Remove Node12, add Node16.

Author: DanielRosenwasser

src/compiler/checker.ts

@@ -1048,7 +1048,7 @@ namespace ts {
         const builtinGlobals = createSymbolTable();
         builtinGlobals.set(undefinedSymbol.escapedName, undefinedSymbol);
 
-        // Extensions suggested for path imports when module resolution is node12 or higher.
+        // Extensions suggested for path imports when module resolution is node16 or higher.
         // The first element of each tuple is the extension a file has.
         // The second element of each tuple is the extension that should be used in a path import.
         // e.g. if we want to import file `foo.mts`, we should write `import {} from "./foo.mjs".
@@ -3528,7 +3528,7 @@ namespace ts {
                     if (resolvedModule.isExternalLibraryImport && !resolutionExtensionIsTSOrJson(resolvedModule.extension)) {
                         errorOnImplicitAnyModule(/*isError*/ false, errorNode, resolvedModule, moduleReference);
                     }
-                    if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node12 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
+                    if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node16 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
                         const isSyncImport = (currentSourceFile.impliedNodeFormat === ModuleKind.CommonJS && !findAncestor(location, isImportCall)) || !!findAncestor(location, isImportEqualsDeclaration);
                         const overrideClauseHost = findAncestor(location, l => isImportTypeNode(l) || isExportDeclaration(l) || isImportDeclaration(l)) as ImportTypeNode | ImportDeclaration | ExportDeclaration | undefined;
                         const overrideClause = overrideClauseHost && isImportTypeNode(overrideClauseHost) ? overrideClauseHost.assertions?.assertClause : overrideClauseHost?.assertClause;
@@ -3596,7 +3596,7 @@ namespace ts {
                     const tsExtension = tryExtractTSExtension(moduleReference);
                     const isExtensionlessRelativePathImport = pathIsRelative(moduleReference) && !hasExtension(moduleReference);
                     const moduleResolutionKind = getEmitModuleResolutionKind(compilerOptions);
-                    const resolutionIsNode12OrNext = moduleResolutionKind === ModuleResolutionKind.Node12 ||
+                    const resolutionIsNode16OrNext = moduleResolutionKind === ModuleResolutionKind.Node16 ||
                         moduleResolutionKind === ModuleResolutionKind.NodeNext;
                     if (tsExtension) {
                         const diag = Diagnostics.An_import_path_cannot_end_with_a_0_extension_Consider_importing_1_instead;
@@ -3617,16 +3617,16 @@ namespace ts {
                         hasJsonModuleEmitEnabled(compilerOptions)) {
                         error(errorNode, Diagnostics.Cannot_find_module_0_Consider_using_resolveJsonModule_to_import_module_with_json_extension, moduleReference);
                     }
-                    else if (mode === ModuleKind.ESNext && resolutionIsNode12OrNext && isExtensionlessRelativePathImport) {
+                    else if (mode === ModuleKind.ESNext && resolutionIsNode16OrNext && isExtensionlessRelativePathImport) {
                         const absoluteRef = getNormalizedAbsolutePath(moduleReference, getDirectoryPath(currentSourceFile.path));
                         const suggestedExt = suggestedExtensions.find(([actualExt, _importExt]) => host.fileExists(absoluteRef + actualExt))?.[1];
                         if (suggestedExt) {
                             error(errorNode,
-                                Diagnostics.Relative_import_paths_need_explicit_file_extensions_in_EcmaScript_imports_when_moduleResolution_is_node12_or_nodenext_Did_you_mean_0,
+                                Diagnostics.Relative_import_paths_need_explicit_file_extensions_in_EcmaScript_imports_when_moduleResolution_is_node16_or_nodenext_Did_you_mean_0,
                                 moduleReference + suggestedExt);
                         }
                         else {
-                            error(errorNode, Diagnostics.Relative_import_paths_need_explicit_file_extensions_in_EcmaScript_imports_when_moduleResolution_is_node12_or_nodenext_Consider_adding_an_extension_to_the_import_path);
+                            error(errorNode, Diagnostics.Relative_import_paths_need_explicit_file_extensions_in_EcmaScript_imports_when_moduleResolution_is_node16_or_nodenext_Consider_adding_an_extension_to_the_import_path);
                         }
                     }
                     else {
@@ -6191,7 +6191,7 @@ namespace ts {
                     const targetFile = getSourceFileOfModule(chain[0]);
                     let specifier: string | undefined;
                     let assertion: ImportTypeAssertionContainer | undefined;
-                    if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node12 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
+                    if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node16 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
                         // An `import` type directed at an esm format file is only going to resolve in esm mode - set the esm mode assertion
                         if (targetFile?.impliedNodeFormat === ModuleKind.ESNext && targetFile.impliedNodeFormat !== contextFile?.impliedNodeFormat) {
                             specifier = getSpecifierForModuleSymbol(chain[0], context, ModuleKind.ESNext);
@@ -6208,7 +6208,7 @@ namespace ts {
                     }
                     if (!(context.flags & NodeBuilderFlags.AllowNodeModulesRelativePaths) && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Classic && specifier.indexOf("/node_modules/") >= 0) {
                         const oldSpecifier = specifier;
-                        if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node12 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
+                        if (getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.Node16 || getEmitModuleResolutionKind(compilerOptions) === ModuleResolutionKind.NodeNext) {
                             // We might be able to write a portable import type using a mode override; try specifier generation again, but with a different mode set
                             const swappedMode = contextFile?.impliedNodeFormat === ModuleKind.ESNext ? ModuleKind.CommonJS : ModuleKind.ESNext;
                             specifier = getSpecifierForModuleSymbol(chain[0], context, swappedMode);
@@ -32060,13 +32060,13 @@ namespace ts {
         }
 
