Add module: es2020 (#33893)

src/compiler/checker.ts

@@ -31598,7 +31598,7 @@ namespace ts {
          */
         function checkClassNameCollisionWithObject(name: Identifier): void {
             if (languageVersion === ScriptTarget.ES5 && name.escapedText === "Object"
-                && moduleKind !== ModuleKind.ES2015 && moduleKind !== ModuleKind.ESNext) {
+                && moduleKind < ModuleKind.ES2015) {
                 error(name, Diagnostics.Class_name_cannot_be_Object_when_targeting_ES5_with_module_0, ModuleKind[moduleKind]); // https://github.com/Microsoft/TypeScript/issues/17494
             }
         }
@@ -32763,7 +32763,7 @@ namespace ts {
                         error(node.moduleSpecifier, Diagnostics.Module_0_uses_export_and_cannot_be_used_with_export_Asterisk, symbolToString(moduleSymbol));
                     }
 
-                    if (moduleKind !== ModuleKind.System && moduleKind !== ModuleKind.ES2015 && moduleKind !== ModuleKind.ESNext) {
+                    if (moduleKind !== ModuleKind.System && moduleKind < ModuleKind.ES2015) {
                         checkExternalEmitHelpers(node, ExternalEmitHelpers.ExportStar);
                     }
                 }
@@ -35977,7 +35977,9 @@ namespace ts {
                 return grammarErrorOnNode(node.exclamationToken, Diagnostics.Definite_assignment_assertions_can_only_be_used_along_with_a_type_annotation);
             }
 
-            if (compilerOptions.module !== ModuleKind.ES2015 && compilerOptions.module !== ModuleKind.ESNext && compilerOptions.module !== ModuleKind.System && !compilerOptions.noEmit &&
+            const moduleKind = getEmitModuleKind(compilerOptions);
+
+            if (moduleKind < ModuleKind.ES2015 && moduleKind !== ModuleKind.System && !compilerOptions.noEmit &&
                 !(node.parent.parent.flags & NodeFlags.Ambient) && hasModifier(node.parent.parent, ModifierFlags.Export)) {
                 checkESModuleMarker(node.name);
             }
@@ -36323,7 +36325,7 @@ 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_esnext_commonjs_amd_system_or_umd);
+                return grammarErrorOnNode(node, Diagnostics.Dynamic_imports_are_only_supported_when_the_module_flag_is_set_to_es2020_esnext_commonjs_amd_system_or_umd);
             }
 
             if (node.typeArguments) {

src/compiler/commandLineParser.ts

@@ -304,6 +304,7 @@ namespace ts {
                 umd: ModuleKind.UMD,
                 es6: ModuleKind.ES2015,
                 es2015: ModuleKind.ES2015,
+                es2020: ModuleKind.ES2020,
                 esnext: ModuleKind.ESNext
             }),
             affectsModuleResolution: true,

src/compiler/diagnosticMessages.json

@@ -911,7 +911,7 @@
         "category": "Error",
         "code": 1322
     },
-    "Dynamic imports are only supported when the '--module' flag is set to 'esnext', 'commonjs',  'amd', 'system', or 'umd'.": {
+    "Dynamic imports are only supported when the '--module' flag is set to 'es2020', 'esnext', 'commonjs', 'amd', 'system', or 'umd'.": {
         "category": "Error",
         "code": 1323
     },

src/compiler/factory.ts

@@ -1509,8 +1509,7 @@ namespace ts {
             const moduleKind = getEmitModuleKind(compilerOptions);
             let create = (hasExportStarsToExportValues || (compilerOptions.esModuleInterop && hasImportStarOrImportDefault))
                 && moduleKind !== ModuleKind.System
-                && moduleKind !== ModuleKind.ES2015
-                && moduleKind !== ModuleKind.ESNext;
+                && moduleKind < ModuleKind.ES2015;
             if (!create) {
                 const helpers = getEmitHelpers(node);
                 if (helpers) {

src/compiler/transformer.ts

@@ -3,6 +3,7 @@ namespace ts {
     function getModuleTransformer(moduleKind: ModuleKind): TransformerFactory<SourceFile | Bundle> {
         switch (moduleKind) {
             case ModuleKind.ESNext:
+            case ModuleKind.ES2020:
             case ModuleKind.ES2015:
                 return transformECMAScriptModule;
             case ModuleKind.System:

src/compiler/transformers/ts.ts

@@ -2473,6 +2473,7 @@ namespace ts {
             return isExportOfNamespace(node)
                 || (isExternalModuleExport(node)
                     && moduleKind !== ModuleKind.ES2015
+                    && moduleKind !== ModuleKind.ES2020
                     && moduleKind !== ModuleKind.ESNext
                     && moduleKind !== ModuleKind.System);
         }

src/compiler/types.ts

@@ -5125,6 +5125,7 @@ namespace ts {
         //       Non-ES module kinds should not come between ES2015 (the earliest ES module kind) and ESNext (the last ES
         //       module kind).
         ES2015 = 5,
+        ES2020 = 6,
         ESNext = 99
     }
 

src/compiler/utilities.ts

@@ -5184,6 +5184,7 @@ namespace ts {
             case ModuleKind.CommonJS:
             case ModuleKind.AMD:
             case ModuleKind.ES2015:
+            case ModuleKind.ES2020:
             case ModuleKind.ESNext:
                 return true;
             default: