diff --git a/src/compiler/binder.ts b/src/compiler/binder.ts
index 3cde8be7ea115..4a022f3f03ec8 100644
--- a/src/compiler/binder.ts
+++ b/src/compiler/binder.ts
@@ -659,7 +659,7 @@ namespace ts {
                 }
                 // We create a return control flow graph for IIFEs and constructors. For constructors
                 // we use the return control flow graph in strict property initialization checks.
-                currentReturnTarget = isIIFE || node.kind === SyntaxKind.Constructor ? createBranchLabel() : undefined;
+                currentReturnTarget = isIIFE || node.kind === SyntaxKind.Constructor || (isInJSFile && (node.kind === SyntaxKind.FunctionDeclaration || node.kind === SyntaxKind.FunctionExpression)) ? createBranchLabel() : undefined;
                 currentExceptionTarget = undefined;
                 currentBreakTarget = undefined;
                 currentContinueTarget = undefined;
@@ -680,8 +680,8 @@ namespace ts {
                 if (currentReturnTarget) {
                     addAntecedent(currentReturnTarget, currentFlow);
                     currentFlow = finishFlowLabel(currentReturnTarget);
-                    if (node.kind === SyntaxKind.Constructor) {
-                        (<ConstructorDeclaration>node).returnFlowNode = currentFlow;
+                    if (node.kind === SyntaxKind.Constructor || (isInJSFile && (node.kind === SyntaxKind.FunctionDeclaration || node.kind === SyntaxKind.FunctionExpression))) {
+                        (<FunctionLikeDeclaration>node).returnFlowNode = currentFlow;
                     }
                 }
                 if (!isIIFE) {
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 5cab127293b72..b6afc5582d269 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -7484,6 +7484,16 @@ namespace ts {
                 return addOptionality(type, isOptional);
             }
 
+            if (isPropertyDeclaration(declaration) && (noImplicitAny || isInJSFile(declaration))) {
+                // We have a property declaration with no type annotation or initializer, in noImplicitAny mode or a .js file.
+                // Use control flow analysis of this.xxx assignments the constructor to determine the type of the property.
+                const constructor = findConstructorDeclaration(declaration.parent);
+                const type = constructor ? getFlowTypeInConstructor(declaration.symbol, constructor) :
+                    getModifierFlags(declaration) & ModifierFlags.Ambient ? getTypeOfPropertyInBaseClass(declaration.symbol) :
+                    undefined;
+                return type && addOptionality(type, isOptional);
+            }
+
             if (isJsxAttribute(declaration)) {
                 // if JSX attribute doesn't have initializer, by default the attribute will have boolean value of true.
                 // I.e <Elem attr /> is sugar for <Elem attr={true} />
@@ -7500,6 +7510,59 @@ namespace ts {
             return undefined;
         }
 
+        function isConstructorDeclaredProperty(symbol: Symbol) {
+            // A propery is considered a constructor declared property when all declaration sites are this.xxx assignments,
+            // when no declaration sites have JSDoc type annotations, and when at least one declaration site is in the body of
+            // a class constructor.
+            if (symbol.valueDeclaration && isBinaryExpression(symbol.valueDeclaration)) {
+                const links = getSymbolLinks(symbol);
+                if (links.isConstructorDeclaredProperty === undefined) {
+                    links.isConstructorDeclaredProperty = !!getDeclaringConstructor(symbol) && every(symbol.declarations, declaration =>
+                        isBinaryExpression(declaration) &&
+                        getAssignmentDeclarationKind(declaration) === AssignmentDeclarationKind.ThisProperty &&
+                        (declaration.left.kind !== SyntaxKind.ElementAccessExpression || isStringOrNumericLiteralLike((<ElementAccessExpression>declaration.left).argumentExpression)) &&
+                        !getAnnotatedTypeForAssignmentDeclaration(/*declaredType*/ undefined, declaration, symbol, declaration));
+                }
+                return links.isConstructorDeclaredProperty;
+            }
+            return false;
+        }
+
+        function isAutoTypedProperty(symbol: Symbol) {
+            // A property is auto-typed when its declaration has no type annotation or initializer and we're in
+            // noImplicitAny mode or a .js file.
+            const declaration = symbol.valueDeclaration;
+            return declaration && isPropertyDeclaration(declaration) && !getEffectiveTypeAnnotationNode(declaration) &&
+                !declaration.initializer && (noImplicitAny || isInJSFile(declaration));
+        }
+
+        function getDeclaringConstructor(symbol: Symbol) {
+            for (const declaration of symbol.declarations) {
+                const container = getThisContainer(declaration, /*includeArrowFunctions*/ false);
+                if (container && (container.kind === SyntaxKind.Constructor || isJSConstructor(container))) {
+                    return <ConstructorDeclaration>container;
+                }
+            }
+        }
+
+        function getFlowTypeInConstructor(symbol: Symbol, constructor: ConstructorDeclaration) {
+            const reference = createPropertyAccess(createThis(), unescapeLeadingUnderscores(symbol.escapedName));
+            reference.expression.parent = reference;
+            reference.parent = constructor;
+            reference.flowNode = constructor.returnFlowNode;
+            const flowType = getFlowTypeOfProperty(reference, symbol);
+            if (noImplicitAny && (flowType === autoType || flowType === autoArrayType)) {
+                error(symbol.valueDeclaration, Diagnostics.Member_0_implicitly_has_an_1_type, symbolToString(symbol), typeToString(flowType));
+            }
+            // We don't infer a type if assignments are only null or undefined.
+            return everyType(flowType, isNullableType) ? undefined : convertAutoToAny(flowType);
+        }
+
+        function getFlowTypeOfProperty(reference: Node, prop: Symbol | undefined) {
+            const initialType = prop && (!isAutoTypedProperty(prop) || getModifierFlags(prop.valueDeclaration) & ModifierFlags.Ambient) && getTypeOfPropertyInBaseClass(prop) || undefinedType;
+            return getFlowTypeOfReference(reference, autoType, initialType);
+        }
+
         function getWidenedTypeForAssignmentDeclaration(symbol: Symbol, resolvedSymbol?: Symbol) {
             // function/class/{} initializers are themselves containers, so they won't merge in the same way as other initializers
             const container = getAssignedExpandoInitializer(symbol.valueDeclaration);
@@ -7511,52 +7574,60 @@ namespace ts {
                 const containerObjectType = getJSContainerObjectType(symbol.valueDeclaration, symbol, container);
                 return containerObjectType || getWidenedLiteralType(checkExpressionCached(container));
             }
+            let type;
             let definedInConstructor = false;
             let definedInMethod = false;
-            let jsdocType: Type | undefined;
-            let types: Type[] | undefined;
-            for (const declaration of symbol.declarations) {
-                const expression = (isBinaryExpression(declaration) || isCallExpression(declaration)) ? declaration :
-                    isAccessExpression(declaration) ? isBinaryExpression(declaration.parent) ? declaration.parent : declaration :
-                    undefined;
-                if (!expression) {
-                    continue; // Non-assignment declaration merged in (eg, an Identifier to mark the thing as a namespace) - skip over it and pull type info from elsewhere
-                }
+            // We use control flow analysis to determine the type of the property if the property qualifies as a constructor
+            // declared property and the resulting control flow type isn't just undefined or null.
+            if (isConstructorDeclaredProperty(symbol)) {
+                type = getFlowTypeInConstructor(symbol, getDeclaringConstructor(symbol)!);
+            }
+            if (!type) {
+                let jsdocType: Type | undefined;
+                let types: Type[] | undefined;
+                for (const declaration of symbol.declarations) {
+                    const expression = (isBinaryExpression(declaration) || isCallExpression(declaration)) ? declaration :
+                        isAccessExpression(declaration) ? isBinaryExpression(declaration.parent) ? declaration.parent : declaration :
+                        undefined;
+                    if (!expression) {
+                        continue; // Non-assignment declaration merged in (eg, an Identifier to mark the thing as a namespace) - skip over it and pull type info from elsewhere
+                    }
 