         function checkImportMetaProperty(node: MetaProperty) {
-            if (moduleKind === ModuleKind.Node12 || moduleKind === ModuleKind.NodeNext) {
+            if (moduleKind === ModuleKind.Node16 || moduleKind === ModuleKind.NodeNext) {
                 if (getSourceFileOfNode(node).impliedNodeFormat !== ModuleKind.ESNext) {
                     error(node, Diagnostics.The_import_meta_meta_property_is_not_allowed_in_files_which_will_build_into_CommonJS_output);
                 }
             }
             else if (moduleKind < ModuleKind.ES2020 && moduleKind !== ModuleKind.System) {
-                error(node, Diagnostics.The_import_meta_meta_property_is_only_allowed_when_the_module_option_is_es2020_es2022_esnext_system_node12_or_nodenext);
+                error(node, Diagnostics.The_import_meta_meta_property_is_only_allowed_when_the_module_option_is_es2020_es2022_esnext_system_node16_or_nodenext);
             }
             const file = getSourceFileOfNode(node);
             Debug.assert(!!(file.flags & NodeFlags.PossiblyContainsImportMeta), "Containing file is missing import meta node flag.");
@@ -33101,10 +33101,11 @@ namespace ts {
                                 Diagnostics.await_expressions_are_only_allowed_at_the_top_level_of_a_file_when_that_file_is_a_module_but_this_file_has_no_imports_or_exports_Consider_adding_an_empty_export_to_make_this_file_a_module);
                             diagnostics.add(diagnostic);
                         }
-                        if ((moduleKind !== ModuleKind.ES2022 && moduleKind !== ModuleKind.ESNext && moduleKind !== ModuleKind.System && !(moduleKind === ModuleKind.NodeNext && getSourceFileOfNode(node).impliedNodeFormat === ModuleKind.ESNext)) || languageVersion < ScriptTarget.ES2017) {
+                        if ((moduleKind !== ModuleKind.ES2022 && moduleKind !== ModuleKind.ESNext && moduleKind !== ModuleKind.System && !(moduleKind >= ModuleKind.Node16 && getSourceFileOfNode(node).impliedNodeFormat === ModuleKind.ESNext)) || languageVersion < ScriptTarget.ES2017) {
                             span = getSpanOfTokenAtPosition(sourceFile, node.pos);
                             const diagnostic = createFileDiagnostic(sourceFile, span.start, span.length,
-                                Diagnostics.Top_level_await_expressions_are_only_allowed_when_the_module_option_is_set_to_es2022_esnext_system_or_nodenext_and_the_target_option_is_set_to_es2017_or_higher);
+                                // TODO
+                                Diagnostics.Top_level_await_expressions_are_only_allowed_when_the_module_option_is_set_to_es2022_esnext_system_node16_or_nodenext_and_the_target_option_is_set_to_es2017_or_higher);
                             diagnostics.add(diagnostic);
                         }
                     }
@@ -35809,8 +35810,8 @@ namespace ts {
             if (node.assertions) {
                 const override = getResolutionModeOverrideForClause(node.assertions.assertClause, grammarErrorOnNode);
                 if (override) {
-                    if (getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Node12 && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeNext) {
-                        grammarErrorOnNode(node.assertions.assertClause, Diagnostics.Resolution_modes_are_only_supported_when_moduleResolution_is_node12_or_nodenext);
+                    if (getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Node16 && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeNext) {
+                        grammarErrorOnNode(node.assertions.assertClause, Diagnostics.Resolution_modes_are_only_supported_when_moduleResolution_is_node16_or_nodenext);
                     }
                 }
             }
@@ -37428,7 +37429,7 @@ namespace ts {
 
