Remove preserveValueImports

src/compiler/checker.ts

@@ -45945,17 +45945,13 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                         case SyntaxKind.ImportClause:
                         case SyntaxKind.ImportSpecifier:
                         case SyntaxKind.ImportEqualsDeclaration: {
-                            if (compilerOptions.preserveValueImports || compilerOptions.verbatimModuleSyntax) {
+                            if (compilerOptions.verbatimModuleSyntax) {
                                 Debug.assertIsDefined(node.name, "An ImportClause with a symbol should have a name");
                                 const message = compilerOptions.verbatimModuleSyntax && isInternalModuleImportEqualsDeclaration(node)
                                     ? Diagnostics.An_import_alias_cannot_resolve_to_a_type_or_type_only_declaration_when_verbatimModuleSyntax_is_enabled
                                     : isType
-                                    ? compilerOptions.verbatimModuleSyntax
-                                        ? Diagnostics._0_is_a_type_and_must_be_imported_using_a_type_only_import_when_verbatimModuleSyntax_is_enabled
-                                        : Diagnostics._0_is_a_type_and_must_be_imported_using_a_type_only_import_when_preserveValueImports_and_isolatedModules_are_both_enabled
-                                    : compilerOptions.verbatimModuleSyntax
-                                    ? Diagnostics._0_resolves_to_a_type_only_declaration_and_must_be_imported_using_a_type_only_import_when_verbatimModuleSyntax_is_enabled
-                                    : Diagnostics._0_resolves_to_a_type_only_declaration_and_must_be_imported_using_a_type_only_import_when_preserveValueImports_and_isolatedModules_are_both_enabled;
+                                    ? Diagnostics._0_is_a_type_and_must_be_imported_using_a_type_only_import_when_verbatimModuleSyntax_is_enabled
+                                    : Diagnostics._0_resolves_to_a_type_only_declaration_and_must_be_imported_using_a_type_only_import_when_verbatimModuleSyntax_is_enabled;
                                 const name = idText(node.kind === SyntaxKind.ImportSpecifier ? node.propertyName || node.name : node.name);
                                 addTypeOnlyDeclarationRelatedInfo(
                                     error(node, message, name),

src/compiler/commandLineParser.ts

@@ -1519,7 +1519,7 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         type: "boolean",
         affectsEmit: true,
         affectsBuildInfo: true,
-        category: Diagnostics.Emit,
+        category: Diagnostics.Backwards_Compatibility,
         description: Diagnostics.Preserve_unused_imported_values_in_the_JavaScript_output_that_would_otherwise_be_removed,
         defaultValueDescription: false,
     },

src/compiler/diagnosticMessages.json

@@ -1468,14 +1468,6 @@
         "category": "Error",
         "code": 1443
     },
-    "'{0}' is a type and must be imported using a type-only import when 'preserveValueImports' and 'isolatedModules' are both enabled.": {
-        "category": "Error",
-        "code": 1444
-    },
-    "'{0}' resolves to a type-only declaration and must be imported using a type-only import when 'preserveValueImports' and 'isolatedModules' are both enabled.": {
-        "category": "Error",
-        "code": 1446
-    },
     "'{0}' resolves to a type-only declaration and must be re-exported using a type-only re-export when '{1}' is enabled.": {
         "category": "Error",
         "code": 1448

src/compiler/program.ts

@@ -4413,18 +4413,11 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
             }
         }
 
-        if (options.preserveValueImports && getEmitModuleKind(options) < ModuleKind.ES2015) {
-            createDiagnosticForOptionName(Diagnostics.Option_0_can_only_be_used_when_module_is_set_to_preserve_or_to_es2015_or_later, "preserveValueImports");
-        }
-
         const moduleKind = getEmitModuleKind(options);
         if (options.verbatimModuleSyntax) {
             if (moduleKind === ModuleKind.AMD || moduleKind === ModuleKind.UMD || moduleKind === ModuleKind.System) {
                 createDiagnosticForOptionName(Diagnostics.Option_verbatimModuleSyntax_cannot_be_used_when_module_is_set_to_UMD_AMD_or_System, "verbatimModuleSyntax");
             }
-            if (options.preserveValueImports) {
-                createRedundantOptionDiagnostic("preserveValueImports", "verbatimModuleSyntax");
-            }
         }
 
         if (options.allowImportingTsExtensions && !(options.noEmit || options.emitDeclarationOnly)) {
@@ -4903,26 +4896,6 @@ export function createProgram(rootNamesOrOptions: readonly string[] | CreateProg
         return needsCompilerDiagnostic;
     }
 
-    /**
-     * Only creates a diagnostic on the option key specified by `errorOnOption`.
-     * If both options are specified in the program in separate config files via `extends`,
-     * a diagnostic is only created if `errorOnOption` is specified in the leaf config file.
-     * Useful if `redundantWithOption` represents a superset of the functionality of `errorOnOption`:
-     * if a user inherits `errorOnOption` from a base config file, it's still valid and useful to
-     * override it in the leaf config file.
-     */
-    function createRedundantOptionDiagnostic(errorOnOption: string, redundantWithOption: string) {
-        const compilerOptionsObjectLiteralSyntax = getCompilerOptionsObjectLiteralSyntax();
-        if (compilerOptionsObjectLiteralSyntax) {
-            // This is a no-op if `errorOnOption` isn't present in the leaf config file.
-            createOptionDiagnosticInObjectLiteralSyntax(compilerOptionsObjectLiteralSyntax, /*onKey*/ true, errorOnOption, /*key2*/ undefined, Diagnostics.Option_0_is_redundant_and_cannot_be_specified_with_option_1, errorOnOption, redundantWithOption);
-        }
-        else {
-            // There was no config file, so both options were specified on the command line.
-            createDiagnosticForOptionName(Diagnostics.Option_0_is_redundant_and_cannot_be_specified_with_option_1, errorOnOption, redundantWithOption);
-        }
-    }
-
     function blockEmittingOfFile(emitFileName: string, diag: Diagnostic) {
         hasEmitBlockingDiagnostics.set(toPath(emitFileName), true);
         programDiagnostics.add(diag);

