Deprecate alwaysStrict: false in TypeScript 6.0

src/compiler/binder.ts

@@ -82,6 +82,7 @@ import {
     FunctionExpression,
     FunctionLikeDeclaration,
     GetAccessorDeclaration,
+    getAlwaysStrict,
     getAssignedExpandoInitializer,
     getAssignmentDeclarationKind,
     getAssignmentDeclarationPropertyAccessKind,
@@ -108,7 +109,6 @@ import {
     getSourceFileOfNode,
     getSourceTextOfNodeFromSourceFile,
     getSpanOfTokenAtPosition,
-    getStrictOptionValue,
     getSymbolNameForPrivateIdentifier,
     getTextOfIdentifierOrLiteral,
     getThisContainer,
@@ -617,7 +617,7 @@ function createBinder(): (file: SourceFile, options: CompilerOptions) => void {
     }
 
     function bindInStrictMode(file: SourceFile, opts: CompilerOptions): boolean {
-        if (getStrictOptionValue(opts, "alwaysStrict") && !file.isDeclarationFile) {
+        if (getAlwaysStrict(opts) && !file.isDeclarationFile) {
             // bind in strict mode source files with alwaysStrict option
             return true;
         }

src/compiler/commandLineParser.ts

@@ -987,10 +987,9 @@ const commandOptionsWithoutBuild: CommandLineOption[] = [
         affectsSourceFile: true,
         affectsEmit: true,
         affectsBuildInfo: true,
-        strictFlag: true,
         category: Diagnostics.Type_Checking,
         description: Diagnostics.Ensure_use_strict_is_always_emitted,
-        defaultValueDescription: Diagnostics.false_unless_strict_is_set,
+        defaultValueDescription: true,
     },
 
     // Additional Checks

src/compiler/program.ts

@@ -4526,6 +4526,9 @@ export function createProgram(_rootNamesOrOptions: readonly string[] | CreatePro
         });
 
         checkDeprecations("6.0", "7.0", createDiagnostic, createDeprecatedDiagnostic => {
+            if (options.alwaysStrict === false) {
+                createDeprecatedDiagnostic("alwaysStrict", "false", /*useInstead*/ undefined, /*related*/ undefined);
+            }
             if (options.moduleResolution === ModuleResolutionKind.Node10) {
                 createDeprecatedDiagnostic("moduleResolution", "node10", /*useInstead*/ undefined, Diagnostics.Visit_https_Colon_Slash_Slashaka_ms_Slashts6_for_migration_information);
             }

src/compiler/transformers/module/module.ts

@@ -41,6 +41,7 @@ import {
     FunctionDeclaration,
     FunctionExpression,
     GeneratedIdentifierFlags,
+    getAlwaysStrict,
     getEmitFlags,
     getEmitModuleKind,
     getEmitScriptTarget,
@@ -55,7 +56,6 @@ import {
     getNamespaceDeclarationNode,
     getNodeId,
     getOriginalNodeId,
-    getStrictOptionValue,
     getTextOfIdentifierOrLiteral,
     hasJSFileExtension,
     hasJsonModuleEmitEnabled,
@@ -277,7 +277,7 @@ export function transformModule(context: TransformationContext): (x: SourceFile
         startLexicalEnvironment();
 
         const statements: Statement[] = [];
-        const ensureUseStrict = getStrictOptionValue(compilerOptions, "alwaysStrict") || isExternalModule(currentSourceFile);
+        const ensureUseStrict = getAlwaysStrict(compilerOptions) || isExternalModule(currentSourceFile);
         const statementOffset = factory.copyPrologue(node.statements, statements, ensureUseStrict && !isJsonSourceFile(node), topLevelVisitor);
 
         if (shouldEmitUnderscoreUnderscoreESModule()) {

src/compiler/transformers/module/system.ts

@@ -33,14 +33,14 @@ import {
     ForOfStatement,
     ForStatement,
     FunctionDeclaration,
+    getAlwaysStrict,
     getEmitFlags,
     getExternalHelpersModuleName,
     getExternalModuleNameLiteral,
     getLocalNameForExternalImport,
     getNodeId,
     getOriginalNode,
     getOriginalNodeId,
-    getStrictOptionValue,
     getTextOfIdentifierOrLiteral,
     hasSyntacticModifier,
     Identifier,
@@ -357,7 +357,7 @@ export function transformSystemModule(context: TransformationContext): (x: Sourc
         startLexicalEnvironment();
 
