Merge pull request #3 from kovetskiy/master

add -init parameter

Author: kovetskiy

README.md

@@ -16,6 +16,8 @@ also you can get the pre-built binaries on [Releases](https://github.com/moznion
 Usage of gonstructor:
   -constructorTypes string
         [optional] comma-separated list of constructor types; it expects "allArgs" and "builder" (default "allArgs")
+  -init string
+        [optional] name of function to call on object after creating it
   -output string
         [optional] output file name (default "srcdir/<type>_gen.go")
   -type string
@@ -107,6 +109,42 @@ func (b *StructureBuilder) Build() *Structure {
 }
 ```
 
+### Call a initializer
+
+1. write a struct type with `go:generate`
+2. write a function that initializes internal fields
+3. pass its name to `-init` parameter
+
+e.g.
+
+```go
+//go:generate gonstructor --type=Structure -init construct
+type Structure struct {
+	foo        string
+	bar        io.Reader
+	Buz        chan interface{}
+	bufferSize int
+	buffer     chan []byte `gonstructor:"-"`
+}
+
+func (structure *Structure) construct() {
+	structure.buffer = make(chan []byte, structure.bufferSize)
+}
+```
+
+2. execute `go generate ./...`
+3. then `gonstructor` generates a buildr code
+
+e.g.
+
+```go
+func NewStructure(foo string, bar io.Reader, buz chan interface{}, bufferSize int) *Structure {
+        r := &Structure{foo: foo, bar: bar, Buz: buz, bufferSize: bufferSize}
+        r.construct()
+        return r
+}
+```
+
 ## How to ignore to contain a field in a constructor
 
 `gonstructor:"-"` supports that.
@@ -129,4 +167,3 @@ Binaries are built and uploaded by [goreleaser](https://goreleaser.com/). Please
 ## Author
 
 moznion (<moznion@gmail.com>)
-

cmd/gonstructor/gonstructor.go

@@ -26,6 +26,7 @@ var (
 	constructorTypes  = flag.String("constructorTypes", allArgsConstructorType, fmt.Sprintf(`[optional] comma-separated list of constructor types; it expects "%s" and "%s"`, allArgsConstructorType, builderConstructorType))
 	shouldShowVersion = flag.Bool("version", false, "[optional] show the version information")
 	withGetter        = flag.Bool("withGetter", false, "[optional] generate a constructor along with getter functions for each field")
+	initFunc          = flag.String("init", "", "[optional] name of function to call on object after creating it")
 )
 
 func main() {
@@ -82,11 +83,13 @@ func main() {
 			constructorGenerator = &constructor.AllArgsConstructorGenerator{
 				TypeName: *typeName,
 				Fields:   fields,
+				InitFunc: *initFunc,
 			}
 		case builderConstructorType:
 			constructorGenerator = &constructor.BuilderGenerator{
 				TypeName: *typeName,
 				Fields:   fields,
+				InitFunc: *initFunc,
 			}
 		default:
 			// unreachable, just in case

internal/constructor/all_args_constructor_generator.go

@@ -12,6 +12,7 @@ import (
 type AllArgsConstructorGenerator struct {
 	TypeName string
 	Fields   []*Field
+	InitFunc string
 }
 
 // Generate generates a constructor statement with all of arguments.
@@ -29,9 +30,25 @@ func (cg *AllArgsConstructorGenerator) Generate() g.Statement {
 
 	funcSignature = funcSignature.AddReturnTypes("*" + cg.TypeName)
 
-	return g.NewFunc(
+	retStructure := fmt.Sprintf("&%s{%s}", cg.TypeName, strings.Join(retStructureKeyValues, ","))
