Bump version to 3.9.6 and LKG

Author: TypeScript Bot

lib/tsc.js

@@ -67,7 +67,7 @@ var __makeTemplateObject = (this && this.__makeTemplateObject) || function (cook
 var ts;
 (function (ts) {
     ts.versionMajorMinor = "3.9";
-    ts.version = "3.9.5";
+    ts.version = "3.9.6";
     function tryGetNativeMap() {
         return typeof Map !== "undefined" && "entries" in Map.prototype ? Map : undefined;
     }
@@ -5022,6 +5022,7 @@ var ts;
         Cannot_find_a_tsconfig_json_file_at_the_current_directory_Colon_0: diag(5081, ts.DiagnosticCategory.Error, "Cannot_find_a_tsconfig_json_file_at_the_current_directory_Colon_0_5081", "Cannot find a tsconfig.json file at the current directory: {0}."),
         _0_could_be_instantiated_with_an_arbitrary_type_which_could_be_unrelated_to_1: diag(5082, ts.DiagnosticCategory.Error, "_0_could_be_instantiated_with_an_arbitrary_type_which_could_be_unrelated_to_1_5082", "'{0}' could be instantiated with an arbitrary type which could be unrelated to '{1}'."),
         Cannot_read_file_0: diag(5083, ts.DiagnosticCategory.Error, "Cannot_read_file_0_5083", "Cannot read file '{0}'."),
+        The_inferred_type_of_0_references_a_type_with_a_cyclic_structure_which_cannot_be_trivially_serialized_A_type_annotation_is_necessary: diag(5088, ts.DiagnosticCategory.Error, "The_inferred_type_of_0_references_a_type_with_a_cyclic_structure_which_cannot_be_trivially_serialize_5088", "The inferred type of '{0}' references a type with a cyclic structure which cannot be trivially serialized. A type annotation is necessary."),
         Generates_a_sourcemap_for_each_corresponding_d_ts_file: diag(6000, ts.DiagnosticCategory.Message, "Generates_a_sourcemap_for_each_corresponding_d_ts_file_6000", "Generates a sourcemap for each corresponding '.d.ts' file."),
         Concatenate_and_emit_output_to_single_file: diag(6001, ts.DiagnosticCategory.Message, "Concatenate_and_emit_output_to_single_file_6001", "Concatenate and emit output to single file."),
         Generates_corresponding_d_ts_file: diag(6002, ts.DiagnosticCategory.Message, "Generates_corresponding_d_ts_file_6002", "Generates corresponding '.d.ts' file."),
@@ -12287,7 +12288,7 @@ var ts;
         if (!(name.kind === 154 || name.kind === 195)) {
             return false;
         }
-        var expr = ts.isElementAccessExpression(name) ? name.argumentExpression : name.expression;
+        var expr = ts.isElementAccessExpression(name) ? skipParentheses(name.argumentExpression) : name.expression;
         return !isStringOrNumericLiteralLike(expr) &&
             !isSignedNumericLiteral(expr) &&
             !isWellKnownSymbolSyntactically(expr);
@@ -31818,15 +31819,29 @@ var ts;
                     context.inferTypeParameters = type.root.inferTypeParameters;
                     var extendsTypeNode = typeToTypeNodeHelper(type.extendsType, context);
                     context.inferTypeParameters = saveInferTypeParameters;
-                    var trueTypeNode = typeToTypeNodeHelper(getTrueTypeFromConditionalType(type), context);
-                    var falseTypeNode = typeToTypeNodeHelper(getFalseTypeFromConditionalType(type), context);
+                    var trueTypeNode = typeToTypeNodeOrCircularityElision(getTrueTypeFromConditionalType(type));
+                    var falseTypeNode = typeToTypeNodeOrCircularityElision(getFalseTypeFromConditionalType(type));
                     context.approximateLength += 15;
                     return ts.createConditionalTypeNode(checkTypeNode, extendsTypeNode, trueTypeNode, falseTypeNode);
                 }
                 if (type.flags & 33554432) {
                     return typeToTypeNodeHelper(type.baseType, context);
                 }
                 return ts.Debug.fail("Should be unreachable.");
+                function typeToTypeNodeOrCircularityElision(type) {
+                    var _a, _b;
+                    if (type.flags & 1048576) {
+                        if (context.visitedTypes && context.visitedTypes.has("" + getTypeId(type))) {
+                            if (!(context.flags & 131072)) {
+                                context.encounteredError = true;