-                const kind = isAccessExpression(expression)
-                    ? getAssignmentDeclarationPropertyAccessKind(expression)
-                    : getAssignmentDeclarationKind(expression);
-                if (kind === AssignmentDeclarationKind.ThisProperty) {
-                    if (isDeclarationInConstructor(expression)) {
-                        definedInConstructor = true;
+                    const kind = isAccessExpression(expression)
+                        ? getAssignmentDeclarationPropertyAccessKind(expression)
+                        : getAssignmentDeclarationKind(expression);
+                    if (kind === AssignmentDeclarationKind.ThisProperty) {
+                        if (isDeclarationInConstructor(expression)) {
+                            definedInConstructor = true;
+                        }
+                        else {
+                            definedInMethod = true;
+                        }
                     }
-                    else {
-                        definedInMethod = true;
+                    if (!isCallExpression(expression)) {
+                        jsdocType = getAnnotatedTypeForAssignmentDeclaration(jsdocType, expression, symbol, declaration);
+                    }
+                    if (!jsdocType) {
+                        (types || (types = [])).push((isBinaryExpression(expression) || isCallExpression(expression)) ? getInitializerTypeFromAssignmentDeclaration(symbol, resolvedSymbol, expression, kind) : neverType);
                     }
                 }
-                if (!isCallExpression(expression)) {
-                    jsdocType = getAnnotatedTypeForAssignmentDeclaration(jsdocType, expression, symbol, declaration);
-                }
-                if (!jsdocType) {
-                    (types || (types = [])).push((isBinaryExpression(expression) || isCallExpression(expression)) ? getInitializerTypeFromAssignmentDeclaration(symbol, resolvedSymbol, expression, kind) : neverType);
-                }
-            }
-            let type = jsdocType;
-            if (!type) {
-                if (!length(types)) {
-                    return errorType; // No types from any declarations :(
-                }
-                let constructorTypes = definedInConstructor ? getConstructorDefinedThisAssignmentTypes(types!, symbol.declarations) : undefined;
-                // use only the constructor types unless they were only assigned null | undefined (including widening variants)
-                if (definedInMethod) {
-                    const propType = getTypeOfAssignmentDeclarationPropertyOfBaseType(symbol);
-                    if (propType) {
-                        (constructorTypes || (constructorTypes = [])).push(propType);
-                        definedInConstructor = true;
+                type = jsdocType;
+                if (!type) {
+                    if (!length(types)) {
+                        return errorType; // No types from any declarations :(
                     }
+                    let constructorTypes = definedInConstructor ? getConstructorDefinedThisAssignmentTypes(types!, symbol.declarations) : undefined;
+                    // use only the constructor types unless they were only assigned null | undefined (including widening variants)
+                    if (definedInMethod) {
+                        const propType = getTypeOfPropertyInBaseClass(symbol);
+                        if (propType) {
+                            (constructorTypes || (constructorTypes = [])).push(propType);
+                            definedInConstructor = true;
+                        }
+                    }
+                    const sourceTypes = some(constructorTypes, t => !!(t.flags & ~TypeFlags.Nullable)) ? constructorTypes : types; // TODO: GH#18217
+                    type = getUnionType(sourceTypes!, UnionReduction.Subtype);
                 }
-                const sourceTypes = some(constructorTypes, t => !!(t.flags & ~TypeFlags.Nullable)) ? constructorTypes : types; // TODO: GH#18217
-                type = getUnionType(sourceTypes!, UnionReduction.Subtype);
             }
             const widened = getWidenedType(addOptionality(type, definedInMethod && !definedInConstructor));
             if (filterType(widened, t => !!(t.flags & ~TypeFlags.Nullable)) === neverType) {
@@ -7701,21 +7772,6 @@ namespace ts {
             });
         }
 
-        /** check for definition in base class if any declaration is in a class */
-        function getTypeOfAssignmentDeclarationPropertyOfBaseType(property: Symbol) {
-            const parentDeclaration = forEach(property.declarations, d => {
-                const parent = getThisContainer(d, /*includeArrowFunctions*/ false).parent;
-                return isClassLike(parent) && parent;
-            });
-            if (parentDeclaration) {
-                const classType = getDeclaredTypeOfSymbol(getSymbolOfNode(parentDeclaration)) as InterfaceType;
-                const baseClassType = classType && getBaseTypes(classType)[0];
-                if (baseClassType) {
-                    return getTypeOfPropertyOfType(baseClassType, property.escapedName);
-                }
-            }
-        }
-
         // Return the type implied by a binding pattern element. This is the type of the initializer of the element if
         // one is present. Otherwise, if the element is itself a binding pattern, it is the type implied by the binding
         // pattern. Otherwise, it is the type any.
@@ -12704,6 +12760,9 @@ namespace ts {
                         if (accessFlags & AccessFlags.CacheSymbol) {
                             getNodeLinks(accessNode!).resolvedSymbol = prop;
                         }
+                        if (isThisPropertyAccessInConstructor(accessExpression, prop)) {
+                            return autoType;
+                        }
                     }
                     const propType = getTypeOfSymbol(prop);
                     return accessExpression && getAssignmentTargetKind(accessExpression) !== AssignmentKind.Definite ?
@@ -17284,7 +17343,14 @@ namespace ts {
 
         // Return the declaring class type of a property or undefined if property not declared in class
         function getDeclaringClass(prop: Symbol) {
-            return prop.parent && prop.parent.flags & SymbolFlags.Class ? getDeclaredTypeOfSymbol(getParentOfSymbol(prop)!) : undefined;
+            return prop.parent && prop.parent.flags & SymbolFlags.Class ? <InterfaceType>getDeclaredTypeOfSymbol(getParentOfSymbol(prop)!) : undefined;
+        }
+
+        // Return the inherited type of the given property or undefined if property doesn't exist in a base class.
+        function getTypeOfPropertyInBaseClass(property: Symbol) {
+            const classType = getDeclaringClass(property);
+            const baseClassType = classType && getBaseTypes(classType)[0];
+            return baseClassType && getTypeOfPropertyOfType(baseClassType, property.escapedName);
         }
 
         // Return true if some underlying source property is declared in a class that derives
@@ -20095,7 +20161,7 @@ namespace ts {
                         if (isEmptyArrayAssignment(node)) {
                             return getEvolvingArrayType(neverType);
                         }
-                        const assignedType = getBaseTypeOfLiteralType(getInitialOrAssignedType(flow));
+                        const assignedType = getWidenedLiteralType(getInitialOrAssignedType(flow));
                         return isTypeAssignableTo(assignedType, declaredType) ? assignedType : anyArrayType;
                     }
                     if (declaredType.flags & TypeFlags.Union) {
@@ -24031,6 +24097,10 @@ namespace ts {
             return false;
         }
 
