Added package empty

This package adds the code generation for package empty, which provides
structs that has no-op asserter methods for ease of use.

The package demonstrates one of the many possible use cases of having a
repository ready for code generation.

cmd/internal/cchat-empty-gen/main.go

@@ -0,0 +1,85 @@
+package main
+
+import (
+	"fmt"
+	"log"
+	"os"
+
+	"github.com/dave/jennifer/jen"
+	"github.com/diamondburned/cchat/cmd/internal/cchat-generator/genutils"
+	"github.com/diamondburned/cchat/repository"
+)
+
+const OutputDir = "."
+
+func init() {
+	log.SetFlags(0)
+}
+
+var comment = repository.Comment{Raw: `
+	Package empty provides no-op asserter method implementations of interfaces
+	in cchat.
+`}
+
+func main() {
+	pk, ok := repository.Main[repository.RootPath]
+	if !ok {
+		log.Fatalf("Failed to find main namespace %q\n", repository.RootPath)
+	}
+
+	gen := jen.NewFile("empty")
+	gen.HeaderComment("DO NOT EDIT: THIS FILE IS GENERATED!")
+	gen.PackageComment(comment.GoString(1))
+
+	for _, iface := range pk.Interfaces {
+		// Skip structs without asserter methods.
+		if !hasAsserter(iface) {
+			continue
+		}
+
+		gen.Commentf("%[1]s provides no-op asserters for cchat.%[1]s.", iface.Name)
+		gen.Type().Id(iface.Name).Struct()
+		gen.Line()
+
+		for _, method := range iface.Methods {
+			am, ok := method.(repository.AsserterMethod)
+			if !ok {
+				continue
+			}
+
+			name := fmt.Sprintf("As%s", am.ChildType)
+			gen.Comment(fmt.Sprintf("%s returns nil.", name))
+
+			stmt := jen.Func()
+			stmt.Parens(jen.Id(iface.Name))
+			stmt.Id(fmt.Sprintf("As%s", am.ChildType))
+			stmt.Params()
+			stmt.Add(genutils.GenerateExternType(am))
+			stmt.Values(jen.Return(jen.Nil()))
+
+			gen.Add(stmt)
+		}
+
+		gen.Line()
+	}
+
+	f, err := os.Create("empty.go")
+	if err != nil {
+		log.Fatalln("Failed to create output file:", err)
+	}
+	defer f.Close()
+
+	if err := gen.Render(f); err != nil {
+		log.Fatalln("Failed to render output:", err)
+	}
+}
+
+func hasAsserter(iface repository.Interface) bool {
+	for _, method := range iface.Methods {
+		if _, isA := method.(repository.AsserterMethod); isA {
+			return true
+		}
+	}
+
+	return false
+}

cmd/internal/cchat-generator/generate_enum.go

@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"github.com/dave/jennifer/jen"
+	"github.com/diamondburned/cchat/cmd/internal/cchat-generator/genutils"
 	"github.com/diamondburned/cchat/repository"
 )
 
@@ -45,7 +46,7 @@ func generateEnums(enums []repository.Enumeration) jen.Code {
 		stmt.Line()
 		stmt.Line()
 
-		var recv = recvName(enum.Name)
+		var recv = genutils.RecvName(enum.Name)
 
 		if enum.Bitwise {
 			fn := stmt.Func()

cmd/internal/cchat-generator/generate_interface.go

@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"github.com/dave/jennifer/jen"
+	"github.com/diamondburned/cchat/cmd/internal/cchat-generator/genutils"
 	"github.com/diamondburned/cchat/repository"
 )
 
