feat(proxy): implement look-ahead (#43)

go.mod

@@ -5,6 +5,7 @@ go 1.21
 require (
 	github.com/onsi/ginkgo/v2 v2.13.0
 	github.com/onsi/gomega v1.28.1
+	github.com/pkg/errors v0.9.1
 	github.com/samber/lo v1.38.1
 	github.com/snivilised/extendio v0.3.0
 	github.com/snivilised/lorax v0.4.1
@@ -22,7 +23,6 @@ require (
 	github.com/google/uuid v1.3.1 // indirect
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
 	github.com/onsi/ginkgo v1.16.5 // indirect
-	github.com/pkg/errors v0.9.1 // indirect
 	github.com/sagikazarmark/locafero v0.3.0 // indirect
 	github.com/sagikazarmark/slog-shim v0.1.0 // indirect
 	github.com/sourcegraph/conc v0.3.0 // indirect

src/app/command/bootstrap.go

@@ -58,25 +58,25 @@ type ConfigInfo struct {
 // without resorting to the use of Go's init() mechanism and minimal
 // use of package global variables.
 type Bootstrap struct {
-	Container *assistant.CobraContainer
-	options   ConfigureOptions
+	Container   *assistant.CobraContainer
+	optionsInfo ConfigureOptionsInfo
 }
 
-type ConfigureOptions struct {
+type ConfigureOptionsInfo struct {
 	Detector LocaleDetector
 	Executor proxy.Executor
 	Config   ConfigInfo
 }
 
-type ConfigureOptionFn func(*ConfigureOptions)
+type ConfigureOptionFn func(*ConfigureOptionsInfo)
 
 // Root builds the command tree and returns the root command, ready
 // to be executed.
 func (b *Bootstrap) Root(options ...ConfigureOptionFn) *cobra.Command {
 	home, err := os.UserHomeDir()
 	cobra.CheckErr(err)
 
-	b.options = ConfigureOptions{
+	b.optionsInfo = ConfigureOptionsInfo{
 		Detector: &Jabber{},
 		Executor: &ProgramExecutor{
 			Name: "magick",
@@ -89,21 +89,21 @@ func (b *Bootstrap) Root(options ...ConfigureOptionFn) *cobra.Command {
 		},
 	}
 
-	if _, err := b.options.Executor.Look(); err != nil {
-		b.options.Executor = &DummyExecutor{
-			Name: b.options.Executor.ProgName(),
+	if _, err := b.optionsInfo.Executor.Look(); err != nil {
+		b.optionsInfo.Executor = &DummyExecutor{
+			Name: b.optionsInfo.Executor.ProgName(),
 		}
 	}
 
 	for _, fo := range options {
-		fo(&b.options)
+		fo(&b.optionsInfo)
 	}
 
 	b.configure()
 
 	// JUST TEMPORARY: make the executor the dummy for safety
 	//
-	b.options.Executor = &DummyExecutor{
+	b.optionsInfo.Executor = &DummyExecutor{
 		Name: "magick",
 	}
 
@@ -126,7 +126,7 @@ func (b *Bootstrap) Root(options ...ConfigureOptionFn) *cobra.Command {
 
 				// ---> execute root core
 				//
-				return proxy.EnterRoot(inputs, b.options.Executor, b.options.Config.Viper)
+				return proxy.EnterRoot(inputs, b.optionsInfo.Executor, b.optionsInfo.Config.Viper)
 			},
 		},
 	)
@@ -139,8 +139,8 @@ func (b *Bootstrap) Root(options ...ConfigureOptionFn) *cobra.Command {
 }
 
 func (b *Bootstrap) configure() {
-	vc := b.options.Config.Viper
-	ci := b.options.Config
+	vc := b.optionsInfo.Config.Viper
+	ci := b.optionsInfo.Config
 
 	vc.SetConfigName(ci.Name)
 	vc.SetConfigType(ci.ConfigType)