         // Add any prologue directives.
-        const ensureUseStrict = getStrictOptionValue(compilerOptions, "alwaysStrict") || isExternalModule(currentSourceFile);
+        const ensureUseStrict = getAlwaysStrict(compilerOptions) || isExternalModule(currentSourceFile);
         const statementOffset = factory.copyPrologue(node.statements, statements, ensureUseStrict, topLevelVisitor);
 
         // var __moduleName = context_1 && context_1.id;

src/compiler/transformers/ts.ts

@@ -47,6 +47,7 @@ import {
     FunctionExpression,
     FunctionLikeDeclaration,
     GetAccessorDeclaration,
+    getAlwaysStrict,
     getEffectiveBaseTypeNode,
     getEmitFlags,
     getEmitModuleKind,
@@ -57,7 +58,6 @@ import {
     getOriginalNode,
     getParseTreeNode,
     getProperties,
-    getStrictOptionValue,
     getTextOfNode,
     hasDecorators,
     hasSyntacticModifier,
@@ -836,7 +836,7 @@ export function transformTypeScript(context: TransformationContext): Transformer
     }
 
     function visitSourceFile(node: SourceFile) {
-        const alwaysStrict = getStrictOptionValue(compilerOptions, "alwaysStrict") &&
+        const alwaysStrict = getAlwaysStrict(compilerOptions) &&
             !(isExternalModule(node) && moduleKind >= ModuleKind.ES2015) &&
             !isJsonSourceFile(node);
 

src/compiler/utilities.ts

@@ -2132,7 +2132,7 @@ export function isEffectiveStrictModeSourceFile(node: SourceFile, compilerOption
         return false;
     }
     // If `alwaysStrict` is set, then treat the file as strict.
-    if (getStrictOptionValue(compilerOptions, "alwaysStrict")) {
+    if (getAlwaysStrict(compilerOptions)) {
         return true;
     }
     // Starting with a "use strict" directive indicates the file is strict.
@@ -9203,10 +9203,11 @@ const _computedOptions = createComputedCompilerOptions({
             return getStrictOptionValue(compilerOptions, "strictBuiltinIteratorReturn");
         },
     },
+    // Previously a strict-mode flag, but no longer.
     alwaysStrict: {
-        dependencies: ["strict"],
+        dependencies: [],
         computeValue: compilerOptions => {
-            return getStrictOptionValue(compilerOptions, "alwaysStrict");
+            return compilerOptions.alwaysStrict !== false;
         },
     },
     useUnknownInCatchVariables: {
@@ -9254,6 +9255,8 @@ export const getAreDeclarationMapsEnabled: (compilerOptions: CompilerOptions) =>
 export const getAllowJSCompilerOption: (compilerOptions: CompilerOptions) => boolean = _computedOptions.allowJs.computeValue;
 /** @internal */
 export const getUseDefineForClassFields: (compilerOptions: CompilerOptions) => boolean = _computedOptions.useDefineForClassFields.computeValue;
+/** @internal */
+export const getAlwaysStrict: (compilerOptions: CompilerOptions) => boolean = _computedOptions.alwaysStrict.computeValue;
 
 /** @internal */
 export function emitModuleKindIsNonNodeESM(moduleKind: ModuleKind): boolean {
@@ -9296,7 +9299,6 @@ export type StrictOptionName =
     | "strictBindCallApply"
     | "strictPropertyInitialization"
     | "strictBuiltinIteratorReturn"
-    | "alwaysStrict"
     | "useUnknownInCatchVariables";
 
 /** @internal */

src/testRunner/unittests/tscWatch/programUpdates.ts

@@ -1600,7 +1600,7 @@ foo().hello`,
             },
             {
                 caption: "Set always strict false",
-                edit: sys => sys.writeFile(`/user/username/projects/myproject/tsconfig.json`, jsonToReadableText({ compilerOptions: { strict: true, alwaysStrict: false } })), // Avoid changing 'alwaysStrict' or must re-bind
+                edit: sys => sys.writeFile(`/user/username/projects/myproject/tsconfig.json`, jsonToReadableText({ compilerOptions: { strict: true, alwaysStrict: false, ignoreDeprecations: "6.0" } })), // Avoid changing 'alwaysStrict' or must re-bind
                 timeouts: sys => sys.runQueuedTimeoutCallbacks(),
             },
             {

tests/baselines/reference/2dArrays.js

@@ -18,6 +18,7 @@ class Board {
 }
 
 //// [2dArrays.js]
+"use strict";
 var Cell = /** @class */ (function () {
     function Cell() {
     }

tests/baselines/reference/AmbientModuleAndAmbientFunctionWithTheSameNameAndCommonRoot.js