         function checkCollisionWithRequireExportsInGeneratedCode(node: Node, name: Identifier | undefined) {
             // No need to check for require or exports for ES6 modules and later
-            if (moduleKind >= ModuleKind.ES2015 && !(moduleKind >= ModuleKind.Node12 && getSourceFileOfNode(node).impliedNodeFormat === ModuleKind.CommonJS)) {
+            if (moduleKind >= ModuleKind.ES2015 && !(moduleKind >= ModuleKind.Node16 && getSourceFileOfNode(node).impliedNodeFormat === ModuleKind.CommonJS)) {
                 return;
             }
 
@@ -40703,8 +40704,8 @@ namespace ts {
                 const validForTypeAssertions = isExclusivelyTypeOnlyImportOrExport(declaration);
                 const override = getResolutionModeOverrideForClause(declaration.assertClause, validForTypeAssertions ? grammarErrorOnNode : undefined);
                 if (validForTypeAssertions && override) {
-                    if (getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Node12 && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeNext) {
-                        return grammarErrorOnNode(declaration.assertClause, Diagnostics.Resolution_modes_are_only_supported_when_moduleResolution_is_node12_or_nodenext);
+                    if (getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.Node16 && getEmitModuleResolutionKind(compilerOptions) !== ModuleResolutionKind.NodeNext) {
+                        return grammarErrorOnNode(declaration.assertClause, Diagnostics.Resolution_modes_are_only_supported_when_moduleResolution_is_node16_or_nodenext);
                     }
                     return; // Other grammar checks do not apply to type-only imports with resolution mode assertions
                 }
@@ -44173,9 +44174,9 @@ namespace ts {
                                 diagnostics.add(createDiagnosticForNode(forInOrOfStatement.awaitModifier,
                                     Diagnostics.for_await_loops_are_only_allowed_at_the_top_level_of_a_file_when_that_file_is_a_module_but_this_file_has_no_imports_or_exports_Consider_adding_an_empty_export_to_make_this_file_a_module));
                             }
-                            if ((moduleKind !== ModuleKind.ES2022 && moduleKind !== ModuleKind.ESNext && moduleKind !== ModuleKind.System && !(moduleKind === ModuleKind.NodeNext && getSourceFileOfNode(forInOrOfStatement).impliedNodeFormat === ModuleKind.ESNext)) || languageVersion < ScriptTarget.ES2017) {
+                            if ((moduleKind !== ModuleKind.ES2022 && moduleKind !== ModuleKind.ESNext && moduleKind !== ModuleKind.System && !(moduleKind >= ModuleKind.Node16 && getSourceFileOfNode(forInOrOfStatement).impliedNodeFormat === ModuleKind.ESNext)) || languageVersion < ScriptTarget.ES2017) {
                                 diagnostics.add(createDiagnosticForNode(forInOrOfStatement.awaitModifier,
-                                    Diagnostics.Top_level_for_await_loops_are_only_allowed_when_the_module_option_is_set_to_es2022_esnext_system_or_nodenext_and_the_target_option_is_set_to_es2017_or_higher));
+                                    Diagnostics.Top_level_for_await_loops_are_only_allowed_when_the_module_option_is_set_to_es2022_esnext_system_node16_or_nodenext_and_the_target_option_is_set_to_es2017_or_higher));
                             }
                         }
                     }
@@ -44947,7 +44948,7 @@ namespace ts {
 