src/app/command/bootstrap_test.go

@@ -49,7 +49,7 @@ var _ = Describe("Bootstrap", Ordered, func() {
 	Context("given: root defined with magick sub-command", func() {
 		It("🧪 should: setup command without error", func() {
 			bootstrap := command.Bootstrap{}
-			rootCmd := bootstrap.Root(func(co *command.ConfigureOptions) {
+			rootCmd := bootstrap.Root(func(co *command.ConfigureOptionsInfo) {
 				co.Detector = &DetectorStub{}
 				co.Executor = &ExecutorStub{
 					Name: "magick",

src/app/command/magick-cmd_test.go

@@ -55,7 +55,7 @@ var _ = Describe("MagickCmd", Ordered, func() {
 			bootstrap := command.Bootstrap{}
 			tester := helpers.CommandTester{
 				Args: []string{"mag"},
-				Root: bootstrap.Root(func(co *command.ConfigureOptions) {
+				Root: bootstrap.Root(func(co *command.ConfigureOptionsInfo) {
 					co.Detector = &DetectorStub{}
 				}),
 			}

src/app/command/root-cmd_test.go

@@ -35,7 +35,7 @@ var _ = Describe("RootCmd", Ordered, func() {
 		bootstrap := command.Bootstrap{}
 		tester = helpers.CommandTester{
 			Args: []string{"./"},
-			Root: bootstrap.Root(func(co *command.ConfigureOptions) {
+			Root: bootstrap.Root(func(co *command.ConfigureOptionsInfo) {
 				co.Detector = &DetectorStub{}
 				co.Executor = &ExecutorStub{
 					Name: "magick",
@@ -49,7 +49,7 @@ var _ = Describe("RootCmd", Ordered, func() {
 			bootstrap := command.Bootstrap{}
 			tester = helpers.CommandTester{
 				Args: entry.commandLine,
-				Root: bootstrap.Root(func(co *command.ConfigureOptions) {
+				Root: bootstrap.Root(func(co *command.ConfigureOptionsInfo) {
 					co.Detector = &DetectorStub{}
 					co.Executor = &ExecutorStub{
 						Name: "magick",

src/app/command/shrink-cmd.go

@@ -124,8 +124,8 @@ func (b *Bootstrap) buildShrinkCommand(container *assistant.CobraContainer) *cob
 
 					appErr = proxy.EnterShrink(
 						inputs,
-						b.options.Executor,
-						b.options.Config.Viper,
+						b.optionsInfo.Executor,
+						b.optionsInfo.Config.Viper,
 					)
 				} else {
 					return xvErr

src/app/command/shrink-cmd_test.go

@@ -40,7 +40,7 @@ func expectValidShrinkCmdInvocation(entry *shrinkTE) {
 
 	tester := helpers.CommandTester{
 		Args: append(options, entry.args...),
-		Root: bootstrap.Root(func(co *command.ConfigureOptions) {
+		Root: bootstrap.Root(func(co *command.ConfigureOptionsInfo) {
 			co.Detector = &DetectorStub{}
 			co.Executor = &ExecutorStub{
 				Name: "magick",

src/app/proxy/config_test.go

@@ -33,7 +33,7 @@ func expectValidShrinkCmdInvocation(entry *configTE) {
 
 	tester := helpers.CommandTester{
 		Args: append(options, entry.args...),
-		Root: bootstrap.Root(func(co *command.ConfigureOptions) {
+		Root: bootstrap.Root(func(co *command.ConfigureOptionsInfo) {
 			co.Detector = &helpers.DetectorStub{}
 			co.Executor = &helpers.ExecutorStub{
 				Name: prog,

