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theplant · Jun 21, 2024 · b7debd8 · b7debd8
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diff --git a/LICENSE b/LICENSE
@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2024-present The Plant
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
diff --git a/README.md b/README.md
@@ -0,0 +1,167 @@
+# inject
+
+The `inject` package is inspired by [codecangsta/inject](https://github.com/codegangsta/inject) and provides simplified public methods for dependency injection in Go.
+
+## Features
+
+- `Provide`: Used to provide dependencies through a function.
+- `Invoke`: Used to resolve dependencies and invoke a function with them.
+- `Resolve`: Used to resolve a dependency by its type.
+- `Apply`: Used to apply dependencies to a struct.
+- `SetParent`: Used to set the parent injector.
+- Thread safety ensured
+- Supports injection through the `inject` tag of struct fields
+
+## Usage
+
+Here's an example of how to use the `inject` package:
+
+```go
+package inject_test
+
+import (
+	"fmt"
+
+	"github.com/theplant/inject"
+)
+
+// Define interfaces and implementations
+type Printer interface {
+	Print() string
+}
+
+type SimplePrinter struct{}
+
+func (p *SimplePrinter) Print() string {
+	return "Printing document"
+}
+
+// New type definition
+type DocumentDescription string
+
+type Document struct {
+	Injector *inject.Injector `inject:""` // Injector will be provided by default, so you can also get it if needed
+
+	ID          string              // Not injected
+	Description DocumentDescription `inject:""`         // Exported non-optional field
+	Printer     Printer             `inject:""`         // Exported non-optional field
+	Size        int64               `inject:"optional"` // Exported optional field
+	page        int                 `inject:""`         // Unexported non-optional field
+	name        string              `inject:"optional"` // Unexported optional field
+}
+
+func ExampleInjector() {
+	inj := inject.New()
+
+	// Provide dependencies
+	if err := inj.Provide(
+		func() Printer {
+			return &SimplePrinter{}
+		},
+		func() string {
+			return "A simple string"
+		},
+		func() DocumentDescription {
+			return "A document description"
+		},
+		func() int {
+			return 42
+		},
+	); err != nil {
+		panic(err)
+	}
+
+	{
+		// Resolve dependencies
+		var printer Printer
+		if err := inj.Resolve(&printer); err != nil {
+			panic(err)
+		}
+		fmt.Println("Resolved printer:", printer.Print())
+	}
+
+	printDoc := func(doc *Document) {
+		fmt.Printf("Document id: %q\n", doc.ID)
+		fmt.Printf("Document description: %q\n", doc.Description)
+		fmt.Printf("Document printer: %q\n", doc.Printer.Print())
+		fmt.Printf("Document size: %d\n", doc.Size)
+		fmt.Printf("Document page: %d\n", doc.page)
+		fmt.Printf("Document name: %q\n", doc.name)
+	}
+
+	fmt.Println("-------")
+
+	{
+		// Invoke a function
+		results, err := inj.Invoke(func(printer Printer) *Document {
+			return &Document{
+				// This value will be retained as it is not tagged with `inject`, despite string being provided
+				ID: "idInvoked",
+				// This value will be overridden since it is tagged with `inject` and DocumentDescription is provided
+				Description: "DescriptionInvoked",
+				// This value will be overridden with the same value since it is tagged with `inject` and Printer is provided
+				Printer: printer,
+				// This value will be retained since it is tagged with `inject:"optional"` and int64 is not provided
+				Size: 100,
+			}
+		})
+		if err != nil {
+			panic(err)
+		}
+
+		printDoc(results[0].(*Document))
+	}
+
+	fmt.Println("-------")
+
+	{
+		// Apply dependencies to a struct instance
+		doc := &Document{}
+		if err := inj.Apply(doc); err != nil {
+			panic(err)
+		}
+
+		printDoc(doc)
+	}
+
+	fmt.Println("-------")
+
+	{
+		// Create a child injector and then apply dependencies to a struct instance
+		child := inject.New()
+		child.SetParent(inj)
+
+		doc := &Document{}
+		if err := child.Apply(doc); err != nil {
+			panic(err)
+		}
+
+		printDoc(doc)
+	}
+
+	// Output:
+	// Resolved printer: Printing document
+	// -------
+	// Document id: "idInvoked"
+	// Document description: "A document description"
+	// Document printer: "Printing document"
+	// Document size: 100
+	// Document page: 42
+	// Document name: "A simple string"
+	// -------
+	// Document id: ""
+	// Document description: "A document description"
+	// Document printer: "Printing document"
+	// Document size: 0
+	// Document page: 42
+	// Document name: "A simple string"
+	// -------
+	// Document id: ""
+	// Document description: "A document description"
+	// Document printer: "Printing document"
+	// Document size: 0
+	// Document page: 42
+	// Document name: "A simple string"
+}
+
+```
diff --git a/example_test.go b/example_test.go
