Declaration emit should retain (instead of elide) unresolved computed names

src/compiler/checker.ts

@@ -8459,7 +8459,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     );
                 }
                 if (isNamedDeclaration(node) && node.name.kind === SyntaxKind.ComputedPropertyName && !isLateBindableName(node.name)) {
-                    return undefined;
+                    if (!(context.flags & NodeBuilderFlags.AllowUnresolvedComputedNames && hasDynamicName(node) && isEntityNameExpression(node.name.expression) && checkComputedPropertyName(node.name).flags & TypeFlags.Any)) {
+                        return undefined;
+                    }
                 }
                 if (
                     (isFunctionLike(node) && !node.type)

src/compiler/transformers/declarations.ts

@@ -233,6 +233,7 @@ const declarationEmitNodeBuilderFlags = NodeBuilderFlags.MultilineObjectLiterals
     NodeBuilderFlags.UseTypeOfFunction |
     NodeBuilderFlags.UseStructuralFallback |
     NodeBuilderFlags.AllowEmptyTuple |
+    NodeBuilderFlags.AllowUnresolvedComputedNames |
     NodeBuilderFlags.GenerateNamesForShadowedTypeParams |
     NodeBuilderFlags.NoTruncation;
 
@@ -1006,7 +1007,12 @@ export function transformDeclarations(context: TransformationContext) {
                 ) {
                     context.addDiagnostic(createDiagnosticForNode(input, Diagnostics.Computed_properties_must_be_number_or_string_literals_variables_or_dotted_expressions_with_isolatedDeclarations));
                 }
-                return;
+                if (!isEntityNameExpression(input.name.expression)) {
+                    return;
+                }
+                // A.B.C that is not late bound - usually this means the expression did not resolve.
+                // Check the entity name, and copy the declaration, rather than elide it (there's
+                // probably a checker error in the input, but this is most likely the desired output).
             }
         }
 
@@ -1778,7 +1784,7 @@ export function transformDeclarations(context: TransformationContext) {
             getSymbolAccessibilityDiagnostic = createGetSymbolAccessibilityDiagnosticForNodeName(node);
         }
         errorNameNode = (node as NamedDeclaration).name;
-        Debug.assert(resolver.isLateBound(getParseTreeNode(node) as Declaration)); // Should only be called with dynamic names
+        Debug.assert(hasDynamicName(node as NamedDeclaration)); // Should only be called with dynamic names
         const decl = node as NamedDeclaration as LateBoundDeclaration;
         const entityName = decl.name.expression;
         checkEntityNameVisibility(entityName, enclosingDeclaration);

src/compiler/types.ts

@@ -5433,6 +5433,7 @@ export const enum NodeBuilderFlags {
     // Errors (cont.)
     AllowNodeModulesRelativePaths           = 1 << 26,
     /** @internal */ DoNotIncludeSymbolChain = 1 << 27,    // Skip looking up and printing an accessible symbol chain
+    /** @internal */ AllowUnresolvedComputedNames = 1 << 32,
 
     IgnoreErrors = AllowThisInObjectLiteral | AllowQualifiedNameInPlaceOfIdentifier | AllowAnonymousIdentifier | AllowEmptyUnionOrIntersection | AllowEmptyTuple | AllowEmptyIndexInfoType | AllowNodeModulesRelativePaths,
 

tests/baselines/reference/complicatedPrivacy.types

@@ -84,8 +84,8 @@ module m1 {
     }
 
     export function f4(arg1: 
->f4 : (arg1: {}) => void
->   : ^    ^^  ^^^^^^^^^
+>f4 : (arg1: { [number]: C1; }) => void
+>   : ^    ^^                 ^^^^^^^^^
 >arg1 : {}
 >     : ^^
     {

tests/baselines/reference/giant.js

@@ -14,6 +14,7 @@
 
     MAX DEPTH 3 LEVELS
 */
+const p = "propName";
 var V;
 function F() { };
 class C {
@@ -701,6 +702,7 @@ define(["require", "exports"], function (require, exports) {
 
         MAX DEPTH 3 LEVELS
     */
+    var p = "propName";
     var V;
     function F() { }
     ;
@@ -1114,6 +1116,7 @@ define(["require", "exports"], function (require, exports) {
 
 
 //// [giant.d.ts]
+declare const p = "propName";
 export declare var eV: any;
 export declare function eF(): void;
 export declare class eC {
@@ -1153,6 +1156,7 @@ export interface eI {
     new (...p3: any[]): any;
     new (p4: string, p5?: string): any;
     new (p6: string, ...p7: any[]): any;
+    [p]: any;
     [p1: string]: any;
     [p2: string, p3: number]: any;
     p: any;
@@ -1205,6 +1209,7 @@ export declare namespace eM {
         new (...p3: any[]): any;
         new (p4: string, p5?: string): any;
         new (p6: string, ...p7: any[]): any;
+        [p]: any;
         [p1: string]: any;
         [p2: string, p3: number]: any;
         p: any;
@@ -1320,6 +1325,7 @@ export declare namespace eaM {
         new (...p3: any[]): any;
         new (p4: string, p5?: string): any;
         new (p6: string, ...p7: any[]): any;
+        [p]: any;
         [p1: string]: any;
         [p2: string, p3: number]: any;
         p: any;
@@ -1379,6 +1385,7 @@ export declare namespace eaM {
         new (...p3: any[]): any;
         new (p4: string, p5?: string): any;
         new (p6: string, ...p7: any[]): any;
+        [p]: any;
         [p1: string]: any;
         [p2: string, p3: number]: any;
         p: any;
@@ -1406,3 +1413,4 @@ export declare namespace eaM {
         namespace eM { }
     }
 }
+export {};