src/app/proxy/enter-root.go

@@ -35,6 +35,25 @@ type RootEntry struct {
 	files []string
 }
 
+func (e *RootEntry) principalFn(item *nav.TraverseItem) error {
+	depth := item.Extension.Depth
+	indicator := lo.Ternary(len(item.Children) > 0, "☀️", "🌊")
+
+	for _, entry := range item.Children {
+		fullPath := filepath.Join(item.Path, entry.Name())
+		e.files = append(e.files, fullPath)
+	}
+
+	fmt.Printf(
+		"---> %v ROOT-CALLBACK: (depth:%v, files:%v) '%v'\n",
+		indicator,
+		depth, len(item.Children),
+		item.Path,
+	)
+
+	return e.Program.Execute("--version")
+}
+
 func (e *RootEntry) ConfigureOptions(o *nav.TraverseOptions) {
 	o.Notify.OnBegin = func(_ *nav.NavigationState) {
 		fmt.Printf("===> 🛡️ beginning traversal ...\n")
@@ -46,68 +65,39 @@ func (e *RootEntry) ConfigureOptions(o *nav.TraverseOptions) {
 	}
 	o.Callback = &nav.LabelledTraverseCallback{
 		Label: "Root Entry Callback",
-		Fn: func(item *nav.TraverseItem) error {
-			depth := item.Extension.Depth
-			indicator := lo.Ternary(len(item.Children) > 0, "☀️", "🌊")
-
-			for _, entry := range item.Children {
-				fullPath := filepath.Join(item.Path, entry.Name())
-				e.files = append(e.files, fullPath)
-			}
-
-			fmt.Printf(
-				"---> %v ROOT-CALLBACK: (depth:%v, files:%v) '%v'\n",
-				indicator,
-				depth, len(item.Children),
-				item.Path,
-			)
-
-			return e.Program.Execute("--version")
-		},
+		Fn:    e.principalFn,
 	}
 	o.Store.Subscription = nav.SubscribeFoldersWithFiles
 	o.Store.DoExtend = true
 	e.EntryBase.ConfigureOptions(o)
 }
 
 func (e *RootEntry) run() error {
-	files := []string{}
 	runnerWith := composeWith(e.Inputs.ParamSet)
-	resumption := &nav.Resumption{
-		RestorePath: "/json-path-to-come-from-a-flag-option/restore.json",
-		Restorer: func(o *nav.TraverseOptions, active *nav.ActiveState) {
-			o.Callback = &nav.LabelledTraverseCallback{
-				Label: "Root Entry Callback",
-				Fn: func(item *nav.TraverseItem) error {
-					depth := item.Extension.Depth
-					indicator := lo.Ternary(len(item.Children) > 0, "☀️", "🌊")
-
-					for _, entry := range item.Children {
-						fullPath := filepath.Join(item.Path, entry.Name())
-						files = append(files, fullPath)
-					}
-
-					fmt.Printf(
-						"---> %v ROOT-CALLBACK: (depth:%v, files:%v) '%v'\n",
-						indicator,
-						depth, len(item.Children),
-						item.Path,
-					)
-
-					return nil
-				},
-			}
-		},
-		Strategy: nav.ResumeStrategySpawnEn, // to come from an arg
-	}
+
+	var nilResumption *nav.Resumption // root does not need to support resume
 
 	after := func(result *nav.TraverseResult, err error) {
 		for _, file := range e.files {
 			fmt.Printf("		===> 🔆 candidate file: '%v'\n", file)
 		}
 	}
 
-	return e.navigate(GetTraverseOptionsFunc(e), runnerWith, resumption, after)
+	principal := func(o *nav.TraverseOptions) {
+		e.ConfigureOptions(o)
+		o.Callback = &nav.LabelledTraverseCallback{
+			Label: "Root Entry Callback",
+			Fn:    e.principalFn,
+		}
+	}
+
+	return e.navigate(
+		principal,
+		runnerWith,
+		nilResumption,
+		after,
+		summariseAfter,
+	)
 }
 
 func composeWith(rps *assistant.ParamSet[RootParameterSet]) nav.CreateNewRunnerWith {