+        function isThisPropertyAccessInConstructor(node: ElementAccessExpression | PropertyAccessExpression | QualifiedName, prop: Symbol) {
+            return isThisProperty(node) && (isAutoTypedProperty(prop) || isConstructorDeclaredProperty(prop)) && getThisContainer(node, /*includeArrowFunctions*/ true) === getDeclaringConstructor(prop);
+        }
+
         function checkPropertyAccessExpressionOrQualifiedName(node: PropertyAccessExpression | QualifiedName, left: Expression | QualifiedName, leftType: Type, right: Identifier | PrivateIdentifier) {
             const parentSymbol = getNodeLinks(left).resolvedSymbol;
             const assignmentKind = getAssignmentTargetKind(node);
@@ -24105,7 +24175,7 @@ namespace ts {
                     error(right, Diagnostics.Cannot_assign_to_0_because_it_is_a_read_only_property, idText(right));
                     return errorType;
                 }
-                propType = getConstraintForLocation(getTypeOfSymbol(prop), node);
+                propType = isThisPropertyAccessInConstructor(node, prop) ? autoType : getConstraintForLocation(getTypeOfSymbol(prop), node);
             }
             return getFlowTypeOfAccessExpression(node, prop, propType, right);
         }
@@ -24120,6 +24190,9 @@ namespace ts {
                 prop && !(prop.flags & (SymbolFlags.Variable | SymbolFlags.Property | SymbolFlags.Accessor)) && !(prop.flags & SymbolFlags.Method && propType.flags & TypeFlags.Union)) {
                 return propType;
             }
+            if (propType === autoType) {
+                return getFlowTypeOfProperty(node, prop);
+            }
             // If strict null checks and strict property initialization checks are enabled, if we have
             // a this.xxx property access, if the property is an instance property without an initializer,
             // and if we are in a constructor of the same class as the property declaration, assume that
diff --git a/src/compiler/types.ts b/src/compiler/types.ts
index b0a0658130b7b..0b67aea7f99d7 100644
--- a/src/compiler/types.ts
+++ b/src/compiler/types.ts
@@ -1107,6 +1107,7 @@ namespace ts {
         exclamationToken?: ExclamationToken;
         body?: Block | Expression;
         /* @internal */ endFlowNode?: FlowNode;
+        /* @internal */ returnFlowNode?: FlowNode;
     }
 
     export type FunctionLikeDeclaration =
@@ -1152,7 +1153,6 @@ namespace ts {
         kind: SyntaxKind.Constructor;
         parent: ClassLikeDeclaration;
         body?: FunctionBody;
-        /* @internal */ returnFlowNode?: FlowNode;
     }
 
     /** For when we encounter a semicolon in a class declaration. ES6 allows these as class elements. */
@@ -4156,6 +4156,7 @@ namespace ts {
         deferralParent?: Type;              // Source union/intersection of a deferred type
         cjsExportMerged?: Symbol;           // Version of the symbol with all non export= exports merged with the export= target
         typeOnlyDeclaration?: TypeOnlyCompatibleAliasDeclaration | false; // First resolved alias declaration that makes the symbol only usable in type constructs
+        isConstructorDeclaredProperty?: boolean;  // Property declared through 'this.x = ...' assignment in constructor
     }
 
     /* @internal */
diff --git a/tests/baselines/reference/checkExportsObjectAssignPrototypeProperty.types b/tests/baselines/reference/checkExportsObjectAssignPrototypeProperty.types
index a3bb9cd12cefa..6634a1a45ed3d 100644
--- a/tests/baselines/reference/checkExportsObjectAssignPrototypeProperty.types
+++ b/tests/baselines/reference/checkExportsObjectAssignPrototypeProperty.types
@@ -105,9 +105,9 @@ function Person(name) {
 
     this.name = name;
 >this.name = name : string
->this.name : string
+>this.name : any
 >this : this
->name : string
+>name : any
 >name : string
 }
 Person.prototype.describe = function () {
diff --git a/tests/baselines/reference/checkIndexConstraintOfJavascriptClassExpression.types b/tests/baselines/reference/checkIndexConstraintOfJavascriptClassExpression.types
index 5d58047f6e40b..465e3faea627f 100644
--- a/tests/baselines/reference/checkIndexConstraintOfJavascriptClassExpression.types
+++ b/tests/baselines/reference/checkIndexConstraintOfJavascriptClassExpression.types
@@ -23,9 +23,9 @@ someFunction(function(BaseClass) {
 
             this.foo = "bar";
 >this.foo = "bar" : "bar"
->this.foo : string
+>this.foo : any
 >this : this
->foo : string
+>foo : any
 >"bar" : "bar"
         }
         _render(error) {
diff --git a/tests/baselines/reference/checkJsFiles_noErrorLocation.types b/tests/baselines/reference/checkJsFiles_noErrorLocation.types
index d714782fed1c5..b0dceb2d33cad 100644
--- a/tests/baselines/reference/checkJsFiles_noErrorLocation.types
+++ b/tests/baselines/reference/checkJsFiles_noErrorLocation.types
@@ -25,9 +25,9 @@ class B extends A {
 
     this.foo = () => 3;
 >this.foo = () => 3 : () => number
->this.foo : () => number
+>this.foo : any
 >this : this
->foo : () => number
+>foo : any
 >() => 3 : () => number
 >3 : 3
   }
diff --git a/tests/baselines/reference/checkSuperCallBeforeThisAccessing9.types b/tests/baselines/reference/checkSuperCallBeforeThisAccessing9.types
index 577256400b2d7..c39389422f0bb 100644
--- a/tests/baselines/reference/checkSuperCallBeforeThisAccessing9.types
+++ b/tests/baselines/reference/checkSuperCallBeforeThisAccessing9.types
@@ -12,9 +12,9 @@ class Derived {
 
         this.x = 10;
 >this.x = 10 : 10
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >10 : 10
 
         var that = this;
diff --git a/tests/baselines/reference/classCanExtendConstructorFunction.types b/tests/baselines/reference/classCanExtendConstructorFunction.types
index c7a6770563aaa..f667ce4b15097 100644
--- a/tests/baselines/reference/classCanExtendConstructorFunction.types
+++ b/tests/baselines/reference/classCanExtendConstructorFunction.types
@@ -9,9 +9,9 @@ function Wagon(numberOxen) {
 
     this.numberOxen = numberOxen
 >this.numberOxen = numberOxen : number
->this.numberOxen : number
+>this.numberOxen : any
 >this : this
->numberOxen : number
+>numberOxen : any
 >numberOxen : number
 }
 /** @param {Wagon[]=} wagons */
@@ -91,9 +91,9 @@ class Sql extends Wagon {
 
         this.foonly = 12
 >this.foonly = 12 : 12
->this.foonly : number
+>this.foonly : any
 >this : this
->foonly : number
+>foonly : any
 >12 : 12
     }
     /**
diff --git a/tests/baselines/reference/classExtendingAny.types b/tests/baselines/reference/classExtendingAny.types
index fb585ed1de0d1..0916674963d44 100644
--- a/tests/baselines/reference/classExtendingAny.types
+++ b/tests/baselines/reference/classExtendingAny.types
@@ -67,9 +67,9 @@ class B extends Err {
 
         this.wat = 12
 >this.wat = 12 : 12
->this.wat : number
+>this.wat : any
 >this : this
->wat : number
+>wat : any
 >12 : 12
     }
     f() {
diff --git a/tests/baselines/reference/constructorFunctions.types b/tests/baselines/reference/constructorFunctions.types
index ba2fedb66438e..84ad439394dfa 100644
--- a/tests/baselines/reference/constructorFunctions.types
+++ b/tests/baselines/reference/constructorFunctions.types
@@ -143,9 +143,9 @@ function C6() {
 
