party/registry_test.go
Normal file
@@ -0,0 +1,56 @@
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package party
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import (
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"strings"
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"testing"
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"git.golem15.com/golem15/summercms/backpack"
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"git.golem15.com/golem15/summercms/compass"
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)
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type tracePlugin struct {
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id string
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req []string
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log *[]string
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}
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func (p *tracePlugin) ID() string { return p.id }
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func (p *tracePlugin) Requires() []string { return p.req }
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func (p *tracePlugin) Register(*backpack.App) error {
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*p.log = append(*p.log, p.id+":register")
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return nil
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}
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func (p *tracePlugin) Boot(*backpack.App) error {
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*p.log = append(*p.log, p.id+":boot")
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return nil
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}
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func TestActivateRunsAllRegisterBeforeAnyBoot(t *testing.T) {
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var log []string
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hello := &tracePlugin{id: "golem15.hello", log: &log}
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greeter := &tracePlugin{id: "golem15.greeter", req: []string{"golem15.hello"}, log: &log}
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app := backpack.New(&compass.Config{})
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got, err := activate([]Plugin{greeter, hello}, app, []string{"golem15.greeter", "golem15.hello"})
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if err != nil {
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t.Fatalf("activate: %v", err)
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}
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if len(got) != 2 {
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t.Fatalf("got %d plugins, want 2", len(got))
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}
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if got[0].ID() != "golem15.hello" || got[1].ID() != "golem15.greeter" {
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t.Fatalf("order = %s, %s", got[0].ID(), got[1].ID())
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}
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want := []string{
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"golem15.hello:register",
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"golem15.greeter:register",
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"golem15.hello:boot",
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"golem15.greeter:boot",
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}
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if strings.Join(log, ",") != strings.Join(want, ",") {
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t.Fatalf("lifecycle = %v, want %v", log, want)
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}
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}
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