Fixed JS emit when downleveling class static blocks on anonymous default-exported class

src/compiler/transformers/classFields.ts

@@ -1911,9 +1911,9 @@ export function transformClassFields(context: TransformationContext): (x: Source
             //      HasLexicalDeclaration (N) : Determines if the argument identifier has a binding in this environment record that was created using
             //                                  a lexical declaration such as a LexicalDeclaration or a ClassDeclaration.
 
-            const staticProperties = getStaticPropertiesAndClassStaticBlock(node);
-            if (some(staticProperties)) {
-                addPropertyOrClassStaticBlockStatements(statements, staticProperties, factory.getInternalName(node));
+            const staticDeclarations = getStaticPropertiesAndClassStaticBlock(node);
+            if (some(staticDeclarations)) {
+                addPropertyOrClassStaticBlockStatements(statements, staticDeclarations, factory.getInternalName(node));
             }
         }
 

src/compiler/transformers/ts.ts

@@ -80,6 +80,7 @@ import {
     isCatchClause,
     isClassElement,
     isClassLike,
+    isClassStaticBlockDeclaration,
     isComputedPropertyName,
     isDecorator,
     isElementAccessExpression,
@@ -221,10 +222,11 @@ const enum ClassFacts {
     HasStaticInitializedProperties = 1 << 0,
     HasClassOrConstructorParameterDecorators = 1 << 1,
     HasMemberDecorators = 1 << 2,
-    IsExportOfNamespace = 1 << 3,
-    IsNamedExternalExport = 1 << 4,
-    IsDefaultExternalExport = 1 << 5,
-    IsDerivedClass = 1 << 6,
+    HasStaticBlocks = 1 << 3,
+    IsExportOfNamespace = 1 << 4,
+    IsNamedExternalExport = 1 << 5,
+    IsDefaultExternalExport = 1 << 6,
+    IsDerivedClass = 1 << 7,
 
     HasAnyDecorators = HasClassOrConstructorParameterDecorators | HasMemberDecorators,
     MayNeedImmediatelyInvokedFunctionExpression = HasAnyDecorators | HasStaticInitializedProperties,
@@ -856,6 +858,7 @@ export function transformTypeScript(context: TransformationContext): Transformer
     function getClassFacts(node: ClassDeclaration) {
         let facts = ClassFacts.None;
         if (some(getProperties(node, /*requireInitializer*/ true, /*isStatic*/ true))) facts |= ClassFacts.HasStaticInitializedProperties;
+        if (node.transformFlags & TransformFlags.ContainsClassFields && some(node.members, isClassStaticBlockDeclaration)) facts |= ClassFacts.HasStaticBlocks;
         const extendsClauseElement = getEffectiveBaseTypeNode(node);
         if (extendsClauseElement && skipOuterExpressions(extendsClauseElement.expression).kind !== SyntaxKind.NullKeyword) facts |= ClassFacts.IsDerivedClass;
         if (classOrConstructorParameterIsDecorated(legacyDecorators, node)) facts |= ClassFacts.HasClassOrConstructorParameterDecorators;
@@ -885,7 +888,8 @@ export function transformTypeScript(context: TransformationContext): Transformer
         if (
             !isClassLikeDeclarationWithTypeScriptSyntax(node) &&
             !classOrConstructorParameterIsDecorated(legacyDecorators, node) &&
-            !isExportOfNamespace(node)
+            !isExportOfNamespace(node) &&
+            !(facts & ClassFacts.HasStaticBlocks && languageVersion < ScriptTarget.ES2022)
         ) {
             return factory.updateClassDeclaration(
                 node,
@@ -916,8 +920,7 @@ export function transformTypeScript(context: TransformationContext): Transformer
         }
 
         const needsName = moveModifiers && !node.name ||
-            facts & ClassFacts.HasMemberDecorators ||
-            facts & ClassFacts.HasStaticInitializedProperties;
+            facts & (ClassFacts.HasMemberDecorators | ClassFacts.HasStaticInitializedProperties | ClassFacts.HasStaticBlocks);
 