   this.functions = [x => x, x => x + 1, x => x - 1]
 >this.functions = [x => x, x => x + 1, x => x - 1] : ((x: any) => any)[]
->this.functions : ((x: any) => any)[]
+>this.functions : any
 >this : this
->functions : ((x: any) => any)[]
+>functions : any
 >[x => x, x => x + 1, x => x - 1] : ((x: any) => any)[]
 >x => x : (x: any) => any
 >x : any
diff --git a/tests/baselines/reference/constructorFunctionsStrict.types b/tests/baselines/reference/constructorFunctionsStrict.types
index daeffbdd7ffc1..a92024920b55d 100644
--- a/tests/baselines/reference/constructorFunctionsStrict.types
+++ b/tests/baselines/reference/constructorFunctionsStrict.types
@@ -85,10 +85,10 @@ var j = new A(2)
 
 k.x === j.x
 >k.x === j.x : boolean
->k.x : number
+>k.x : number | undefined
 >k : A
->x : number
->j.x : number
+>x : number | undefined
+>j.x : number | undefined
 >j : A
->x : number
+>x : number | undefined
 
diff --git a/tests/baselines/reference/exportNestedNamespaces.types b/tests/baselines/reference/exportNestedNamespaces.types
index 97ce99af19a02..4bc7568885e18 100644
--- a/tests/baselines/reference/exportNestedNamespaces.types
+++ b/tests/baselines/reference/exportNestedNamespaces.types
@@ -32,9 +32,9 @@ exports.Classic = class {
     constructor() {
         this.p = 1
 >this.p = 1 : 1
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/inferringClassMembersFromAssignments.types b/tests/baselines/reference/inferringClassMembersFromAssignments.types
index 3d168707fe62a..c962aa841d821 100644
--- a/tests/baselines/reference/inferringClassMembersFromAssignments.types
+++ b/tests/baselines/reference/inferringClassMembersFromAssignments.types
@@ -11,24 +11,24 @@ class C {
 
             this.inConstructor = 0;
 >this.inConstructor = 0 : 0
->this.inConstructor : string | number
+>this.inConstructor : any
 >this : this
->inConstructor : string | number
+>inConstructor : any
 >0 : 0
         }
         else {
             this.inConstructor = "string"
 >this.inConstructor = "string" : "string"
->this.inConstructor : string | number
+>this.inConstructor : any
 >this : this
->inConstructor : string | number
+>inConstructor : any
 >"string" : "string"
         }
         this.inMultiple = 0;
 >this.inMultiple = 0 : 0
->this.inMultiple : number
+>this.inMultiple : any
 >this : this
->inMultiple : number
+>inMultiple : any
 >0 : 0
     }
     method() {
diff --git a/tests/baselines/reference/inferringClassMembersFromAssignments3.types b/tests/baselines/reference/inferringClassMembersFromAssignments3.types
index 60d545b2832fe..66394eb9ed143 100644
--- a/tests/baselines/reference/inferringClassMembersFromAssignments3.types
+++ b/tests/baselines/reference/inferringClassMembersFromAssignments3.types
@@ -5,9 +5,9 @@ class Base {
     constructor() {
         this.p = 1
 >this.p = 1 : 1
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/inferringClassMembersFromAssignments5.types b/tests/baselines/reference/inferringClassMembersFromAssignments5.types
index fc95b82e5fdeb..6bc1f2482d857 100644
--- a/tests/baselines/reference/inferringClassMembersFromAssignments5.types
+++ b/tests/baselines/reference/inferringClassMembersFromAssignments5.types
@@ -25,9 +25,9 @@ class Derived extends Base {
         // should be OK, and p should have type number from this assignment
         this.p = 1
 >this.p = 1 : 1
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >1 : 1
     }
     test() {
diff --git a/tests/baselines/reference/jsDeclarationsClasses.types b/tests/baselines/reference/jsDeclarationsClasses.types
index bbcea688c2691..853bb6b89969f 100644
--- a/tests/baselines/reference/jsDeclarationsClasses.types
+++ b/tests/baselines/reference/jsDeclarationsClasses.types
@@ -209,16 +209,16 @@ export class K {
     constructor() {
         this.p1 = 12;
 >this.p1 = 12 : 12
->this.p1 : number
+>this.p1 : any
 >this : this
->p1 : number
+>p1 : any
 >12 : 12
 
         this.p2 = "ok";
 >this.p2 = "ok" : "ok"
->this.p2 : string
+>this.p2 : any
 >this : this
->p2 : string
+>p2 : any
 >"ok" : "ok"
     }
 
@@ -243,9 +243,9 @@ export class M extends null {
     constructor() {
         this.prop = 12;
 >this.prop = 12 : 12
->this.prop : number
+>this.prop : any
 >this : this
->prop : number
+>prop : any
 >12 : 12
     }
 }
@@ -270,9 +270,9 @@ export class N extends L {
 
         this.another = param;
 >this.another = param : T
->this.another : T
+>this.another : any
 >this : this
->another : T
+>another : any
 >param : T
     }
 }
@@ -298,9 +298,9 @@ export class O extends N {
 
         this.another2 = param;
 >this.another2 = param : U
->this.another2 : U
+>this.another2 : any
 >this : this
->another2 : U
+>another2 : any
 >param : U
     }
 }
diff --git a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpression.types b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpression.types
index b2c7f801eb747..301d4f4adc528 100644
--- a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpression.types
+++ b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpression.types
@@ -15,9 +15,9 @@ module.exports = class Thing {
 
         this.t = 12 + p;
 >this.t = 12 + p : number
->this.t : number
+>this.t : any
 >this : this
->t : number
+>t : any
 >12 + p : number
 >12 : 12
 >p : number
diff --git a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymous.types b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymous.types
index ce144f50ebc53..dc75cbed876fd 100644
--- a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymous.types
+++ b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymous.types
@@ -14,9 +14,9 @@ module.exports = class {
 
         this.t = 12 + p;
 >this.t = 12 + p : number
->this.t : number
+>this.t : any
 >this : this
->t : number
+>t : any
 >12 + p : number
 >12 : 12
 >p : number
diff --git a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymousWithSub.types b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymousWithSub.types
index ccf33572b9891..904bbe069441a 100644
--- a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymousWithSub.types
+++ b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionAnonymousWithSub.types
@@ -14,9 +14,9 @@ module.exports = class {
 
