Merge pull request #2 from ribeiro-rodrigo/feat/#1-support-pulling-de…

…pendencies

Feat/#1 support pulling dependencies

README.md

@@ -56,6 +56,12 @@ container.Init(func(person Person){
 ```
 The Init method initializes the container and builds the dependency tree.
 
+The Lookup method is an alternative to the Init method. Lookup lets you search for dependencies and initialize the container automatically.
+
+```go
+person := cronos.Lookup(container, Person{})
+```
+
 ### Injecting Dependencies
 
 Dependencies must be injected through constructor functions

cronos.go

@@ -12,6 +12,7 @@ type key struct {
 }
 
 type Cronos struct {
+	initialized bool
 	cache
 }
 
@@ -28,24 +29,31 @@ type cache struct {
 // New - initializes the dependency injection container
 func New() Cronos {
 	return Cronos{
-		cache{
+		cache: cache{
 			components:    map[key]component{},
 			constructors:  map[key]constructor{},
 			options:       OptionsList{},
 			notSingletons: map[key]bool{},
 		},
+		initialized: false,
 	}
 }
 
 func (cronos *Cronos) proccessOptions() {
 
+	if cronos.initialized {
+		return
+	}
+
 	sort.Sort(cronos.cache.options)
 
 	for i := 0; i < len(cronos.cache.options); i++ {
 		op := cronos.cache.options[i]
 		task := op.task
 		task(op.key, cronos)
 	}
+
+	cronos.initialized = true
 }
 
 func (cronos *Cronos) invokeConstructor(constructor constructor, args []reflect.Type) (returns []reflect.Value) {
@@ -160,8 +168,13 @@ func (cronos *Cronos) Fetch(typed reflect.Type) interface{} {
 
 // Init - initializes the dependency injection container
 func (cronos *Cronos) Init(initFunc constructor) {
-
 	cronos.proccessOptions()
 	args := cronos.getArgs(initFunc)
 	cronos.invokeConstructor(initFunc, args)
 }
+
+func Lookup[T interface{}](container Cronos, typed T) T {
+	container.proccessOptions()
+	typec := reflect.TypeOf(typed)
+	return container.Fetch(typec).(T)
+}

cronos_test.go

@@ -347,3 +347,35 @@ func TestConstructorNotFunction(t *testing.T) {
 
 	assert.Panics(t, func() { container.Register(person{}) })
 }
+
+func TestLookup(t *testing.T) {
+	type id struct{ number string }
+
+	type employer struct{ id }
+
+	type worker struct{ id }
+
+	newID := func() id {
+		return id{number: uuidGenerator()}
+	}
+
+	newEmployer := func(id id) employer {
+		return employer{id}
+	}
+
+	newWorker := func(id id) worker {
+		return worker{id}
+	}
+
+	container := New()
+
+	container.Register(newEmployer)
+	container.Register(newWorker)
+	container.Register(newID, Singleton(false))
+
+	instanceWorker := Lookup(container, worker{})
+	instanceEmployer := Lookup(container, employer{})
+	if instanceWorker.id.number == instanceEmployer.id.number {
+		t.Error()
+	}
+}

go.mod

@@ -1,5 +1,11 @@
 module github.com/ribeiro-rodrigo/cronos
 
-go 1.14
+go 1.18
 
 require github.com/stretchr/testify v1.5.1
+
+require (
+	github.com/davecgh/go-spew v1.1.0 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v2 v2.2.2 // indirect
+)

go.sum

@@ -2,10 +2,10 @@ github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.5.1 h1:nOGnQDM7FYENwehXlg/kFVnos3rEvtKTjRvOWSzb6H4=
 github.com/stretchr/testify v1.5.1/go.mod h1:5W2xD1RspED5o8YsWQXVCued0rvSQ+mT+I5cxcmMvtA=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2 h1:ZCJp+EgiOT7lHqUV2J862kp8Qj64Jo6az82+3Td9dZw=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=