@@ -71,7 +72,7 @@ func generateInterfaces(ifaces []repository.Interface) jen.Code {
 					stmt.Params(generateContainerFuncReturns(method)...)
 				case repository.AsserterMethod:
 					stmt.Params()
-					stmt.Params(generateType(method))
+					stmt.Params(genutils.GenerateType(method))
 					stmt.Comment("// Optional")
 				default:
 					continue
@@ -108,9 +109,9 @@ func generateFuncParamErr(param repository.NamedType, genErr bool) []jen.Code {
 
 func generateFuncParam(param repository.NamedType) jen.Code {
 	if param.Name == "" {
-		return generateType(param)
+		return genutils.GenerateType(param)
 	}
-	return jen.Id(param.Name).Add(generateType(param))
+	return jen.Id(param.Name).Add(genutils.GenerateType(param))
 }
 
 func generateFuncParams(params []repository.NamedType, withError bool) []jen.Code {
@@ -151,7 +152,7 @@ func generateContainerFuncParams(method repository.ContainerMethod) []jen.Code {
 	if method.HasContext {
 		stmt.Qual("context", "Context")
 	}
-	stmt.Add(generateType(method))
+	stmt.Add(genutils.GenerateType(method))
 
 	return stmt
 }

cmd/internal/cchat-generator/generate_struct.go

@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"github.com/dave/jennifer/jen"
+	"github.com/diamondburned/cchat/cmd/internal/cchat-generator/genutils"
 	"github.com/diamondburned/cchat/repository"
 )
 
@@ -35,7 +36,7 @@ func generateErrorStructs(errStructs []repository.ErrorStruct) jen.Code {
 		stmt.Line()
 		stmt.Line()
 
-		var recv = recvName(errStruct.Name)
+		var recv = genutils.RecvName(errStruct.Name)
 
 		stmt.Func()
 		stmt.Params(jen.Id(recv).Id(errStruct.Name))
@@ -81,7 +82,7 @@ func generateStruct(s repository.Struct) jen.Code {
 			if field.Name != "" {
 				stmt.Id(field.Name)
 			}
-			stmt.Add(generateType(field))
+			stmt.Add(genutils.GenerateType(field))
 			group.Add(stmt)
 		}
 	})

cmd/internal/cchat-generator/generate_type.go

@@ -4,6 +4,7 @@ import (
 	"sort"
 
 	"github.com/dave/jennifer/jen"
+	"github.com/diamondburned/cchat/cmd/internal/cchat-generator/genutils"
 	"github.com/diamondburned/cchat/repository"
 )
 
@@ -20,22 +21,10 @@ func generateTypeAlises(aliases []repository.TypeAlias) jen.Code {
 			stmt.Line()
 		}
 
-		stmt.Type().Id(alias.Name).Op("=").Add(generateType(alias))
+		stmt.Type().Id(alias.Name).Op("=").Add(genutils.GenerateType(alias))
 		stmt.Line()
 		stmt.Line()
 	}
 
 	return stmt
 }
-
-type qualer interface {
-	Qual() (path, name string)
-}
-
-func generateType(t qualer) jen.Code {
-	path, name := t.Qual()
-	if path == "" {
-		return jen.Id(name)
-	}
-	return jen.Qual(path, name)
-}

cmd/internal/cchat-generator/genutils/genutils.go

@@ -0,0 +1,37 @@
+package genutils
+
+import (
+	"unicode"
+
+	"github.com/dave/jennifer/jen"
+	"github.com/diamondburned/cchat/repository"
+)
+
+type Qualer interface {
+	Qual() (path, name string)
+}
+
+// GenerateType generates a jen.Qual from the given Qualer.
+func GenerateType(t Qualer) jen.Code {
+	path, name := t.Qual()
+	if path == "" {
+		return jen.Id(name)
+	}
+	return jen.Qual(path, name)
+}
+
+// GenerateExternType generates a jen.Qual from the given Qualer, except if
+// the path is empty, RootPath is used instead.
+func GenerateExternType(t Qualer) jen.Code {
+	path, name := t.Qual()
+	if path == "" {
+		return jen.Qual(repository.RootPath, name)
+	}
+	return jen.Qual(path, name)
+}
+
+// RecvName is used to get the receiver variable name. It returns the first
+// letter lower-cased. It does NOT do length checking. It only works with ASCII.
+func RecvName(name string) string {
+	return string(unicode.ToLower(rune(name[0])))
+}

cmd/internal/cchat-generator/main.go

@@ -5,7 +5,6 @@ import (
 	"os"
 	"path/filepath"
 	"strings"
-	"unicode"
 