         this.t = 12 + p;
 >this.t = 12 + p : number
->this.t : number
+>this.t : any
 >this : this
->t : number
+>t : any
 >12 + p : number
 >12 : 12
 >p : number
@@ -34,9 +34,9 @@ module.exports.Sub = class {
     constructor() {
         this.instance = new module.exports(10);
 >this.instance = new module.exports(10) : import("tests/cases/conformance/jsdoc/declarations/index")
->this.instance : import("tests/cases/conformance/jsdoc/declarations/index")
+>this.instance : any
 >this : this
->instance : import("tests/cases/conformance/jsdoc/declarations/index")
+>instance : any
 >new module.exports(10) : import("tests/cases/conformance/jsdoc/declarations/index")
 >module.exports : typeof import("tests/cases/conformance/jsdoc/declarations/index")
 >module : { "\"tests/cases/conformance/jsdoc/declarations/index\"": typeof import("tests/cases/conformance/jsdoc/declarations/index"); }
diff --git a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionShadowing.types b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionShadowing.types
index b7c41fe7fbb6a..36fdb5bfdc4e3 100644
--- a/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionShadowing.types
+++ b/tests/baselines/reference/jsDeclarationsExportAssignedClassExpressionShadowing.types
@@ -25,9 +25,9 @@ module.exports = class Q {
     constructor() {
         this.x = new A();
 >this.x = new A() : A
->this.x : A
+>this.x : any
 >this : this
->x : A
+>x : any
 >new A() : A
 >A : typeof A
     }
diff --git a/tests/baselines/reference/jsDeclarationsExportAssignedConstructorFunction.types b/tests/baselines/reference/jsDeclarationsExportAssignedConstructorFunction.types
index bbdaa717fb273..d7f0ad5272155 100644
--- a/tests/baselines/reference/jsDeclarationsExportAssignedConstructorFunction.types
+++ b/tests/baselines/reference/jsDeclarationsExportAssignedConstructorFunction.types
@@ -11,9 +11,9 @@ module.exports.MyClass = function() {
 
     this.x = 1
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
 }
 module.exports.MyClass.prototype = {
diff --git a/tests/baselines/reference/jsDeclarationsExportAssignedVisibility.types b/tests/baselines/reference/jsDeclarationsExportAssignedVisibility.types
index e54216161b930..a76835e3105a6 100644
--- a/tests/baselines/reference/jsDeclarationsExportAssignedVisibility.types
+++ b/tests/baselines/reference/jsDeclarationsExportAssignedVisibility.types
@@ -11,9 +11,9 @@ class Container {
     constructor() {
         this.usage = new Obj();
 >this.usage = new Obj() : import("tests/cases/conformance/jsdoc/declarations/obj")
->this.usage : import("tests/cases/conformance/jsdoc/declarations/obj")
+>this.usage : any
 >this : this
->usage : import("tests/cases/conformance/jsdoc/declarations/obj")
+>usage : any
 >new Obj() : import("tests/cases/conformance/jsdoc/declarations/obj")
 >Obj : typeof import("tests/cases/conformance/jsdoc/declarations/obj")
     }
@@ -38,9 +38,9 @@ module.exports = class Obj {
     constructor() {
         this.x = 12;
 >this.x = 12 : 12
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >12 : 12
     }
 }
diff --git a/tests/baselines/reference/jsDeclarationsTypedefAndImportTypes.types b/tests/baselines/reference/jsDeclarationsTypedefAndImportTypes.types
index 6441a279a4342..d4242cb21a78d 100644
--- a/tests/baselines/reference/jsDeclarationsTypedefAndImportTypes.types
+++ b/tests/baselines/reference/jsDeclarationsTypedefAndImportTypes.types
@@ -38,9 +38,9 @@ class Wrap {
 
         this.connItem = c.item;
 >this.connItem = c.item : number
->this.connItem : number
+>this.connItem : any
 >this : this
->connItem : number
+>connItem : any
 >c.item : number
 >c : import("tests/cases/conformance/jsdoc/declarations/conn")
 >item : number
diff --git a/tests/baselines/reference/jsFileClassPropertyType.types b/tests/baselines/reference/jsFileClassPropertyType.types
index bf1605d5bc6ef..686560e360522 100644
--- a/tests/baselines/reference/jsFileClassPropertyType.types
+++ b/tests/baselines/reference/jsFileClassPropertyType.types
@@ -5,9 +5,9 @@ class C {
   constructor () {
       this.p = 0;
 >this.p = 0 : 0
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >0 : 0
   }
 }
diff --git a/tests/baselines/reference/jsFileClassPropertyType3.types b/tests/baselines/reference/jsFileClassPropertyType3.types
index eea855579aee1..aee74b9787efb 100644
--- a/tests/baselines/reference/jsFileClassPropertyType3.types
+++ b/tests/baselines/reference/jsFileClassPropertyType3.types
@@ -8,17 +8,17 @@ class C {
 
             this.p = null;
 >this.p = null : null
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >null : null
         }
         else {
             this.p = 0;
 >this.p = 0 : 0
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >0 : 0
         }
     }
diff --git a/tests/baselines/reference/jsFileClassSelfReferencedProperty.types b/tests/baselines/reference/jsFileClassSelfReferencedProperty.types
index 204eee67c9707..9700c12ddd0da 100644
--- a/tests/baselines/reference/jsFileClassSelfReferencedProperty.types
+++ b/tests/baselines/reference/jsFileClassSelfReferencedProperty.types
@@ -4,15 +4,15 @@ export class StackOverflowTest {
 
   constructor () {
     this.testStackOverflow = this.testStackOverflow.bind(this)
->this.testStackOverflow = this.testStackOverflow.bind(this) : any
+>this.testStackOverflow = this.testStackOverflow.bind(this) : error
 >this.testStackOverflow : any
 >this : this
 >testStackOverflow : any
->this.testStackOverflow.bind(this) : any
->this.testStackOverflow.bind : any
->this.testStackOverflow : any
+>this.testStackOverflow.bind(this) : error
+>this.testStackOverflow.bind : error
+>this.testStackOverflow : undefined
 >this : this
->testStackOverflow : any
+>testStackOverflow : undefined
 >bind : any
 >this : this
   }
diff --git a/tests/baselines/reference/jsObjectsMarkedAsOpenEnded.types b/tests/baselines/reference/jsObjectsMarkedAsOpenEnded.types
index 996165537bc9b..777f779e9c78c 100644
--- a/tests/baselines/reference/jsObjectsMarkedAsOpenEnded.types
+++ b/tests/baselines/reference/jsObjectsMarkedAsOpenEnded.types
@@ -20,9 +20,9 @@ class C {
     constructor() {
         this.member = {};
 >this.member = {} : {}
->this.member : {}
+>this.member : any
 >this : this
->member : {}
+>member : any
 >{} : {}
 
         this.member.a = 0;
diff --git a/tests/baselines/reference/jsdocAccessibilityTags.types b/tests/baselines/reference/jsdocAccessibilityTags.types
index 18a364c4da843..a16c3456f2e67 100644
--- a/tests/baselines/reference/jsdocAccessibilityTags.types
+++ b/tests/baselines/reference/jsdocAccessibilityTags.types
@@ -52,9 +52,9 @@ class C {
          */
         this.priv2 = 1;
 >this.priv2 = 1 : 1
->this.priv2 : number
+>this.priv2 : any
 >this : this
->priv2 : number
+>priv2 : any
 >1 : 1
 
         /**
@@ -64,9 +64,9 @@ class C {
          */
         this.prot2 = 2;
 >this.prot2 = 2 : 2
->this.prot2 : number
+>this.prot2 : any
 >this : this
->prot2 : number
+>prot2 : any
 >2 : 2
 
         /**
@@ -76,9 +76,9 @@ class C {
          */
         this.pub2 = 3;
 >this.pub2 = 3 : 3
->this.pub2 : number
+>this.pub2 : any
 >this : this
->pub2 : number
+>pub2 : any
 >3 : 3
     }
     h() { return this.priv2 }
diff --git a/tests/baselines/reference/jsdocAugmentsMissingType.types b/tests/baselines/reference/jsdocAugmentsMissingType.types
index de0ba42cdd26a..430fae254806f 100644
--- a/tests/baselines/reference/jsdocAugmentsMissingType.types
+++ b/tests/baselines/reference/jsdocAugmentsMissingType.types
@@ -2,9 +2,9 @@
 class A { constructor() { this.x = 0; } }
 >A : A
 >this.x = 0 : 0
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >0 : 0
 