+                                (_b = (_a = context.tracker) === null || _a === void 0 ? void 0 : _a.reportCyclicStructureError) === null || _b === void 0 ? void 0 : _b.call(_a);
+                            }
+                            return createElidedInformationPlaceholder(context);
+                        }
+                        return visitAndTransformType(type, function (type) { return typeToTypeNodeHelper(type, context); });
+                    }
+                    return typeToTypeNodeHelper(type, context);
+                }
                 function createMappedTypeNodeFromType(type) {
                     ts.Debug.assert(!!(type.flags & 524288));
                     var readonlyToken = type.declaration.readonlyToken ? ts.createToken(type.declaration.readonlyToken.kind) : undefined;
@@ -38485,10 +38500,12 @@ var ts;
             }
             return links.resolvedType;
         }
-        function createIndexedAccessType(objectType, indexType) {
+        function createIndexedAccessType(objectType, indexType, aliasSymbol, aliasTypeArguments) {
             var type = createType(8388608);
             type.objectType = objectType;
             type.indexType = indexType;
+            type.aliasSymbol = aliasSymbol;
+            type.aliasTypeArguments = aliasTypeArguments;
             return type;
         }
         function isJSLiteralType(type) {
@@ -38762,10 +38779,10 @@ var ts;
             var templateMapper = combineTypeMappers(objectType.mapper, mapper);
             return instantiateType(getTemplateTypeFromMappedType(objectType), templateMapper);
         }
-        function getIndexedAccessType(objectType, indexType, accessNode) {
-            return getIndexedAccessTypeOrUndefined(objectType, indexType, accessNode, 0) || (accessNode ? errorType : unknownType);
+        function getIndexedAccessType(objectType, indexType, accessNode, aliasSymbol, aliasTypeArguments) {
+            return getIndexedAccessTypeOrUndefined(objectType, indexType, accessNode, 0, aliasSymbol, aliasTypeArguments) || (accessNode ? errorType : unknownType);
         }
-        function getIndexedAccessTypeOrUndefined(objectType, indexType, accessNode, accessFlags) {
+        function getIndexedAccessTypeOrUndefined(objectType, indexType, accessNode, accessFlags, aliasSymbol, aliasTypeArguments) {
             if (accessFlags === void 0) { accessFlags = 0; }
             if (objectType === wildcardType || indexType === wildcardType) {
                 return wildcardType;
@@ -38780,7 +38797,7 @@ var ts;
                 var id = objectType.id + "," + indexType.id;
                 var type = indexedAccessTypes.get(id);
                 if (!type) {
-                    indexedAccessTypes.set(id, type = createIndexedAccessType(objectType, indexType));
+                    indexedAccessTypes.set(id, type = createIndexedAccessType(objectType, indexType, aliasSymbol, aliasTypeArguments));
                 }
                 return type;
             }
@@ -38804,7 +38821,7 @@ var ts;
                 if (wasMissingProp) {
                     return undefined;
                 }
-                return accessFlags & 2 ? getIntersectionType(propTypes) : getUnionType(propTypes);
+                return accessFlags & 2 ? getIntersectionType(propTypes, aliasSymbol, aliasTypeArguments) : getUnionType(propTypes, 1, aliasSymbol, aliasTypeArguments);
             }
             return getPropertyTypeForIndexType(objectType, apparentObjectType, indexType, indexType, false, accessNode, accessFlags | 4);
         }
@@ -38813,7 +38830,8 @@ var ts;
             if (!links.resolvedType) {
                 var objectType = getTypeFromTypeNode(node.objectType);
                 var indexType = getTypeFromTypeNode(node.indexType);
-                var resolved = getIndexedAccessType(objectType, indexType, node);
+                var potentialAlias = getAliasSymbolForTypeNode(node);
+                var resolved = getIndexedAccessType(objectType, indexType, node, potentialAlias, getTypeArgumentsForAliasSymbol(potentialAlias));
                 links.resolvedType = resolved.flags & 8388608 &&
                     resolved.objectType === objectType &&
                     resolved.indexType === indexType ?