         const name = needsName ?
             node.name ?? factory.getGeneratedNameForNode(node) :

tests/baselines/reference/classStaticBlock29(target=es2015).js

@@ -0,0 +1,41 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+//// [classStaticBlock29.ts]
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+  static {
+    this.demo = 1;
+  }
+}
+
+export function makeCls() {
+  return class {
+    static demo: number;
+    static {
+      this.demo = 1;
+    }
+  };
+}
+
+
+//// [classStaticBlock29.js]
+// https://github.com/microsoft/TypeScript/issues/60879
+var _a;
+class default_1 {
+}
+_a = default_1;
+(() => {
+    _a.demo = 1;
+})();
+export default default_1;
+export function makeCls() {
+    var _b;
+    return _b = class {
+        },
+        (() => {
+            _b.demo = 1;
+        })(),
+        _b;
+}

tests/baselines/reference/classStaticBlock29(target=es2015).symbols

@@ -0,0 +1,33 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+=== classStaticBlock29.ts ===
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+>demo : Symbol(default.demo, Decl(classStaticBlock29.ts, 2, 22))
+
+  static {
+    this.demo = 1;
+>this.demo : Symbol(default.demo, Decl(classStaticBlock29.ts, 2, 22))
+>this : Symbol(default, Decl(classStaticBlock29.ts, 0, 0))
+>demo : Symbol(default.demo, Decl(classStaticBlock29.ts, 2, 22))
+  }
+}
+
+export function makeCls() {
+>makeCls : Symbol(makeCls, Decl(classStaticBlock29.ts, 7, 1))
+
+  return class {
+    static demo: number;
+>demo : Symbol((Anonymous class).demo, Decl(classStaticBlock29.ts, 10, 16))
+
+    static {
+      this.demo = 1;
+>this.demo : Symbol((Anonymous class).demo, Decl(classStaticBlock29.ts, 10, 16))
+>this : Symbol((Anonymous class), Decl(classStaticBlock29.ts, 10, 8))
+>demo : Symbol((Anonymous class).demo, Decl(classStaticBlock29.ts, 10, 16))
+    }
+  };
+}
+

tests/baselines/reference/classStaticBlock29(target=es2015).types

@@ -0,0 +1,53 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+=== classStaticBlock29.ts ===
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+>demo : number
+>     : ^^^^^^
+
+  static {
+    this.demo = 1;
+>this.demo = 1 : 1
+>              : ^
+>this.demo : number
+>          : ^^^^^^
+>this : typeof default
+>     : ^^^^^^^^^^^^^^
+>demo : number
+>     : ^^^^^^
+>1 : 1
+>  : ^
+  }
+}
+
+export function makeCls() {
+>makeCls : () => typeof (Anonymous class)
+>        : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+  return class {
+>class {    static demo: number;    static {      this.demo = 1;    }  } : typeof (Anonymous class)
+>                                                                        : ^^^^^^^^^^^^^^^^^^^^^^^^
+
+    static demo: number;
+>demo : number
+>     : ^^^^^^
+
+    static {
+      this.demo = 1;
+>this.demo = 1 : 1
+>              : ^
+>this.demo : number
+>          : ^^^^^^
+>this : typeof (Anonymous class)
+>     : ^^^^^^^^^^^^^^^^^^^^^^^^
+>demo : number
+>     : ^^^^^^
+>1 : 1
+>  : ^
+    }
+  };
+}
+

tests/baselines/reference/classStaticBlock29(target=es2022).js

@@ -0,0 +1,38 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+//// [classStaticBlock29.ts]
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+  static {
+    this.demo = 1;
+  }
+}
+
+export function makeCls() {
+  return class {
+    static demo: number;
+    static {
+      this.demo = 1;
+    }
+  };
+}
+
+
+//// [classStaticBlock29.js]
+// https://github.com/microsoft/TypeScript/issues/60879
+export default class {
+    static demo;
+    static {
+        this.demo = 1;
+    }
+}
+export function makeCls() {
+    return class {
+        static demo;
+        static {
+            this.demo = 1;
+        }
+    };
+}