 /** @augments */
diff --git a/tests/baselines/reference/jsdocAugments_noExtends.types b/tests/baselines/reference/jsdocAugments_noExtends.types
index fab9c7b7c84e8..31c79acc60a5a 100644
--- a/tests/baselines/reference/jsdocAugments_noExtends.types
+++ b/tests/baselines/reference/jsdocAugments_noExtends.types
@@ -2,9 +2,9 @@
 class A { constructor() { this.x = 0; } }
 >A : A
 >this.x = 0 : 0
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >0 : 0
 
 /** @augments A */
diff --git a/tests/baselines/reference/jsdocFunctionType.types b/tests/baselines/reference/jsdocFunctionType.types
index 6349dccb10a49..f43ce2e84e2e2 100644
--- a/tests/baselines/reference/jsdocFunctionType.types
+++ b/tests/baselines/reference/jsdocFunctionType.types
@@ -44,9 +44,9 @@ class C {
 
         this.length = n;
 >this.length = n : number
->this.length : number
+>this.length : any
 >this : this
->length : number
+>length : any
 >n : number
     }
 }
@@ -92,9 +92,9 @@ function D(n) {
 
   this.length = n;
 >this.length = n : number
->this.length : number
+>this.length : any
 >this : this
->length : number
+>length : any
 >n : number
 }
 
@@ -151,9 +151,9 @@ var E = function(n) {
 
   this.not_length_on_purpose = n;
 >this.not_length_on_purpose = n : number
->this.not_length_on_purpose : number
+>this.not_length_on_purpose : any
 >this : this
->not_length_on_purpose : number
+>not_length_on_purpose : any
 >n : number
 
 };
diff --git a/tests/baselines/reference/jsdocImplements_missingType.types b/tests/baselines/reference/jsdocImplements_missingType.types
index 7a63d6aa5f211..370d360db0a75 100644
--- a/tests/baselines/reference/jsdocImplements_missingType.types
+++ b/tests/baselines/reference/jsdocImplements_missingType.types
@@ -2,9 +2,9 @@
 class A { constructor() { this.x = 0; } }
 >A : A
 >this.x = 0 : 0
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >0 : 0
 
 /** @implements */
diff --git a/tests/baselines/reference/jsdocImplements_properties.types b/tests/baselines/reference/jsdocImplements_properties.types
index fb00977b860e2..79f7a3d5a0bc6 100644
--- a/tests/baselines/reference/jsdocImplements_properties.types
+++ b/tests/baselines/reference/jsdocImplements_properties.types
@@ -2,9 +2,9 @@
 class A { constructor() { this.x = 0; } }
 >A : A
 >this.x = 0 : 0
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >0 : 0
 
 /** @implements A*/
@@ -26,9 +26,9 @@ class B3 {
 
     constructor() { this.x = 10 }
 >this.x = 10 : 10
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >10 : 10
 }
 
diff --git a/tests/baselines/reference/jsdocImportType.types b/tests/baselines/reference/jsdocImportType.types
index fd3157c19dc1a..b1d7542475079 100644
--- a/tests/baselines/reference/jsdocImportType.types
+++ b/tests/baselines/reference/jsdocImportType.types
@@ -45,9 +45,9 @@ class Chunk {
     constructor() {
         this.chunk = 1;
 >this.chunk = 1 : 1
->this.chunk : number
+>this.chunk : any
 >this : this
->chunk : number
+>chunk : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/jsdocImportType2.types b/tests/baselines/reference/jsdocImportType2.types
index 635dfc1ff1e76..f4386faf5a695 100644
--- a/tests/baselines/reference/jsdocImportType2.types
+++ b/tests/baselines/reference/jsdocImportType2.types
@@ -50,9 +50,9 @@ module.exports = class Chunk {
     constructor() {
         this.chunk = 1;
 >this.chunk = 1 : 1
->this.chunk : number
+>this.chunk : any
 >this : this
->chunk : number
+>chunk : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/jsdocReadonly.types b/tests/baselines/reference/jsdocReadonly.types
index 8a0f0806a2497..806623749cd3d 100644
--- a/tests/baselines/reference/jsdocReadonly.types
+++ b/tests/baselines/reference/jsdocReadonly.types
@@ -35,9 +35,9 @@ class LOL {
         /** @readonly ok */
         this.ka = 2
 >this.ka = 2 : 2
->this.ka : number
+>this.ka : any
 >this : this
->ka : number
+>ka : any
 >2 : 2
     }
 }
diff --git a/tests/baselines/reference/jsdocTemplateClass.types b/tests/baselines/reference/jsdocTemplateClass.types
index 6e5695ca83787..0479abccf3ebd 100644
--- a/tests/baselines/reference/jsdocTemplateClass.types
+++ b/tests/baselines/reference/jsdocTemplateClass.types
@@ -14,9 +14,9 @@ class Foo {
 
         this.a = x
 >this.a = x : T
->this.a : T
+>this.a : any
 >this : this
->a : T
+>a : any
 >x : T
     }
     /**
diff --git a/tests/baselines/reference/jsdocTypeReferenceToImportOfClassExpression.types b/tests/baselines/reference/jsdocTypeReferenceToImportOfClassExpression.types
index 98f18bc8fb086..0645f6adfda1f 100644
--- a/tests/baselines/reference/jsdocTypeReferenceToImportOfClassExpression.types
+++ b/tests/baselines/reference/jsdocTypeReferenceToImportOfClassExpression.types
@@ -39,9 +39,9 @@ class MW {
 
     this.compiler = compiler;
 >this.compiler = compiler : import("tests/cases/conformance/jsdoc/MC")
->this.compiler : import("tests/cases/conformance/jsdoc/MC")
+>this.compiler : any
 >this : this
->compiler : import("tests/cases/conformance/jsdoc/MC")
+>compiler : any
 >compiler : import("tests/cases/conformance/jsdoc/MC")
   }
 }
diff --git a/tests/baselines/reference/jsdocTypeReferenceToImportOfFunctionExpression.types b/tests/baselines/reference/jsdocTypeReferenceToImportOfFunctionExpression.types
index 1747fecbf6c38..81422f0c76c9d 100644
--- a/tests/baselines/reference/jsdocTypeReferenceToImportOfFunctionExpression.types
+++ b/tests/baselines/reference/jsdocTypeReferenceToImportOfFunctionExpression.types
@@ -42,9 +42,9 @@ class MW {
 
     this.compiler = compiler;
 >this.compiler = compiler : typeof MC
->this.compiler : typeof MC
+>this.compiler : any
 >this : this
->compiler : typeof MC
+>compiler : any
 >compiler : typeof MC
   }
 }
diff --git a/tests/baselines/reference/jsdocTypeTagCast.types b/tests/baselines/reference/jsdocTypeTagCast.types
index dc40ea0d950d2..f7e9136ca34f5 100644
--- a/tests/baselines/reference/jsdocTypeTagCast.types
+++ b/tests/baselines/reference/jsdocTypeTagCast.types
@@ -43,9 +43,9 @@ class SomeBase {
     constructor() {
         this.p = 42;
 >this.p = 42 : 42
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >42 : 42
     }
 }
@@ -60,9 +60,9 @@ class SomeDerived extends SomeBase {
 
