Port tsc --init

internal/execute/tsc.go

@@ -113,7 +113,8 @@ func tscCompilation(sys tsc.System, commandLine *tsoptions.ParsedCommandLine, te
 	}
 
 	if commandLine.CompilerOptions().Init.IsTrue() {
-		return tsc.CommandLineResult{Status: tsc.ExitStatusNotImplemented}
+		tsc.WriteConfigFile(sys, reportDiagnostic, commandLine.CompilerOptions())
+		return tsc.CommandLineResult{Status: tsc.ExitStatusSuccess}
 	}
 
 	if commandLine.CompilerOptions().Version.IsTrue() {

internal/execute/tsc/init.go

@@ -0,0 +1,238 @@
+package tsc
+
+import (
+	"fmt"
+	"reflect"
+	"slices"
+	"strings"
+
+	"github.com/microsoft/typescript-go/internal/ast"
+	"github.com/microsoft/typescript-go/internal/collections"
+	"github.com/microsoft/typescript-go/internal/core"
+	"github.com/microsoft/typescript-go/internal/diagnostics"
+	"github.com/microsoft/typescript-go/internal/jsonutil"
+	"github.com/microsoft/typescript-go/internal/tsoptions"
+	"github.com/microsoft/typescript-go/internal/tspath"
+)
+
+func WriteConfigFile(sys System, reportDiagnostic DiagnosticReporter, options *core.CompilerOptions) {
+	getCurrentDirectory := sys.GetCurrentDirectory()
+	file := tspath.NormalizePath(tspath.CombinePaths(getCurrentDirectory, "tsconfig.json"))
+	if sys.FS().FileExists(file) {
+		reportDiagnostic(ast.NewCompilerDiagnostic(diagnostics.A_tsconfig_json_file_is_already_defined_at_Colon_0, file))
+	} else {
+		_ = sys.FS().WriteFile(file, generateTSConfig(options), false)
+		output := []string{"\n"}
+		output = append(output, getHeader(sys, "Created a new tsconfig.json")...)
+		output = append(output, "You can learn more at https://aka.ms/tsconfig", "\n")
+		fmt.Fprint(sys.Writer(), strings.Join(output, ""))
+	}
+}
+
+func convertOptionsToMap(options *core.CompilerOptions) *collections.OrderedMap[string, any] {
+	val := reflect.ValueOf(options).Elem()
+	typ := val.Type()
+
+	result := collections.NewOrderedMapWithSizeHint[string, any](val.NumField())
+
+	for i := range val.NumField() {
+		field := typ.Field(i)
+		fieldValue := val.Field(i)
+
+		if fieldValue.IsZero() {
+			continue
+		}
+
+		// Get the field name, considering 'json' tag if present
+		fieldName := field.Name
+		if jsonTag := field.Tag.Get("json"); jsonTag != "" {
+			fieldName, _, _ = strings.Cut(jsonTag, ",")
+		}
+
+		if fieldName != "" && fieldName != "init" && fieldName != "help" && fieldName != "watch" {
+			result.Set(fieldName, fieldValue.Interface())
+		}
+	}
+	return result
+}
+
+func generateTSConfig(options *core.CompilerOptions) string {
+	const tab = "  "
+	var result []string
+
+	optionsMap := convertOptionsToMap(options)
+	allSetOptions := slices.Collect(optionsMap.Keys())
+
+	// !!! locale getLocaleSpecificMessage
+	emitHeader := func(header *diagnostics.Message) {
+		result = append(result, tab+tab+"// "+header.Format())
+	}
+	newline := func() {
+		result = append(result, "")
+	}
+	push := func(args ...string) {
+		result = append(result, args...)
+	}
+
+	formatSingleValue := func(value any, enumMap *collections.OrderedMap[string, any]) string {
+		if enumMap != nil {
+			var found bool
+			for k, v := range enumMap.Entries() {
+				if value == v {
+					value = k
+					found = true
+					break
+				}
+			}
+			if !found {
+				panic(fmt.Sprintf("No matching value of %v", value))
+			}
+		}
+
+		b, err := jsonutil.MarshalIndent(value, "", "")
+		if err != nil {
+			panic(fmt.Sprintf("should not happen: %v", err))
+		}
+		return string(b)
+	}
+
+	formatValueOrArray := func(settingName string, value any) string {
+		var option *tsoptions.CommandLineOption
+		for _, decl := range tsoptions.OptionsDeclarations {
+			if decl.Name == settingName {
+				option = decl
+			}
+		}
+		if option == nil {
+			panic(`No option named ` + settingName)
+		}
+
+		rval := reflect.ValueOf(value)
+		if rval.Kind() == reflect.Slice {
+			var enumMap *collections.OrderedMap[string, any]
+			if elemOption := option.Elements(); elemOption != nil {
+				enumMap = elemOption.EnumMap()
+			}
+
+			var elems []string
+			for i := range rval.Len() {
+				elems = append(elems, formatSingleValue(rval.Index(i).Interface(), enumMap))
