Fix declaration emit to remove non-JSDoc comments while preserving JSDoc

internal/transformers/declarations/transform.go

@@ -741,14 +741,21 @@
 	if ast.IsPrivateIdentifier(input.Name()) {
 		return nil
 	}
-	return tx.Factory().UpdatePropertyDeclaration(
+	result := tx.Factory().UpdatePropertyDeclaration(
 		input,
 		tx.ensureModifiers(input.AsNode()),
 		input.Name(),
 		input.PostfixToken,
 		tx.ensureType(input.AsNode(), false),
 		tx.ensureNoInitializer(input.AsNode()),
 	)
+	// Only remove all comments if there's no JSDoc to preserve
+	if input.AsNode().Flags&ast.NodeFlagsHasJSDoc == 0 {
+		tx.removeAllComments(result)
+	} else {
+		tx.preserveJsDoc(result, input.AsNode())
+	}
+	return result
 }
 
 func (tx *DeclarationTransformer) transformSetAccessorDeclaration(input *ast.SetAccessorDeclaration) *ast.Node {
@@ -794,7 +801,7 @@
 			newParams = append(newParams, tx.ensureParameter(thisParam.AsParameterDeclaration()))
 		}
 	}
 	if ast.IsSetAccessorDeclaration(input) {
 		var valueParam *ast.Node
 		if !isPrivate {
 			if len(newParams) == 1 && len(input.AsSetAccessorDeclaration().Parameters.Nodes) >= 2 {
@@ -883,7 +890,7 @@
 	} else if ast.IsPrivateIdentifier(input.Name()) {
 		return nil
 	} else {
-		return tx.Factory().UpdateMethodDeclaration(
+		result := tx.Factory().UpdateMethodDeclaration(
 			input,
 			tx.ensureModifiers(input.AsNode()),
 			nil,
@@ -895,6 +902,13 @@
 			nil,
 			nil,
 		)
+		// Only remove all comments if there's no JSDoc to preserve
+		if input.AsNode().Flags&ast.NodeFlagsHasJSDoc == 0 {
+			tx.removeAllComments(result)
+		} else {
+			tx.preserveJsDoc(result, input.AsNode())
+		}
+		return result
 	}
 }
 
@@ -984,11 +998,38 @@
 }
 
 func (tx *DeclarationTransformer) preserveJsDoc(updated *ast.Node, original *ast.Node) {
-	// !!! TODO: JSDoc comment support
-	// if (hasJSDocNodes(updated) && hasJSDocNodes(original)) {
-	// 	updated.jsDoc = original.jsDoc;
-	// }
-	// return setCommentRange(updated, getCommentRange(original));
+	// Get the source file to access JSDoc cache
+	sourceFile := tx.state.currentSourceFile
+	if sourceFile == nil {
+		return
+	}
+
+	// Check if original node has JSDoc comments
+	if original.Flags&ast.NodeFlagsHasJSDoc == 0 {
+		return
+	}
+
+	// Get JSDoc from original node
+	jsdoc := original.JSDoc(sourceFile)
+	if len(jsdoc) == 0 {
+		return
+	}
+
+	// Copy JSDoc to the updated node
+	cache := sourceFile.JSDocCache()
+	if cache == nil {
+		cache = make(map[*ast.Node][]*ast.Node)
+		sourceFile.SetJSDocCache(cache)
+	}
+
+	// Set JSDoc on the updated node
+	cache[updated] = jsdoc
+	updated.Flags |= ast.NodeFlagsHasJSDoc
+
+	// If there was a deprecated tag, preserve that too
+	if original.Flags&ast.NodeFlagsDeprecated != 0 {
+		updated.Flags |= ast.NodeFlagsDeprecated
+	}
 }
 
 func (tx *DeclarationTransformer) removeAllComments(node *ast.Node) {
@@ -1383,27 +1424,42 @@
 		}
 		heritageClauses := tx.Factory().NewNodeList(heritageList)
 
+		classDecl := tx.Factory().UpdateClassDeclaration(
+			input,
+			modifiers,
+			input.Name(),
+			typeParameters,
+			heritageClauses,
+			members,
+		)
+		// Only remove all comments if there's no JSDoc to preserve
+		if input.AsNode().Flags&ast.NodeFlagsHasJSDoc == 0 {
+			tx.removeAllComments(classDecl)
+		} else {
+			tx.preserveJsDoc(classDecl, input.AsNode())
+		}
+
 		return tx.Factory().NewSyntaxList([]*ast.Node{
 			statement,
-			tx.Factory().UpdateClassDeclaration(
-				input,
-				modifiers,
-				input.Name(),
-				typeParameters,
-				heritageClauses,
-				members,
-			),
+			classDecl,
 		})
 	}
 