src/compiler/transformers/ts.ts

@@ -2742,9 +2742,6 @@ export function transformTypeScript(context: TransformationContext) {
     }
 
     function shouldEmitAliasDeclaration(node: Node): boolean {
-        return compilerOptions.verbatimModuleSyntax || isInJSFile(node) ||
-            (compilerOptions.preserveValueImports
-                ? resolver.isValueAliasDeclaration(node)
-                : resolver.isReferencedAliasDeclaration(node));
+        return compilerOptions.verbatimModuleSyntax || isInJSFile(node) || resolver.isReferencedAliasDeclaration(node);
     }
 }

src/compiler/types.ts

@@ -7238,6 +7238,7 @@ export interface CompilerOptions {
     preserveConstEnums?: boolean;
     noImplicitOverride?: boolean;
     preserveSymlinks?: boolean;
+    /** @deprecated */
     preserveValueImports?: boolean;
     /** @internal */ preserveWatchOutput?: boolean;
     project?: string;

src/compiler/utilities.ts

@@ -8885,7 +8885,7 @@ export function hasJsonModuleEmitEnabled(options: CompilerOptions) {
 
 /** @internal */
 export function importNameElisionDisabled(options: CompilerOptions) {
-    return options.verbatimModuleSyntax || options.isolatedModules && options.preserveValueImports;
+    return options.verbatimModuleSyntax;
 }
 
 /** @internal */

src/services/transpile.ts

@@ -47,7 +47,6 @@ export interface TranspileOutput {
 
 const optionsRedundantWithVerbatimModuleSyntax = new Set([
     "isolatedModules",
-    "preserveValueImports",
 ]);
 
 /*

tests/baselines/reference/api/typescript.d.ts

@@ -7602,6 +7602,7 @@ declare namespace ts {
         preserveConstEnums?: boolean;
         noImplicitOverride?: boolean;
         preserveSymlinks?: boolean;
+        /** @deprecated */
         preserveValueImports?: boolean;
         project?: string;
         reactNamespace?: string;

tests/baselines/reference/config/initTSConfig/Default initialized TSConfig/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --help/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with --watch/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with advanced options/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     "declarationDir": "lib",                             /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with boolean value compiler options/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with enum value compiler options/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with files options/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option value/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with incorrect compiler option/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options with enum value/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/config/initTSConfig/Initialized TSConfig with list compiler options/tsconfig.json

@@ -70,7 +70,6 @@
     // "noEmitOnError": true,                            /* Disable emitting files if any type checking errors are reported. */
     // "preserveConstEnums": true,                       /* Disable erasing 'const enum' declarations in generated code. */
     // "declarationDir": "./",                           /* Specify the output directory for generated declaration files. */
-    // "preserveValueImports": true,                     /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
 
     /* Interop Constraints */
     // "isolatedModules": true,                          /* Ensure that each file can be safely transpiled without relying on other imports. */

tests/baselines/reference/preserveValueImports(isolatedmodules=false).js

@@ -31,14 +31,14 @@ export default {};
 export var b = 0;
 export var c = 1;
 //// [b.js]
-import a, { b, c } from "./a";
+export {};
 //// [c.js]
-import * as a from "./a";
+export {};
 //// [d.js]
 export {};
 //// [e.js]
 DD;
 export {};
 //// [f.js]
-import { b, c } from "./a";
+import { b } from "./a";
 b;

tests/baselines/reference/preserveValueImports(isolatedmodules=true).errors.txt

@@ -1,6 +1,5 @@
 error TS5102: Option 'preserveValueImports' has been removed. Please remove it from your configuration.
   Use 'verbatimModuleSyntax' instead.
-b.ts(1,19): error TS1444: 'D' is a type and must be imported using a type-only import when 'preserveValueImports' and 'isolatedModules' are both enabled.
 d.ts(1,1): error TS1203: Export assignment cannot be used when targeting ECMAScript modules. Consider using 'export default' or another module format instead.
 e.ts(1,1): error TS1202: Import assignment cannot be used when targeting ECMAScript modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.
 e.ts(2,1): error TS1202: Import assignment cannot be used when targeting ECMAScript modules. Consider using 'import * as ns from "mod"', 'import {a} from "mod"', 'import d from "mod"', or another module format instead.
@@ -14,10 +13,8 @@ e.ts(2,1): error TS1202: Import assignment cannot be used when targeting ECMAScr
     export const c = 1;
     export interface D {}
 
-==== b.ts (1 errors) ====
+==== b.ts (0 errors) ====
     import a, { b, c, D } from "./a";
-                      ~
-!!! error TS1444: 'D' is a type and must be imported using a type-only import when 'preserveValueImports' and 'isolatedModules' are both enabled.
 
 ==== c.ts (0 errors) ====
     import * as a from "./a";

tests/baselines/reference/preserveValueImports(isolatedmodules=true).js

@@ -31,14 +31,14 @@ export default {};
 export var b = 0;
 export var c = 1;
 //// [b.js]
-import a, { b, c } from "./a";
+export {};
 //// [c.js]
-import * as a from "./a";
+export {};
 //// [d.js]
 export {};
 //// [e.js]
 DD;
 export {};
 //// [f.js]
-import { b, c } from "./a";
+import { b } from "./a";
 b;