         this.x = 42;
 >this.x = 42 : 42
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >42 : 42
     }
 }
@@ -72,9 +72,9 @@ class SomeOther {
     constructor() {
         this.q = 42;
 >this.q = 42 : 42
->this.q : number
+>this.q : any
 >this : this
->q : number
+>q : any
 >42 : 42
     }
 }
diff --git a/tests/baselines/reference/moduleExportAssignment6.types b/tests/baselines/reference/moduleExportAssignment6.types
index e1fd4a4dd1253..ee4122873c0c8 100644
--- a/tests/baselines/reference/moduleExportAssignment6.types
+++ b/tests/baselines/reference/moduleExportAssignment6.types
@@ -8,16 +8,16 @@ class C {
 
         this.x = x
 >this.x = x : number
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >x : number
 
         this.exports = [x]
 >this.exports = [x] : number[]
->this.exports : number[]
+>this.exports : any
 >this : this
->exports : number[]
+>exports : any
 >[x] : number[]
 >x : number
     }
diff --git a/tests/baselines/reference/moduleExportNestedNamespaces.types b/tests/baselines/reference/moduleExportNestedNamespaces.types
index 249739a3beb8a..a1fc39b723c68 100644
--- a/tests/baselines/reference/moduleExportNestedNamespaces.types
+++ b/tests/baselines/reference/moduleExportNestedNamespaces.types
@@ -39,9 +39,9 @@ module.exports.Classic = class {
     constructor() {
         this.p = 1
 >this.p = 1 : 1
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/propertiesOfGenericConstructorFunctions.types b/tests/baselines/reference/propertiesOfGenericConstructorFunctions.types
index 71ef32425aba7..42bf2ea2e9459 100644
--- a/tests/baselines/reference/propertiesOfGenericConstructorFunctions.types
+++ b/tests/baselines/reference/propertiesOfGenericConstructorFunctions.types
@@ -94,16 +94,16 @@ function Cp(t) {
 
     this.x = 1
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
 
     this.y = t
 >this.y = t : T
->this.y : T
+>this.y : any
 >this : this
->y : T
+>y : any
 >t : T
 }
 Cp.prototype = {
diff --git a/tests/baselines/reference/returnTagTypeGuard.types b/tests/baselines/reference/returnTagTypeGuard.types
index a8211118ea945..7056faa133697 100644
--- a/tests/baselines/reference/returnTagTypeGuard.types
+++ b/tests/baselines/reference/returnTagTypeGuard.types
@@ -5,9 +5,9 @@ class Entry {
     constructor() {
         this.c = 1
 >this.c = 1 : 1
->this.c : number
+>this.c : any
 >this : this
->c : number
+>c : any
 >1 : 1
     }
     /**
@@ -28,9 +28,9 @@ class Group {
     constructor() {
         this.d = 'no'
 >this.d = 'no' : "no"
->this.d : string
+>this.d : any
 >this : this
->d : string
+>d : any
 >'no' : "no"
     }
     /**
diff --git a/tests/baselines/reference/thisPropertyAssignment.types b/tests/baselines/reference/thisPropertyAssignment.types
index c919f47db1eec..ad2459773523e 100644
--- a/tests/baselines/reference/thisPropertyAssignment.types
+++ b/tests/baselines/reference/thisPropertyAssignment.types
@@ -44,9 +44,9 @@ function F() {
 
   this.a = {};
 >this.a = {} : {}
->this.a : {}
+>this.a : any
 >this : this
->a : {}
+>a : any
 >{} : {}
 
   this.a.b = {};
@@ -60,7 +60,7 @@ function F() {
 
   this["b"] = {};
 >this["b"] = {} : {}
->this["b"] : {}
+>this["b"] : any
 >this : this
 >"b" : "b"
 >{} : {}
diff --git a/tests/baselines/reference/thisPropertyAssignmentCircular.symbols b/tests/baselines/reference/thisPropertyAssignmentCircular.symbols
index 69bde885d529a..efaf0a1235e09 100644
--- a/tests/baselines/reference/thisPropertyAssignmentCircular.symbols
+++ b/tests/baselines/reference/thisPropertyAssignmentCircular.symbols
@@ -44,8 +44,10 @@ function C() {
 >this.x : Symbol(C.x, Decl(thisPropertyAssignmentCircular.js, 13, 14), Decl(thisPropertyAssignmentCircular.js, 14, 15))
 >this : Symbol(C, Decl(thisPropertyAssignmentCircular.js, 10, 1))
 >x : Symbol(C.x, Decl(thisPropertyAssignmentCircular.js, 13, 14), Decl(thisPropertyAssignmentCircular.js, 14, 15))
+>this.x.toString : Symbol(Function.toString, Decl(lib.es5.d.ts, --, --))
 >this.x : Symbol(C.x, Decl(thisPropertyAssignmentCircular.js, 13, 14), Decl(thisPropertyAssignmentCircular.js, 14, 15))
 >this : Symbol(C, Decl(thisPropertyAssignmentCircular.js, 10, 1))
 >x : Symbol(C.x, Decl(thisPropertyAssignmentCircular.js, 13, 14), Decl(thisPropertyAssignmentCircular.js, 14, 15))
+>toString : Symbol(Function.toString, Decl(lib.es5.d.ts, --, --))
 }
 
diff --git a/tests/baselines/reference/thisPropertyAssignmentCircular.types b/tests/baselines/reference/thisPropertyAssignmentCircular.types
index 1b5f8ae3dea32..bdeba6dfebace 100644
--- a/tests/baselines/reference/thisPropertyAssignmentCircular.types
+++ b/tests/baselines/reference/thisPropertyAssignmentCircular.types
@@ -5,9 +5,9 @@ export class Foo {
     constructor() {
         this.foo = "Hello";
 >this.foo = "Hello" : "Hello"
->this.foo : string
+>this.foo : any
 >this : this
->foo : string
+>foo : any
 >"Hello" : "Hello"
     }
     slicey() {
@@ -52,11 +52,11 @@ function C() {
 >this : this
 >x : any
 >function() { this.x.toString(); } : () => void
->this.x.toString() : any
->this.x.toString : any
->this.x : any
+>this.x.toString() : string
+>this.x.toString : () => string
+>this.x : () => void
 >this : this
->x : any
->toString : any
+>x : () => void
+>toString : () => string
 }
 
diff --git a/tests/baselines/reference/thisPropertyOverridesAccessors.types b/tests/baselines/reference/thisPropertyOverridesAccessors.types
index c242351dbd2b2..84da977ac1250 100644
--- a/tests/baselines/reference/thisPropertyOverridesAccessors.types
+++ b/tests/baselines/reference/thisPropertyOverridesAccessors.types
@@ -23,9 +23,9 @@ class Bar extends Foo {
 
         this.p = 2
 >this.p = 2 : 2
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >2 : 2
     }
 }
diff --git a/tests/baselines/reference/thisTypeOfConstructorFunctions.types b/tests/baselines/reference/thisTypeOfConstructorFunctions.types
index 126c0c9321a2e..2bd9ada0ac3d2 100644
--- a/tests/baselines/reference/thisTypeOfConstructorFunctions.types
+++ b/tests/baselines/reference/thisTypeOfConstructorFunctions.types
@@ -18,17 +18,17 @@ function Cp(t) {
 
     this.y = t
 >this.y = t : T
->this.y : T
+>this.y : any
 >this : this
->y : T
+>y : any
 >t : T
 