@@ -14,6 +14,7 @@ var cl = Point();
 var cl = Point.Origin;
 
 //// [test.js]
+"use strict";
 var cl;
 var cl = Point();
 var cl = Point.Origin;

tests/baselines/reference/AmbientModuleAndAmbientWithSameNameAndCommonRoot.js

@@ -26,6 +26,7 @@ var p = new A.Point(0, 0); // unexpected error here, bug 840000
 
 
 //// [test.js]
+"use strict";
 var p;
 var p = A.Point.Origin;
 var p = new A.Point(0, 0); // unexpected error here, bug 840000

tests/baselines/reference/AmbientModuleAndNonAmbientClassWithSameNameAndCommonRoot.js

@@ -23,6 +23,7 @@ var p = A.Point.Origin;
 var p = new A.Point(0, 0); // unexpected error here, bug 840000
 
 //// [classPoint.js]
+"use strict";
 var A;
 (function (A) {
     var Point = /** @class */ (function () {
@@ -35,6 +36,7 @@ var A;
     A.Point = Point;
 })(A || (A = {}));
 //// [test.js]
+"use strict";
 var p;
 var p = A.Point.Origin;
 var p = new A.Point(0, 0); // unexpected error here, bug 840000

tests/baselines/reference/AmbientModuleAndNonAmbientFunctionWithTheSameNameAndCommonRoot.js

@@ -16,10 +16,12 @@ var cl = Point();
 var cl = Point.Origin;
 
 //// [function.js]
+"use strict";
 function Point() {
     return { x: 0, y: 0 };
 }
 //// [test.js]
+"use strict";
 var cl;
 var cl = Point();
 var cl = Point.Origin;

tests/baselines/reference/ArrowFunction1.js

@@ -6,5 +6,6 @@ var v = (a: ) => {
 };
 
 //// [ArrowFunction1.js]
+"use strict";
 var v = function (a) {
 };

tests/baselines/reference/ArrowFunction3.js

@@ -6,6 +6,7 @@ var v = (a): => {
 };
 
 //// [ArrowFunction3.js]
+"use strict";
 var v = (a);
 {
 }

tests/baselines/reference/ArrowFunction4.js

@@ -6,5 +6,6 @@ var v = (a, b) => {
 };
 
 //// [ArrowFunction4.js]
+"use strict";
 var v = function (a, b) {
 };

tests/baselines/reference/ArrowFunctionExpression1.js

@@ -4,4 +4,5 @@
 var v = (public x: string) => { };
 
 //// [ArrowFunctionExpression1.js]
+"use strict";
 var v = function (x) { };

tests/baselines/reference/ClassAndModuleThatMergeWithModuleMemberThatUsesClassTypeParameter.js

@@ -52,6 +52,7 @@ namespace clodule4 {
 
 
 //// [ClassAndModuleThatMergeWithModuleMemberThatUsesClassTypeParameter.js]
+"use strict";
 // all expected to be errors
 var clodule1 = /** @class */ (function () {
     function clodule1() {

tests/baselines/reference/ClassAndModuleThatMergeWithModulesExportedGenericFunctionAndGenericClassStaticFunctionOfTheSameName.js

@@ -18,6 +18,7 @@ namespace clodule {
 
 
 //// [ClassAndModuleThatMergeWithModulesExportedGenericFunctionAndGenericClassStaticFunctionOfTheSameName.js]
+"use strict";
 var clodule = /** @class */ (function () {
     function clodule() {
     }

tests/baselines/reference/ClassAndModuleThatMergeWithModulesExportedGenericFunctionAndNonGenericClassStaticFunctionOfTheSameName.js

@@ -18,6 +18,7 @@ namespace clodule {
 
 
 //// [ClassAndModuleThatMergeWithModulesExportedGenericFunctionAndNonGenericClassStaticFunctionOfTheSameName.js]
+"use strict";
 var clodule = /** @class */ (function () {
     function clodule() {
     }

tests/baselines/reference/ClassAndModuleThatMergeWithModulesExportedStaticFunctionUsingClassPrivateStatics.js