-	return tx.Factory().UpdateClassDeclaration(
+	result := tx.Factory().UpdateClassDeclaration(
 		input,
 		modifiers,
 		input.Name(),
 		typeParameters,
 		tx.Visitor().VisitNodes(input.HeritageClauses),
 		members,
 	)
+	// Only remove all comments if there's no JSDoc to preserve
+	if input.AsNode().Flags&ast.NodeFlagsHasJSDoc == 0 {
+		tx.removeAllComments(result)
+	} else {
+		tx.preserveJsDoc(result, input.AsNode())
+	}
+	return result
 }
 
 func (tx *DeclarationTransformer) transformVariableStatement(input *ast.VariableStatement) *ast.Node {

testdata/baselines/reference/compiler/declarationEmitCommentsPreservation.js

@@ -0,0 +1,30 @@
+//// [tests/cases/compiler/declarationEmitCommentsPreservation.ts] ////
+
+//// [declarationEmitCommentsPreservation.ts]
+// Comment
+export class DbObject {
+    // Comment
+    id: string = ""; // Comment
+    // Comment
+    method() { }
+}
+
+//// [declarationEmitCommentsPreservation.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.DbObject = void 0;
+// Comment
+class DbObject {
+    // Comment
+    id = ""; // Comment
+    // Comment
+    method() { }
+}
+exports.DbObject = DbObject;
+
+
+//// [declarationEmitCommentsPreservation.d.ts]
+export declare class DbObject {
+    id: string;
+    method(): void;
+}

testdata/baselines/reference/compiler/declarationEmitCommentsPreservation.symbols

@@ -0,0 +1,15 @@
+//// [tests/cases/compiler/declarationEmitCommentsPreservation.ts] ////
+
+=== declarationEmitCommentsPreservation.ts ===
+// Comment
+export class DbObject {
+>DbObject : Symbol(DbObject, Decl(declarationEmitCommentsPreservation.ts, 0, 0))
+
+    // Comment
+    id: string = ""; // Comment
+>id : Symbol(DbObject.id, Decl(declarationEmitCommentsPreservation.ts, 1, 23))
+
+    // Comment
+    method() { }
+>method : Symbol(DbObject.method, Decl(declarationEmitCommentsPreservation.ts, 3, 20))
+}

testdata/baselines/reference/compiler/declarationEmitCommentsPreservation.types

@@ -0,0 +1,16 @@
+//// [tests/cases/compiler/declarationEmitCommentsPreservation.ts] ////
+
+=== declarationEmitCommentsPreservation.ts ===
+// Comment
+export class DbObject {
+>DbObject : DbObject
+
+    // Comment
+    id: string = ""; // Comment
+>id : string
+>"" : ""
+
+    // Comment
+    method() { }
+>method : () => void
+}

testdata/baselines/reference/compiler/declarationEmitCommentsWithJSDoc.js

@@ -0,0 +1,64 @@
+//// [tests/cases/compiler/declarationEmitCommentsWithJSDoc.ts] ////
+
+//// [declarationEmitCommentsWithJSDoc.ts]
+// Regular comment - should be removed
+/**
+ * JSDoc comment - should be preserved
+ */
+export class DbObject {
+    // Regular comment - should be removed
+    /**
+     * JSDoc property comment
+     */
+    id: string = ""; // Trailing comment - should be removed
+
+    // Regular comment - should be removed
+    /**
+     * JSDoc method comment
+     * @returns void
+     */
+    method() { }
+}
+
+//// [declarationEmitCommentsWithJSDoc.js]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+exports.DbObject = void 0;
+// Regular comment - should be removed
+/**
+ * JSDoc comment - should be preserved
+ */
+class DbObject {
+    // Regular comment - should be removed
+    /**
+     * JSDoc property comment
+     */
+    id = ""; // Trailing comment - should be removed
+    // Regular comment - should be removed
+    /**
+     * JSDoc method comment
+     * @returns void
+     */
+    method() { }
+}
+exports.DbObject = DbObject;
+
+
+//// [declarationEmitCommentsWithJSDoc.d.ts]
+// Regular comment - should be removed
+/**
+ * JSDoc comment - should be preserved
+ */
+export declare class DbObject {
+    // Regular comment - should be removed
+    /**
+     * JSDoc property comment
+     */
+    id: string; // Trailing comment - should be removed
+    // Regular comment - should be removed
+    /**
+     * JSDoc method comment
+     * @returns void
+     */
+    method(): void;
+}