@@ -39762,7 +39780,7 @@ var ts;
                 return getIndexType(instantiateType(type.type, mapper));
             }
             if (flags & 8388608) {
-                return getIndexedAccessType(instantiateType(type.objectType, mapper), instantiateType(type.indexType, mapper));
+                return getIndexedAccessType(instantiateType(type.objectType, mapper), instantiateType(type.indexType, mapper), undefined, type.aliasSymbol, instantiateTypes(type.aliasTypeArguments, mapper));
             }
             if (flags & 16777216) {
                 return getConditionalTypeInstantiation(type, combineTypeMappers(type.mapper, mapper));
@@ -46242,6 +46260,9 @@ var ts;
                     return ts.Debug.assertNever(kind);
             }
         }
+        function isCircularMappedProperty(symbol) {
+            return !!(ts.getCheckFlags(symbol) & 262144 && !symbol.type && findResolutionCycleStartIndex(symbol, 0) >= 0);
+        }
         function getTypeOfPropertyOfContextualType(type, name) {
             return mapType(type, function (t) {
                 if (isGenericMappedType(t)) {
@@ -46255,7 +46276,7 @@ var ts;
                 else if (t.flags & 3670016) {
                     var prop = getPropertyOfType(t, name);
                     if (prop) {
-                        return getTypeOfSymbol(prop);
+                        return isCircularMappedProperty(prop) ? undefined : getTypeOfSymbol(prop);
                     }
                     if (isTupleType(t)) {
                         var restType = getRestTypeOfTupleType(t);
@@ -75534,6 +75555,7 @@ var ts;
             trackSymbol: trackSymbol,
             reportInaccessibleThisError: reportInaccessibleThisError,
             reportInaccessibleUniqueSymbolError: reportInaccessibleUniqueSymbolError,
+            reportCyclicStructureError: reportCyclicStructureError,
             reportPrivateInBaseOfClassExpression: reportPrivateInBaseOfClassExpression,
             reportLikelyUnsafeImportRequiredError: reportLikelyUnsafeImportRequiredError,
             moduleResolverHost: host,
@@ -75615,6 +75637,11 @@ var ts;
                 context.addDiagnostic(ts.createDiagnosticForNode(errorNameNode, ts.Diagnostics.The_inferred_type_of_0_references_an_inaccessible_1_type_A_type_annotation_is_necessary, ts.declarationNameToString(errorNameNode), "unique symbol"));
             }
         }
+        function reportCyclicStructureError() {
+            if (errorNameNode) {
+                context.addDiagnostic(ts.createDiagnosticForNode(errorNameNode, ts.Diagnostics.The_inferred_type_of_0_references_a_type_with_a_cyclic_structure_which_cannot_be_trivially_serialized_A_type_annotation_is_necessary, ts.declarationNameToString(errorNameNode)));
+            }
+        }
         function reportInaccessibleThisError() {
             if (errorNameNode) {
                 context.addDiagnostic(ts.createDiagnosticForNode(errorNameNode, ts.Diagnostics.The_inferred_type_of_0_references_an_inaccessible_1_type_A_type_annotation_is_necessary, ts.declarationNameToString(errorNameNode), "this"));