Support namespace functions with aliases and defaults (magefile#183)

* support namespace funcs as aliases and defaults

fixes magefile#181

mage/main.go

@@ -377,7 +377,7 @@ type data struct {
 	DefaultError bool
 	Default      string
 	DefaultFunc  parse.Function
-	Aliases      map[string]string
+	Aliases      map[string]parse.Function
 }
 
 func goVersion(gocmd string) (string, error) {
@@ -529,13 +529,10 @@ func GenerateMainfile(path, cachedir string, info *parse.PkgInfo) error {
 	data := data{
 		Description: info.Description,
 		Funcs:       info.Funcs,
-		Default:     info.DefaultName,
 		DefaultFunc: info.DefaultFunc,
 		Aliases:     info.Aliases,
 	}
 
-	data.DefaultError = info.DefaultIsError
-
 	debug.Println("writing new file at", path)
 	if err := output.Execute(f, data); err != nil {
 		return fmt.Errorf("can't execute mainfile template: %v", err)

mage/main_test.go

@@ -740,11 +740,11 @@ func TestInvalidAlias(t *testing.T) {
 		Args:   []string{"co"},
 	}
 	code := Invoke(inv)
-	if code != 1 {
+	if code != 2 {
 		t.Errorf("expected to exit with code 1, but got %v", code)
 	}
 	actual := stderr.String()
-	expected := "Unknown target: \"co\"\n"
+	expected := "Unknown target specified: co\n"
 	if actual != expected {
 		t.Fatalf("expected %q, but got %q", expected, actual)
 	}
@@ -939,3 +939,20 @@ func TestNamespace(t *testing.T) {
 		t.Fatalf("expected %q, but got %q", expected, stdout.String())
 	}
 }
+
+func TestNamespaceDefault(t *testing.T) {
+	stdout := &bytes.Buffer{}
+	inv := Invocation{
+		Dir:    "./testdata/namespaces",
+		Stderr: ioutil.Discard,
+		Stdout: stdout,
+	}
+	code := Invoke(inv)
+	if code != 0 {
+		t.Fatalf("expected 0, but got %v", code)
+	}
+	expected := "hi!\n"
+	if stdout.String() != expected {
+		t.Fatalf("expected %q, but got %q", expected, stdout.String())
+	}
+}

mage/template.go

@@ -22,14 +22,14 @@ func main() {
 	// magefiles.
 	list := func() error {
 		{{with .Description}}fmt.Println(` + "`{{.}}\n`" + `){{end}}
-		{{- $default := .Default}}
+		{{- $default := .DefaultFunc}}
 		w := tabwriter.NewWriter(os.Stdout, 0, 4, 4, ' ', 0)
 		fmt.Println("Targets:")
 		{{- range .Funcs}}
-		fmt.Fprintln(w, "  {{lowerfirst .TemplateName}}{{if eq .Name $default}}*{{end}}\t" + {{printf "%q" .Synopsis}})
+		fmt.Fprintln(w, "  {{lowerfirst .TemplateName}}{{if and (eq .Name $default.Name) (eq .Receiver $default.Receiver)}}*{{end}}\t" + {{printf "%q" .Synopsis}})
 		{{- end}}
 		err := w.Flush()
-		{{- if .Default}}
+		{{- if .DefaultFunc.Name}}
 		if err == nil {
 			fmt.Println("\n* default target")
 		}
@@ -107,7 +107,7 @@ func main() {
 		log.SetOutput(ioutil.Discard)
 	}
 	logger := log.New(os.Stderr, "", 0)
-	if os.Getenv("MAGEFILE_LIST") != "" {
+	if ok, _ := strconv.ParseBool(os.Getenv("MAGEFILE_LIST")); ok {
 		if err := list(); err != nil {
 			log.Println(err)
 			os.Exit(1)
@@ -137,7 +137,7 @@ func main() {
 		os.Exit(2)
 	}
 
-	if os.Getenv("MAGEFILE_HELP") != "" {
+	if help, _ := strconv.ParseBool(os.Getenv("MAGEFILE_HELP")); help {
 		if len(os.Args) < 2 {
 			logger.Println("no target specified")
 			os.Exit(1)
@@ -151,8 +151,9 @@ func main() {
 				{{end}}
 				var aliases []string
 				{{- $name := .Name -}}
+				{{- $recv := .Receiver -}}
 				{{range $alias, $func := $.Aliases}}
-				{{if eq $name $func}}aliases = append(aliases, "{{$alias}}"){{end -}}
+				{{if and (eq $name $func.Name) (eq $recv $func.Receiver)}}aliases = append(aliases, "{{$alias}}"){{end -}}
 				{{- end}}
 				if len(aliases) > 0 {
 					fmt.Printf("Aliases: %s\n\n", strings.Join(aliases, ", "))
@@ -165,7 +166,7 @@ func main() {
 		}	
 	}
 	if len(os.Args) < 2 {
-	{{- if .Default}}
+	{{- if .DefaultFunc.Name}}
 		ignore, _ := strconv.ParseBool(os.Getenv("MAGEFILE_IGNOREDEFAULT"))
 		if ignore {
 			if err := list(); err != nil {
@@ -189,7 +190,7 @@ func main() {
 		switch strings.ToLower(target) {
 		{{range $alias, $func := .Aliases}}
 		case "{{lower $alias}}":
-			target = "{{$func}}"
+			target = "{{with $func.Receiver}}{{.}}:{{end}}{{$func.Name}}"
 		{{- end}}
 		}
 		switch strings.ToLower(target) {

mage/testdata/namespaces/magefile.go

@@ -9,6 +9,8 @@ import (
 	"github.com/magefile/mage/mg"
 )
 