 	"github.com/dave/jennifer/jen"
 	"github.com/diamondburned/cchat/repository"
@@ -48,12 +47,6 @@ func trimPrefix(rootPrefix, path string) string {
 	return strings.Trim(strings.TrimPrefix(path, rootPrefix), "/")
 }
 
-// recvName is used to get the receiver variable name. It returns the first
-// letter lower-cased. It does NOT do length checking. It only works with ASCII.
-func recvName(name string) string {
-	return string(unicode.ToLower(rune(name[0])))
-}
-
 func generate(pkgPath string, repo repository.Package) *jen.File {
 	gen := jen.NewFilePath(pkgPath)
 	gen.HeaderComment("DO NOT EDIT: THIS FILE IS GENERATED!")

generator.go

@@ -1,3 +1,3 @@
 package cchat
 
-//go:generate go run ./cmd/cchat-generator
+//go:generate go run ./cmd/internal/cchat-generator

repository/gob/generator.go

@@ -1,3 +1,5 @@
+// +build ignore
+
 package main
 
 //go:generate go run ./generator.go

repository/main.go

@@ -5,7 +5,7 @@ package repository
 const RootPath = "github.com/diamondburned/cchat"
 
 var Main = Packages{
-	"github.com/diamondburned/cchat/text": {
+	MakePath("text"): {
 		Comment: Comment{`
 			Package text provides a rich text API for cchat interfaces to use.
 		`},
@@ -210,7 +210,7 @@ var Main = Packages{
 						Name: "MentionInfo",
 					},
 					Returns: []NamedType{{
-						Type: "(github.com/diamondburned/cchat/text).Rich",
+						Type: MakeQual("text", "Rich"),
 					}},
 				},
 			},
@@ -462,7 +462,7 @@ var Main = Packages{
 				`},
 				NamedType: NamedType{
 					Name: "Text",
-					Type: "(github.com/diamondburned/cchat/text).Rich",
+					Type: MakeQual("text", "Rich"),
 				},
 			}, {
 				Comment: Comment{`
@@ -472,7 +472,7 @@ var Main = Packages{
 				`},
 				NamedType: NamedType{
 					Name: "Secondary",
-					Type: "(github.com/diamondburned/cchat/text).Rich",
+					Type: MakeQual("text", "Rich"),
 				},
 			}, {
 				Comment: Comment{`
@@ -545,7 +545,7 @@ var Main = Packages{
 				GetterMethod{
 					method: method{Name: "Name"},
 					Returns: []NamedType{{
-						Type: "(github.com/diamondburned/cchat/text).Rich",
+						Type: MakeQual("text", "Rich"),
 					}},
 				},
 				AsserterMethod{
@@ -1366,7 +1366,7 @@ var Main = Packages{
 				GetterMethod{
 					method: method{Name: "Content"},
 					Returns: []NamedType{{
-						Type: "(github.com/diamondburned/cchat/text).Rich",
+						Type: MakeQual("text", "Rich"),
 					}},
 				},
 				GetterMethod{
@@ -1396,7 +1396,7 @@ var Main = Packages{
 				GetterMethod{
 					method: method{Name: "Content"},
 					Returns: []NamedType{{
-						Type: "(github.com/diamondburned/cchat/text).Rich",
+						Type: MakeQual("text", "Rich"),
 					}},
 				},
 			},
@@ -1422,7 +1422,7 @@ var Main = Packages{
 				SetterMethod{
 					method: method{Name: "SetLabel"},
 					Parameters: []NamedType{{
-						Type: "(github.com/diamondburned/cchat/text).Rich",
+						Type: MakeQual("text", "Rich"),
 					}},
 				},
 			},
@@ -1650,7 +1650,7 @@ var Main = Packages{
 						Name: "Secondary",
 					},
 					Returns: []NamedType{{
-						Type: "(github.com/diamondburned/cchat/text).Rich",
+						Type: MakeQual("text", "Rich"),
 					}},
 				},
 			},

repository/repository.go

@@ -1,9 +1,22 @@
 package repository
 
 import (
+	"fmt"
+	"path"
 	"strings"
 )
 