+			}
+			return `[` + strings.Join(elems, ", ") + `]`
+		} else {
+			return formatSingleValue(value, option.EnumMap())
+		}
+	}
+
+	// commentedNever': Never comment this out
+	// commentedAlways': Always comment this out, even if it's on commandline
+	// commentedOptional': Comment out unless it's on commandline
+	const (
+		commentedNever    = 0
+		commentedAlways   = 1
+		commentedOptional = 2
+	)
+	emitOption := func(setting string, defaultValue any, commented int) {
+		if commented > 2 {
+			panic("should not happen: invalid `commented`, must be a bug.")
+		}
+
+		existingOptionIndex := slices.Index(allSetOptions, setting)
+		if existingOptionIndex >= 0 {
+			allSetOptions = slices.Delete(allSetOptions, existingOptionIndex, existingOptionIndex+1)
+		}
+
+		var comment bool
+		switch commented {
+		case commentedAlways:
+			comment = true
+		case commentedNever:
+			comment = false
+		default:
+			comment = !optionsMap.Has(setting)
+		}
+
+		value, ok := optionsMap.Get(setting)
+		if !ok {
+			value = defaultValue
+		}
+
+		if comment {
+			push(tab + tab + `// "` + setting + `": ` + formatValueOrArray(setting, value) + `,`)
+		} else {
+			push(tab + tab + `"` + setting + `": ` + formatValueOrArray(setting, value) + `,`)
+		}
+	}
+
+	push("{")
+	// !!! locale getLocaleSpecificMessage
+	push(tab + `// ` + diagnostics.Visit_https_Colon_Slash_Slashaka_ms_Slashtsconfig_to_read_more_about_this_file.Format())
+	push(tab + `"compilerOptions": {`)
+
+	emitHeader(diagnostics.File_Layout)
+	emitOption("rootDir", "./src", commentedOptional)
+	emitOption("outDir", "./dist", commentedOptional)
+
+	newline()
+
+	emitHeader(diagnostics.Environment_Settings)
+	emitHeader(diagnostics.See_also_https_Colon_Slash_Slashaka_ms_Slashtsconfig_Slashmodule)
+	emitOption("module", core.ModuleKindNodeNext, commentedNever)
+	emitOption("target", core.ScriptTargetESNext, commentedNever)
+	emitOption("types", []any{}, commentedNever)
+	if len(options.Lib) != 0 {
+		emitOption("lib", options.Lib, commentedNever)
+	}
+	emitHeader(diagnostics.For_nodejs_Colon)
+	push(tab + tab + `// "lib": ["esnext"],`)
+	push(tab + tab + `// "types": ["node"],`)
+	emitHeader(diagnostics.X_and_npm_install_D_types_Slashnode)
+
+	newline()
+
+	emitHeader(diagnostics.Other_Outputs)
+	emitOption("sourceMap" /*defaultValue*/, true, commentedNever)
+	emitOption("declaration" /*defaultValue*/, true, commentedNever)
+	emitOption("declarationMap" /*defaultValue*/, true, commentedNever)
+
+	newline()
+
+	emitHeader(diagnostics.Stricter_Typechecking_Options)
+	emitOption("noUncheckedIndexedAccess" /*defaultValue*/, true, commentedNever)
+	emitOption("exactOptionalPropertyTypes" /*defaultValue*/, true, commentedNever)
+
+	newline()
+
+	emitHeader(diagnostics.Style_Options)
+	emitOption("noImplicitReturns" /*defaultValue*/, true, commentedOptional)
+	emitOption("noImplicitOverride" /*defaultValue*/, true, commentedOptional)
+	emitOption("noUnusedLocals" /*defaultValue*/, true, commentedOptional)
+	emitOption("noUnusedParameters" /*defaultValue*/, true, commentedOptional)
+	emitOption("noFallthroughCasesInSwitch" /*defaultValue*/, true, commentedOptional)
+	emitOption("noPropertyAccessFromIndexSignature" /*defaultValue*/, true, commentedOptional)
+
+	newline()
+
+	emitHeader(diagnostics.Recommended_Options)
+	emitOption("strict" /*defaultValue*/, true, commentedNever)
+	emitOption("jsx", core.JsxEmitReactJSX, commentedNever)
+	emitOption("verbatimModuleSyntax" /*defaultValue*/, true, commentedNever)
+	emitOption("isolatedModules" /*defaultValue*/, true, commentedNever)
+	emitOption("noUncheckedSideEffectImports" /*defaultValue*/, true, commentedNever)
+	emitOption("moduleDetection", core.ModuleDetectionKindForce, commentedNever)
+	emitOption("skipLibCheck" /*defaultValue*/, true, commentedNever)
+
+	// Write any user-provided options we haven't already
+	if len(allSetOptions) > 0 {
+		newline()
+		for len(allSetOptions) > 0 {
+			emitOption(allSetOptions[0], optionsMap.GetOrZero(allSetOptions[0]), commentedNever)
+		}
+	}
+
+	push(tab + "}")
+	push(`}`)
+	push(``)
+
+	return strings.Join(result, "\n")
+}