         function checkGrammarImportCallExpression(node: ImportCall): boolean {
             if (moduleKind === ModuleKind.ES2015) {
-                return grammarErrorOnNode(node, Diagnostics.Dynamic_imports_are_only_supported_when_the_module_flag_is_set_to_es2020_es2022_esnext_commonjs_amd_system_umd_node12_or_nodenext);
+                return grammarErrorOnNode(node, Diagnostics.Dynamic_imports_are_only_supported_when_the_module_flag_is_set_to_es2020_es2022_esnext_commonjs_amd_system_umd_node16_or_nodenext);
             }
 
             if (node.typeArguments) {
@@ -44961,7 +44962,7 @@ namespace ts {
 
                 if (nodeArguments.length > 1) {
                     const assertionArgument = nodeArguments[1];
-                    return grammarErrorOnNode(assertionArgument, Diagnostics.Dynamic_imports_only_support_a_second_argument_when_the_module_option_is_set_to_esnext_or_nodenext);
+                    return grammarErrorOnNode(assertionArgument, Diagnostics.Dynamic_imports_only_support_a_second_argument_when_the_module_option_is_set_to_esnext_node16_or_nodenext);
                 }
             }
 

src/compiler/commandLineParser.ts

@@ -423,7 +423,7 @@ namespace ts {
                 es2020: ModuleKind.ES2020,
                 es2022: ModuleKind.ES2022,
                 esnext: ModuleKind.ESNext,
-                node12: ModuleKind.Node12,
+                node16: ModuleKind.Node16,
                 nodenext: ModuleKind.NodeNext,
             })),
             affectsModuleResolution: true,
@@ -781,7 +781,7 @@ namespace ts {
             type: new Map(getEntries({
                 node: ModuleResolutionKind.NodeJs,
                 classic: ModuleResolutionKind.Classic,
-                node12: ModuleResolutionKind.Node12,
+                node16: ModuleResolutionKind.Node16,
                 nodenext: ModuleResolutionKind.NodeNext,
             })),
             affectsModuleResolution: true,
@@ -1263,7 +1263,7 @@ namespace ts {
             affectsModuleResolution: true,
             description: Diagnostics.Control_what_method_is_used_to_detect_module_format_JS_files,
             category: Diagnostics.Language_and_Environment,
-            defaultValueDescription: Diagnostics.auto_Colon_Treat_files_with_imports_exports_import_meta_jsx_with_jsx_Colon_react_jsx_or_esm_format_with_module_Colon_node12_as_modules,
+            defaultValueDescription: Diagnostics.auto_Colon_Treat_files_with_imports_exports_import_meta_jsx_with_jsx_Colon_react_jsx_or_esm_format_with_module_Colon_node16_as_modules,
         }
     ];