+// MakePath returns RootPath joined with relPath.
+func MakePath(relPath string) string {
+	return path.Join(RootPath, relPath)
+}
+
+// MakeQual returns a qualified identifier that is the full path and name of
+// something.
+func MakeQual(relPath, name string) string {
+	return fmt.Sprintf("(%s).%s", MakePath(relPath), name)
+}
+
 // Packages maps Go module paths to packages.
 type Packages map[string]Package
 

utils/empty/empty.go

@@ -0,0 +1,100 @@
+// DO NOT EDIT: THIS FILE IS GENERATED!
+
+// Package empty provides no-op asserter method implementations of interfaces in
+// cchat.
+package empty
+
+import cchat "github.com/diamondburned/cchat"
+
+// Namer provides no-op asserters for cchat.Namer.
+type Namer struct{}
+
+// AsIconer returns nil.
+func (Namer) AsIconer() cchat.Iconer { return nil }
+
+// Service provides no-op asserters for cchat.Service.
+type Service struct{}
+
+// AsConfigurator returns nil.
+func (Service) AsConfigurator() cchat.Configurator { return nil }
+
+// AsSessionRestorer returns nil.
+func (Service) AsSessionRestorer() cchat.SessionRestorer { return nil }
+
+// Session provides no-op asserters for cchat.Session.
+type Session struct{}
+
+// AsCommander returns nil.
+func (Session) AsCommander() cchat.Commander { return nil }
+
+// AsSessionSaver returns nil.
+func (Session) AsSessionSaver() cchat.SessionSaver { return nil }
+
+// Commander provides no-op asserters for cchat.Commander.
+type Commander struct{}
+
+// AsCompleter returns nil.
+func (Commander) AsCompleter() cchat.Completer { return nil }
+
+// Server provides no-op asserters for cchat.Server.
+type Server struct{}
+
+// AsLister returns nil.
+func (Server) AsLister() cchat.Lister { return nil }
+
+// AsMessenger returns nil.
+func (Server) AsMessenger() cchat.Messenger { return nil }
+
+// AsCommander returns nil.
+func (Server) AsCommander() cchat.Commander { return nil }
+
+// AsConfigurator returns nil.
+func (Server) AsConfigurator() cchat.Configurator { return nil }
+
+// Messenger provides no-op asserters for cchat.Messenger.
+type Messenger struct{}
+
+// AsSender returns nil.
+func (Messenger) AsSender() cchat.Sender { return nil }
+
+// AsEditor returns nil.
+func (Messenger) AsEditor() cchat.Editor { return nil }
+
+// AsActioner returns nil.
+func (Messenger) AsActioner() cchat.Actioner { return nil }
+
+// AsNicknamer returns nil.
+func (Messenger) AsNicknamer() cchat.Nicknamer { return nil }
+
+// AsBacklogger returns nil.
+func (Messenger) AsBacklogger() cchat.Backlogger { return nil }
+
+// AsMemberLister returns nil.
+func (Messenger) AsMemberLister() cchat.MemberLister { return nil }
+
+// AsUnreadIndicator returns nil.
+func (Messenger) AsUnreadIndicator() cchat.UnreadIndicator { return nil }
+
+// AsTypingIndicator returns nil.
+func (Messenger) AsTypingIndicator() cchat.TypingIndicator { return nil }
+
+// Sender provides no-op asserters for cchat.Sender.
+type Sender struct{}
+
+// AsCompleter returns nil.
+func (Sender) AsCompleter() cchat.Completer { return nil }
+
+// MemberSection provides no-op asserters for cchat.MemberSection.
+type MemberSection struct{}
+
+// AsMemberDynamicSection returns nil.
+func (MemberSection) AsMemberDynamicSection() cchat.MemberDynamicSection { return nil }
+
+// SendableMessage provides no-op asserters for cchat.SendableMessage.
+type SendableMessage struct{}
+
+// AsNoncer returns nil.
+func (SendableMessage) AsNoncer() cchat.Noncer { return nil }
+
+// AsAttachments returns nil.
+func (SendableMessage) AsAttachments() cchat.Attachments { return nil }

utils/empty/generator.go

@@ -0,0 +1,3 @@
+package main
+
+//go:generate go run ../../cmd/internal/cchat-empty-gen