+
+	var stmts []g.Statement
+	if cg.InitFunc != "" {
+		stmts = []g.Statement{
+			g.NewRawStatementf("r := %s", retStructure),
+			g.NewRawStatementf("r.%s()", cg.InitFunc),
+			g.NewReturnStatement("r"),
+		}
+	} else {
+		stmts = []g.Statement{
+			g.NewReturnStatement(retStructure),
+		}
+	}
+
+	fn := g.NewFunc(
 		nil,
 		funcSignature,
-		g.NewReturnStatement(fmt.Sprintf("&%s{%s}", cg.TypeName, strings.Join(retStructureKeyValues, ","))),
+		stmts...,
 	)
+	return fn
 }

internal/constructor/builder_constructor_generator.go

@@ -12,6 +12,7 @@ import (
 type BuilderGenerator struct {
 	TypeName string
 	Fields   []*Field
+	InitFunc string
 }
 
 // Generate generates a builder statement.
@@ -51,11 +52,25 @@ func (cg *BuilderGenerator) Generate() g.Statement {
 		retStructureKeyValues = append(retStructureKeyValues, fmt.Sprintf("%s: b.%s", field.FieldName, toLowerCamel(field.FieldName)))
 	}
 
+	buildResult := fmt.Sprintf("&%s{%s}", cg.TypeName, strings.Join(retStructureKeyValues, ","))
+
+	var buildStmts []g.Statement
+	if cg.InitFunc != "" {
+		buildStmts = append(buildStmts, g.NewRawStatementf("r := %s", buildResult))
+		buildStmts = append(buildStmts, g.NewRawStatementf("r.%s()", cg.InitFunc))
+		buildStmts = append(buildStmts, g.NewReturnStatement("r"))
+	} else {
+		buildStmts = append(
+			buildStmts,
+			g.NewReturnStatement(buildResult),
+		)
+	}
+
 	buildFunc := g.NewFunc(
 		g.NewFuncReceiver("b", "*"+builderType),
 		g.NewFuncSignature("Build").
 			AddReturnTypes("*"+cg.TypeName),
-		g.NewReturnStatement(fmt.Sprintf("&%s{%s}", cg.TypeName, strings.Join(retStructureKeyValues, ","))),
+		buildStmts...,
 	)
 
 	stmt := g.NewRoot(builderStruct, builderConstructorFunc)

internal/test/structure.go

@@ -15,3 +15,14 @@ type ChildStructure struct {
 	structure *Structure
 	foobar    string
 }
+
+//go:generate sh -c "$(cd ./\"$(git rev-parse --show-cdup)\" || exit; pwd)/dist/gonstructor_test --type=StructureWithInit --constructorTypes=allArgs,builder --withGetter --init initialize"
+type StructureWithInit struct {
+	foo    string
+	status string      `gonstructor:"-"`
+	qux    interface{} `gonstructor:"-"`
+}
+
+func (structure *StructureWithInit) initialize() {
+	structure.status = "ok"
+}

internal/test/structure_test.go

@@ -55,3 +55,32 @@ func TestChildStructureAllArgsConstructor(t *testing.T) {
 	assert.EqualValues(t, structure, got.structure)
 	assert.EqualValues(t, givenString, got.foobar)
 }
+
+func TestStructureWithInitAllArgsConstructor(t *testing.T) {
+	givenString := "givenstr"
+
+	got := NewStructureWithInit(givenString)
+	assert.IsType(t, &StructureWithInit{}, got)
+
+	assert.EqualValues(t, givenString, got.foo)
+	assert.EqualValues(t, "ok", got.status)
+	assert.EqualValues(t, nil, got.qux)
+
+	// test for getters
+	assert.EqualValues(t, givenString, got.GetFoo())
+	assert.EqualValues(t, "ok", got.GetStatus())
+	assert.EqualValues(t, nil, got.GetQux())
+}
+
+func TestStructureWithInitBuilder(t *testing.T) {
+	givenString := "givenstr"
+
+	b := NewStructureWithInitBuilder()
+	got := b.Foo(givenString).
+		Build()
+	assert.IsType(t, &StructureWithInit{}, got)
+
+	assert.EqualValues(t, givenString, got.foo)
+	assert.EqualValues(t, "ok", got.status)
+	assert.EqualValues(t, nil, got.qux)
+}