@@ -0,0 +1,146 @@
+package inject_test
+
+import (
+	"fmt"
+
+	"github.com/theplant/inject"
+)
+
+// Define interfaces and implementations
+type Printer interface {
+	Print() string
+}
+
+type SimplePrinter struct{}
+
+func (p *SimplePrinter) Print() string {
+	return "Printing document"
+}
+
+// New type definition
+type DocumentDescription string
+
+type Document struct {
+	Injector *inject.Injector `inject:""` // Injector will be provided by default, so you can also get it if needed
+
+	ID          string              // Not injected
+	Description DocumentDescription `inject:""`         // Exported non-optional field
+	Printer     Printer             `inject:""`         // Exported non-optional field
+	Size        int64               `inject:"optional"` // Exported optional field
+	page        int                 `inject:""`         // Unexported non-optional field
+	name        string              `inject:"optional"` // Unexported optional field
+}
+
+func ExampleInjector() {
+	inj := inject.New()
+
+	// Provide dependencies
+	if err := inj.Provide(
+		func() Printer {
+			return &SimplePrinter{}
+		},
+		func() string {
+			return "A simple string"
+		},
+		func() DocumentDescription {
+			return "A document description"
+		},
+		func() int {
+			return 42
+		},
+	); err != nil {
+		panic(err)
+	}
+
+	{
+		// Resolve dependencies
+		var printer Printer
+		if err := inj.Resolve(&printer); err != nil {
+			panic(err)
+		}
+		fmt.Println("Resolved printer:", printer.Print())
+	}
+
+	printDoc := func(doc *Document) {
+		fmt.Printf("Document id: %q\n", doc.ID)
+		fmt.Printf("Document description: %q\n", doc.Description)
+		fmt.Printf("Document printer: %q\n", doc.Printer.Print())
+		fmt.Printf("Document size: %d\n", doc.Size)
+		fmt.Printf("Document page: %d\n", doc.page)
+		fmt.Printf("Document name: %q\n", doc.name)
+	}
+
+	fmt.Println("-------")
+
+	{
+		// Invoke a function
+		results, err := inj.Invoke(func(printer Printer) *Document {
+			return &Document{
+				// This value will be retained as it is not tagged with `inject`, despite string being provided
+				ID: "idInvoked",
+				// This value will be overridden since it is tagged with `inject` and DocumentDescription is provided
+				Description: "DescriptionInvoked",
+				// This value will be overridden with the same value since it is tagged with `inject` and Printer is provided
+				Printer: printer,
+				// This value will be retained since it is tagged with `inject:"optional"` and int64 is not provided
+				Size: 100,
+			}
+		})
+		if err != nil {
+			panic(err)
+		}
+
+		printDoc(results[0].(*Document))
+	}
+
+	fmt.Println("-------")
+
+	{
+		// Apply dependencies to a struct instance
+		doc := &Document{}
+		if err := inj.Apply(doc); err != nil {
+			panic(err)
+		}
+
+		printDoc(doc)
+	}
+
+	fmt.Println("-------")
+
+	{
+		// Create a child injector and then apply dependencies to a struct instance
+		child := inject.New()
+		child.SetParent(inj)
+
+		doc := &Document{}
+		if err := child.Apply(doc); err != nil {
+			panic(err)
+		}
+
+		printDoc(doc)
+	}
+
+	// Output:
+	// Resolved printer: Printing document
+	// -------
+	// Document id: "idInvoked"
+	// Document description: "A document description"
+	// Document printer: "Printing document"
+	// Document size: 100
+	// Document page: 42
+	// Document name: "A simple string"
+	// -------
+	// Document id: ""
+	// Document description: "A document description"
+	// Document printer: "Printing document"
+	// Document size: 0
+	// Document page: 42
+	// Document name: "A simple string"
+	// -------
+	// Document id: ""
+	// Document description: "A document description"
+	// Document printer: "Printing document"
+	// Document size: 0
+	// Document page: 42
+	// Document name: "A simple string"
+}
diff --git a/go.mod b/go.mod
@@ -0,0 +1,15 @@
+module github.com/theplant/inject
+
+go 1.22.3
+
+require (
+	github.com/pkg/errors v0.9.1
+	github.com/stretchr/testify v1.9.0
+	golang.org/x/sync v0.7.0
+)
+
+require (
+	github.com/davecgh/go-spew v1.1.1 // indirect
+	github.com/pmezard/go-difflib v1.0.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/go.sum b/go.sum
@@ -0,0 +1,14 @@
+github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
+github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pkg/errors v0.9.1 h1:FEBLx1zS214owpjy7qsBeixbURkuhQAwrK5UwLGTwt4=
+github.com/pkg/errors v0.9.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
+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/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
+golang.org/x/sync v0.7.0 h1:YsImfSBoP9QPYL0xyKJPq0gcaJdG3rInoqxTWbfQu9M=
+golang.org/x/sync v0.7.0/go.mod h1:Czt+wKu1gCyEFDUtn0jG5QVvpJ6rzVqr5aXyt9drQfk=
+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.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=