internal/execute/tsctests/tsc_test.go

@@ -36,6 +36,28 @@ func TestTscCommandline(t *testing.T) {
 			subScenario:     "when build not first argument",
 			commandLineArgs: []string{"--verbose", "--build"},
 		},
+		{
+			subScenario:     "init",
+			commandLineArgs: []string{"--init"},
+		},
+		{
+			subScenario:     "init with --lib esnext",
+			commandLineArgs: []string{"--init", "--lib", "esnext"},
+		},
+		{
+			subScenario:     "init with tsconfig.json",
+			commandLineArgs: []string{"--init"},
+			files: FileMap{
+				"/home/src/workspaces/project/first.ts": `export const a = 1`,
+				"/home/src/workspaces/project/tsconfig.json": stringtestutil.Dedent(`
+				{
+					"compilerOptions": {
+						"strict": true,
+						"noEmit": true
+					}
+				}`),
+			},
+		},
 		{
 			subScenario:     "help",
 			commandLineArgs: []string{"--help"},

testdata/baselines/reference/tsc/commandLine/init-with---lib-esnext.js

@@ -0,0 +1,59 @@
+currentDirectory::/home/src/workspaces/project
+useCaseSensitiveFileNames::true
+Input::
+
+tsgo --init --lib esnext
+ExitStatus:: Success
+Output::
+
+Created a new tsconfig.json
+
+You can learn more at https://aka.ms/tsconfig
+//// [/home/src/workspaces/project/tsconfig.json] *new* 
+{
+  // Visit https://aka.ms/tsconfig to read more about this file
+  "compilerOptions": {
+    // File Layout
+    // "rootDir": "./src",
+    // "outDir": "./dist",
+
+    // Environment Settings
+    // See also https://aka.ms/tsconfig/module
+    "module": "nodenext",
+    "target": "esnext",
+    "types": [],
+    "lib": ["esnext"],
+    // For nodejs:
+    // "lib": ["esnext"],
+    // "types": ["node"],
+    // and npm install -D @types/node
+
+    // Other Outputs
+    "sourceMap": true,
+    "declaration": true,
+    "declarationMap": true,
+
+    // Stricter Typechecking Options
+    "noUncheckedIndexedAccess": true,
+    "exactOptionalPropertyTypes": true,
+
+    // Style Options
+    // "noImplicitReturns": true,
+    // "noImplicitOverride": true,
+    // "noUnusedLocals": true,
+    // "noUnusedParameters": true,
+    // "noFallthroughCasesInSwitch": true,
+    // "noPropertyAccessFromIndexSignature": true,
+
+    // Recommended Options
+    "strict": true,
+    "jsx": "react-jsx",
+    "verbatimModuleSyntax": true,
+    "isolatedModules": true,
+    "noUncheckedSideEffectImports": true,
+    "moduleDetection": "force",
+    "skipLibCheck": true,
+  }
+}
+
+

testdata/baselines/reference/tsc/commandLine/init-with-tsconfig.json.js

@@ -0,0 +1,18 @@
+currentDirectory::/home/src/workspaces/project
+useCaseSensitiveFileNames::true
+Input::
+//// [/home/src/workspaces/project/first.ts] *new* 
+export const a = 1
+//// [/home/src/workspaces/project/tsconfig.json] *new* 
+{
+    "compilerOptions": {
+        "strict": true,
+        "noEmit": true
+    }
+}
+
+tsgo --init
+ExitStatus:: Success
+Output::
+error TS5054: A 'tsconfig.json' file is already defined at: '/home/src/workspaces/project/tsconfig.json'.
+