@@ -18,6 +18,7 @@ namespace clodule {
 
 
 //// [ClassAndModuleThatMergeWithModulesExportedStaticFunctionUsingClassPrivateStatics.js]
+"use strict";
 var clodule = /** @class */ (function () {
     function clodule() {
     }

tests/baselines/reference/ClassAndModuleThatMergeWithStaticFunctionAndExportedFunctionThatShareAName.js

@@ -25,6 +25,7 @@ namespace A {
 }
 
 //// [ClassAndModuleThatMergeWithStaticFunctionAndExportedFunctionThatShareAName.js]
+"use strict";
 var Point = /** @class */ (function () {
     function Point(x, y) {
         this.x = x;

tests/baselines/reference/ClassAndModuleThatMergeWithStaticFunctionAndNonExportedFunctionThatShareAName.js

@@ -25,6 +25,7 @@ namespace A {
 }
 
 //// [ClassAndModuleThatMergeWithStaticFunctionAndNonExportedFunctionThatShareAName.js]
+"use strict";
 var Point = /** @class */ (function () {
     function Point(x, y) {
         this.x = x;

tests/baselines/reference/ClassAndModuleThatMergeWithStaticVariableAndExportedVarThatShareAName.js

@@ -25,6 +25,7 @@ namespace A {
 }
 
 //// [ClassAndModuleThatMergeWithStaticVariableAndExportedVarThatShareAName.js]
+"use strict";
 var Point = /** @class */ (function () {
     function Point(x, y) {
         this.x = x;

tests/baselines/reference/ClassAndModuleThatMergeWithStaticVariableAndNonExportedVarThatShareAName.js

@@ -25,6 +25,7 @@ namespace A {
 }
 
 //// [ClassAndModuleThatMergeWithStaticVariableAndNonExportedVarThatShareAName.js]
+"use strict";
 var Point = /** @class */ (function () {
     function Point(x, y) {
         this.x = x;

tests/baselines/reference/ClassAndModuleThatMergeWithStringIndexerAndExportedFunctionWithTypeIncompatibleWithIndexer.js

@@ -4,3 +4,4 @@
 
 
 //// [ClassAndModuleThatMergeWithStringIndexerAndExportedFunctionWithTypeIncompatibleWithIndexer.js]
+"use strict";

tests/baselines/reference/ClassAndModuleWithSameNameAndCommonRoot.js

@@ -41,6 +41,7 @@ var a: { id: string };
 
 
 //// [class.js]
+"use strict";
 var X;
 (function (X) {
     var Y;
@@ -56,6 +57,7 @@ var X;
     })(Y = X.Y || (X.Y = {}));
 })(X || (X = {}));
 //// [module.js]
+"use strict";
 var X;
 (function (X) {
     var Y;
@@ -67,10 +69,12 @@ var X;
     })(Y = X.Y || (X.Y = {}));
 })(X || (X = {}));
 //// [test.js]
+"use strict";
 //var cl: { x: number; y: number; }
 var cl = new X.Y.Point(1, 1);
 var cl = X.Y.Point.Origin; // error not expected here same as bug 83996 ?
 //// [simple.js]
+"use strict";
 var A = /** @class */ (function () {
     function A() {
     }

tests/baselines/reference/ClassAndModuleWithSameNameAndCommonRootES6.js

@@ -41,6 +41,7 @@ var a: { id: string };
 
 
 //// [class.js]
+"use strict";
 var X;
 (function (X) {
     var Y;
@@ -55,6 +56,7 @@ var X;
     })(Y = X.Y || (X.Y = {}));
 })(X || (X = {}));
 //// [module.js]
+"use strict";
 var X;
 (function (X) {
     var Y;
@@ -66,10 +68,12 @@ var X;
     })(Y = X.Y || (X.Y = {}));
 })(X || (X = {}));
 //// [test.js]
+"use strict";
 //var cl: { x: number; y: number; }
 var cl = new X.Y.Point(1, 1);
 var cl = X.Y.Point.Origin; // error not expected here same as bug 83996 ?
 //// [simple.js]
+"use strict";
 class A {
 }
 (function (A) {

tests/baselines/reference/ClassDeclaration10.js

@@ -7,6 +7,7 @@ class C {
 }
 
 //// [ClassDeclaration10.js]
+"use strict";
 var C = /** @class */ (function () {
     function C() {
     }

tests/baselines/reference/ClassDeclaration11.js

@@ -7,6 +7,7 @@ class C {
 }
 
 //// [ClassDeclaration11.js]
+"use strict";
 var C = /** @class */ (function () {
     function C() {
     }