+var Default = NS.Error
+
 func TestNamespaceDep() {
 	mg.Deps(NS.Error, NS.Bare, NS.BareCtx, NS.CtxErr)
 }

magefile.go

@@ -19,6 +19,10 @@ import (
 	"github.com/magefile/mage/sh"
 )
 
+var Aliases = map[string]interface{}{
+	"foo": Foo.Build,
+}
+
 // Runs "go install" for mage.  This generates the version info the binary.
 func Install() error {
 	name := "mage"
@@ -98,3 +102,9 @@ func hash() string {
 	hash, _ := sh.Output("git", "rev-parse", "--short", "HEAD")
 	return hash
 }
+
+type Foo mg.Namespace
+
+func (Foo) Build() {
+
+}

parse/parse.go

@@ -24,13 +24,10 @@ func EnableDebug() {
 // PkgInfo contains inforamtion about a package of files according to mage's
 // parsing rules.
 type PkgInfo struct {
-	Description      string
-	Funcs            []Function
-	DefaultIsError   bool
-	DefaultIsContext bool
-	DefaultName      string
-	DefaultFunc      Function
-	Aliases          map[string]string
+	Description string
+	Funcs       []Function
+	DefaultFunc Function
+	Aliases     map[string]Function
 }
 
 // Function represented a job function from a mage file
@@ -253,15 +250,20 @@ func setDefault(p *doc.Package, pi *PkgInfo) {
 			if len(spec.Values) != 1 {
 				log.Println("warning: default declaration has multiple values")
 			}
-			id, ok := spec.Values[0].(*ast.Ident)
-			if !ok {
-				log.Println("warning: default declaration is not a function name")
+
+			var name string
+			var receiver string
+			switch v := spec.Values[0].(type) {
+			case *ast.Ident:
+				name = v.Name
+			case *ast.SelectorExpr:
+				name = v.Sel.Name
+				receiver = fmt.Sprintf("%s", v.X)
+			default:
+				log.Printf("warning: target for Default %s is not a function", spec.Values[0])
 			}
 			for _, f := range pi.Funcs {
-				if f.Name == id.Name {
-					pi.DefaultName = f.Name
-					pi.DefaultIsError = f.IsError
-					pi.DefaultIsContext = f.IsContext
+				if f.Name == name && f.Receiver == receiver {
 					pi.DefaultFunc = f
 					return
 				}
@@ -290,7 +292,7 @@ func setAliases(p *doc.Package, pi *PkgInfo) {
 				log.Println("warning: aliases declaration is not a map")
 				return
 			}
-			pi.Aliases = make(map[string]string)
+			pi.Aliases = map[string]Function{}
 			for _, elem := range comp.Elts {
 				kv, ok := elem.(*ast.KeyValueExpr)
 				if !ok {
@@ -302,20 +304,30 @@ func setAliases(p *doc.Package, pi *PkgInfo) {
 					log.Println("warning: alias is not a string")
 					return
 				}
-				v, ok := kv.Value.(*ast.Ident)
-				if !ok {
-					log.Println("warning: alias target is not a function")
-					return
+
+				var name string
+				var receiver string
+				switch v := kv.Value.(type) {
+				case *ast.Ident:
+					name = v.Name
+				case *ast.SelectorExpr:
+					name = v.Sel.Name
+					receiver = fmt.Sprintf("%s", v.X)
+				default:
+					log.Printf("warning: target for alias %s is not a function", k.Value)
 				}
 				alias := strings.Trim(k.Value, "\"")
 				valid := false
 				for _, f := range pi.Funcs {
-					valid = valid || f.Name == v.Name
+					if f.Name == name && f.Receiver == receiver {
+						pi.Aliases[alias] = f
+						valid = true
+						break
+					}
 				}
 				if !valid {
 					log.Printf("warning: alias declaration (%s) does not reference a mage target", alias)
 				}
-				pi.Aliases[alias] = v.Name
 			}
 			return
 		}

parse/parse_test.go

@@ -50,19 +50,31 @@ func TestParse(t *testing.T) {
 	}
 
 	// DefaultIsError
-	if info.DefaultIsError != true {
+	if info.DefaultFunc.IsError != true {
 		t.Fatalf("expected DefaultIsError to be true")
 	}
 
 	// DefaultName
-	if info.DefaultName != "ReturnsNilError" {
+	if info.DefaultFunc.Name != "ReturnsNilError" {
 		t.Fatalf("expected DefaultName to be ReturnsNilError")
 	}
 
-	if info.Aliases["void"] != "ReturnsVoid" {
+	if info.Aliases["void"].Name != "ReturnsVoid" {
 		t.Fatalf("expected alias of void to be ReturnsVoid")
 	}
 
+	f, ok := info.Aliases["baz"]
+	if !ok {
+		t.Fatal("missing alias baz")
+	}
+	if f.Name != "Baz" || f.Receiver != "Build" {
+		t.Fatalf("expected alias of void to be Build.Baz")
+	}
+
+	if len(info.Aliases) != 2 {
+		t.Fatalf("expected to only have two aliases, but have %#v", info.Aliases)
+	}
+
 	for _, fn := range expected {
 		found := false
 		for _, infoFn := range info.Funcs {

parse/testdata/alias.go

@@ -4,4 +4,5 @@ package main
 
 var Aliases = map[string]interface{}{
 	"void": ReturnsVoid,
+	"baz":  Build.Baz,
 }