testdata/baselines/reference/compiler/declarationEmitCommentsWithJSDoc.symbols

@@ -0,0 +1,25 @@
+//// [tests/cases/compiler/declarationEmitCommentsWithJSDoc.ts] ////
+
+=== declarationEmitCommentsWithJSDoc.ts ===
+// Regular comment - should be removed
+/**
+ * JSDoc comment - should be preserved
+ */
+export class DbObject {
+>DbObject : Symbol(DbObject, Decl(declarationEmitCommentsWithJSDoc.ts, 0, 0))
+
+    // Regular comment - should be removed
+    /**
+     * JSDoc property comment
+     */
+    id: string = ""; // Trailing comment - should be removed
+>id : Symbol(DbObject.id, Decl(declarationEmitCommentsWithJSDoc.ts, 4, 23))
+
+    // Regular comment - should be removed
+    /**
+     * JSDoc method comment
+     * @returns void
+     */
+    method() { }
+>method : Symbol(DbObject.method, Decl(declarationEmitCommentsWithJSDoc.ts, 9, 20))
+}

testdata/baselines/reference/compiler/declarationEmitCommentsWithJSDoc.types

@@ -0,0 +1,26 @@
+//// [tests/cases/compiler/declarationEmitCommentsWithJSDoc.ts] ////
+
+=== declarationEmitCommentsWithJSDoc.ts ===
+// Regular comment - should be removed
+/**
+ * JSDoc comment - should be preserved
+ */
+export class DbObject {
+>DbObject : DbObject
+
+    // Regular comment - should be removed
+    /**
+     * JSDoc property comment
+     */
+    id: string = ""; // Trailing comment - should be removed
+>id : string
+>"" : ""
+
+    // Regular comment - should be removed
+    /**
+     * JSDoc method comment
+     * @returns void
+     */
+    method() { }
+>method : () => void
+}

testdata/baselines/reference/compiler/parameterPropertyWithDefaultValueExtended.js

@@ -65,27 +65,22 @@ export class PublicWithDefault {
 
 
 //// [parameterPropertyWithDefaultValueExtended.d.ts]
-// Test with default value - should not have undefined
 export declare class WithDefault {
     readonly timestamp: Date;
     constructor(timestamp?: Date);
 }
-// Test without default value but optional - should have undefined
 export declare class WithoutDefault {
     readonly timestamp?: Date | undefined;
     constructor(timestamp?: Date | undefined);
 }
-// Test with explicit undefined type - should keep it
 export declare class ExplicitUndefined {
     readonly timestamp: Date | undefined;
     constructor(timestamp?: Date | undefined);
 }
-// Test private parameter property with default value
 export declare class PrivateWithDefault {
     private timestamp;
     constructor(timestamp?: Date);
 }
-// Test public parameter property with default value
 export declare class PublicWithDefault {
     timestamp: Date;
     constructor(timestamp?: Date);

testdata/baselines/reference/conformance/jsdocVariadicInOverload.js

@@ -96,7 +96,6 @@ p.use(x, y, z);
 
 
 //// [typeTagForMultipleVariableDeclarations.d.ts]
-// based on code from unifiedjs/unified
 declare class Node {
 }
 /**

testdata/baselines/reference/submodule/compiler/anonClassDeclarationEmitIsAnon.js

@@ -90,7 +90,6 @@ declare const _default: {
     };
 };
 export default _default;
-// Simple class
 export declare class User {
     name: string;
 }
@@ -99,7 +98,6 @@ declare const TimestampedUser_base: {
         timestamp: number;
     };
 } & typeof User;
-// User that is Timestamped
 export declare class TimestampedUser extends TimestampedUser_base {
     constructor();
 }

testdata/baselines/reference/submodule/compiler/anonClassDeclarationEmitIsAnon.js.diff

@@ -26,20 +26,4 @@
 +    name = '';
  }
  exports.User = User;
- // User that is Timestamped
-@@= skipped -47, +42 lines =@@
-     };
- };
- export default _default;
-+// Simple class
- export declare class User {
-     name: string;
- }
-@@= skipped -8, +9 lines =@@
-         timestamp: number;
-     };
- } & typeof User;
-+// User that is Timestamped
- export declare class TimestampedUser extends TimestampedUser_base {
-     constructor();
- }
+ // User that is Timestamped