tests/baselines/reference/classStaticBlock29(target=es2022).symbols

@@ -0,0 +1,33 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+=== classStaticBlock29.ts ===
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+>demo : Symbol(default.demo, Decl(classStaticBlock29.ts, 2, 22))
+
+  static {
+    this.demo = 1;
+>this.demo : Symbol(default.demo, Decl(classStaticBlock29.ts, 2, 22))
+>this : Symbol(default, Decl(classStaticBlock29.ts, 0, 0))
+>demo : Symbol(default.demo, Decl(classStaticBlock29.ts, 2, 22))
+  }
+}
+
+export function makeCls() {
+>makeCls : Symbol(makeCls, Decl(classStaticBlock29.ts, 7, 1))
+
+  return class {
+    static demo: number;
+>demo : Symbol((Anonymous class).demo, Decl(classStaticBlock29.ts, 10, 16))
+
+    static {
+      this.demo = 1;
+>this.demo : Symbol((Anonymous class).demo, Decl(classStaticBlock29.ts, 10, 16))
+>this : Symbol((Anonymous class), Decl(classStaticBlock29.ts, 10, 8))
+>demo : Symbol((Anonymous class).demo, Decl(classStaticBlock29.ts, 10, 16))
+    }
+  };
+}
+

tests/baselines/reference/classStaticBlock29(target=es2022).types

@@ -0,0 +1,53 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+=== classStaticBlock29.ts ===
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+>demo : number
+>     : ^^^^^^
+
+  static {
+    this.demo = 1;
+>this.demo = 1 : 1
+>              : ^
+>this.demo : number
+>          : ^^^^^^
+>this : typeof default
+>     : ^^^^^^^^^^^^^^
+>demo : number
+>     : ^^^^^^
+>1 : 1
+>  : ^
+  }
+}
+
+export function makeCls() {
+>makeCls : () => typeof (Anonymous class)
+>        : ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+  return class {
+>class {    static demo: number;    static {      this.demo = 1;    }  } : typeof (Anonymous class)
+>                                                                        : ^^^^^^^^^^^^^^^^^^^^^^^^
+
+    static demo: number;
+>demo : number
+>     : ^^^^^^
+
+    static {
+      this.demo = 1;
+>this.demo = 1 : 1
+>              : ^
+>this.demo : number
+>          : ^^^^^^
+>this : typeof (Anonymous class)
+>     : ^^^^^^^^^^^^^^^^^^^^^^^^
+>demo : number
+>     : ^^^^^^
+>1 : 1
+>  : ^
+    }
+  };
+}
+

tests/baselines/reference/classStaticBlock29(target=es5).js

@@ -0,0 +1,50 @@
+//// [tests/cases/conformance/classes/classStaticBlock/classStaticBlock29.ts] ////
+
+//// [classStaticBlock29.ts]
+// https://github.com/microsoft/TypeScript/issues/60879
+
+export default class {
+  static demo: number;
+  static {
+    this.demo = 1;
+  }
+}
+
+export function makeCls() {
+  return class {
+    static demo: number;
+    static {
+      this.demo = 1;
+    }
+  };
+}
+
+
+//// [classStaticBlock29.js]
+"use strict";
+// https://github.com/microsoft/TypeScript/issues/60879
+var _a;
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.makeCls = makeCls;
+var default_1 = /** @class */ (function () {
+    function default_1() {
+    }
+    return default_1;
+}());
+_a = default_1;
+(function () {
+    _a.demo = 1;
+})();
+exports.default = default_1;
+function makeCls() {
+    var _b;
+    return _b = /** @class */ (function () {
+            function class_1() {
+            }
+            return class_1;
+        }()),
+        (function () {
+            _b.demo = 1;
+        })(),
+        _b;
+}