     /** @return {this} */
     this.m3 = () => this
 >this.m3 = () => this : () => this
->this.m3 : () => this
+>this.m3 : any
 >this : this
->m3 : () => this
+>m3 : any
 >() => this : () => this
 >this : this
 }
@@ -67,9 +67,9 @@ function Cpp(t) {
 
     this.y = t
 >this.y = t : T
->this.y : T
+>this.y : any
 >this : this
->y : T
+>y : any
 >t : T
 }
 /** @return {this} */
diff --git a/tests/baselines/reference/typeFromJSConstructor.errors.txt b/tests/baselines/reference/typeFromJSConstructor.errors.txt
index ffcf5393f516d..d77ca8ebd165d 100644
--- a/tests/baselines/reference/typeFromJSConstructor.errors.txt
+++ b/tests/baselines/reference/typeFromJSConstructor.errors.txt
@@ -1,12 +1,13 @@
 tests/cases/conformance/salsa/a.js(10,5): error TS7008: Member 'twices' implicitly has an 'any[]' type.
 tests/cases/conformance/salsa/a.js(14,5): error TS2322: Type '"hi"' is not assignable to type 'number'.
+tests/cases/conformance/salsa/a.js(17,5): error TS2322: Type 'undefined' is not assignable to type 'string'.
 tests/cases/conformance/salsa/a.js(21,5): error TS2322: Type 'false' is not assignable to type 'number'.
-tests/cases/conformance/salsa/a.js(24,5): error TS2322: Type 'null' is not assignable to type 'string | undefined'.
-tests/cases/conformance/salsa/a.js(25,5): error TS2322: Type 'false' is not assignable to type 'string | undefined'.
+tests/cases/conformance/salsa/a.js(24,5): error TS2322: Type 'null' is not assignable to type 'string'.
+tests/cases/conformance/salsa/a.js(25,5): error TS2322: Type 'false' is not assignable to type 'string'.
 tests/cases/conformance/salsa/a.js(26,5): error TS2531: Object is possibly 'null'.
 
 
-==== tests/cases/conformance/salsa/a.js (6 errors) ====
+==== tests/cases/conformance/salsa/a.js (7 errors) ====
     function Installer () {
         // arg: number
         this.arg = 0
@@ -28,6 +29,8 @@ tests/cases/conformance/salsa/a.js(26,5): error TS2531: Object is possibly 'null
         this.unknown = 'hi' // ok
         this.newProperty = 1 // ok: number | boolean
         this.twice = undefined // ok
+        ~~~~~~~~~~
+!!! error TS2322: Type 'undefined' is not assignable to type 'string'.
         this.twice = 'hi' // ok
     }
     Installer.prototype.second = function () {
@@ -38,10 +41,10 @@ tests/cases/conformance/salsa/a.js(26,5): error TS2531: Object is possibly 'null
         this.newProperty = false // ok
         this.twice = null // error
         ~~~~~~~~~~
-!!! error TS2322: Type 'null' is not assignable to type 'string | undefined'.
+!!! error TS2322: Type 'null' is not assignable to type 'string'.
         this.twice = false // error
         ~~~~~~~~~~
-!!! error TS2322: Type 'false' is not assignable to type 'string | undefined'.
+!!! error TS2322: Type 'false' is not assignable to type 'string'.
         this.twices.push(1) // error: Object is possibly null
         ~~~~~~~~~~~
 !!! error TS2531: Object is possibly 'null'.
diff --git a/tests/baselines/reference/typeFromJSConstructor.types b/tests/baselines/reference/typeFromJSConstructor.types
index 38d736e5a688c..68bd498f0f265 100644
--- a/tests/baselines/reference/typeFromJSConstructor.types
+++ b/tests/baselines/reference/typeFromJSConstructor.types
@@ -80,16 +80,16 @@ Installer.prototype.first = function () {
 
     this.twice = undefined // ok
 >this.twice = undefined : undefined
->this.twice : string | undefined
+>this.twice : string
 >this : this
->twice : string | undefined
+>twice : string
 >undefined : undefined
 
     this.twice = 'hi' // ok
 >this.twice = 'hi' : "hi"
->this.twice : string | undefined
+>this.twice : string
 >this : this
->twice : string | undefined
+>twice : string
 >'hi' : "hi"
 }
 Installer.prototype.second = function () {
@@ -124,16 +124,16 @@ Installer.prototype.second = function () {
 
     this.twice = null // error
 >this.twice = null : null
->this.twice : string | undefined
+>this.twice : string
 >this : this
->twice : string | undefined
+>twice : string
 >null : null
 
     this.twice = false // error
 >this.twice = false : false
->this.twice : string | undefined
+>this.twice : string
 >this : this
->twice : string | undefined
+>twice : string
 >false : false
 
     this.twices.push(1) // error: Object is possibly null
diff --git a/tests/baselines/reference/typeFromParamTagForFunction.types b/tests/baselines/reference/typeFromParamTagForFunction.types
index 476c6c3c4539e..2c454f3e0da4b 100644
--- a/tests/baselines/reference/typeFromParamTagForFunction.types
+++ b/tests/baselines/reference/typeFromParamTagForFunction.types
@@ -50,9 +50,9 @@ exports.B = class {
     constructor() {
         this.x = 1;
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
     }
 };
@@ -135,9 +135,9 @@ export class E {
     constructor() {
         this.x = 1;
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
     }
 }
@@ -206,9 +206,9 @@ class H {
     constructor() {
         this.x = 1;
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/typeFromPropertyAssignment15.types b/tests/baselines/reference/typeFromPropertyAssignment15.types
index e1573a21e758b..c82b777396eee 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment15.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment15.types
@@ -13,9 +13,9 @@ Outer.Inner = class {
     constructor() {
         this.x = 1
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
     }
     m() { }
diff --git a/tests/baselines/reference/typeFromPropertyAssignment2.types b/tests/baselines/reference/typeFromPropertyAssignment2.types
index c7f5619ab67c6..aa06b79f4844b 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment2.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment2.types
@@ -20,9 +20,9 @@ Outer.Inner = class I {
     constructor() {
         this.x = 1
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/typeFromPropertyAssignment23.types b/tests/baselines/reference/typeFromPropertyAssignment23.types
index 03bf1d91776c2..d100f71884056 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment23.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment23.types
@@ -5,9 +5,9 @@ class B {
     constructor () {
         this.n = 1
 >this.n = 1 : 1
->this.n : number
+>this.n : any
 >this : this
->n : number
+>n : any
 >1 : 1
     }
     foo() {
diff --git a/tests/baselines/reference/typeFromPropertyAssignment25.types b/tests/baselines/reference/typeFromPropertyAssignment25.types
index d27b4a70165c2..e5ec6cf6f04fe 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment25.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment25.types
@@ -13,9 +13,9 @@ Common.I = class {
     constructor() {
         this.i = 1
 >this.i = 1 : 1
->this.i : number
+>this.i : any
 >this : this
->i : number
+>i : any
 >1 : 1
     }
 }
@@ -36,9 +36,9 @@ Common.O = class extends Common.I {
 
         this.o = 2
 >this.o = 2 : 2
->this.o : number
+>this.o : any
 >this : this
->o : number
+>o : any
 >2 : 2
     }
 }
diff --git a/tests/baselines/reference/typeFromPropertyAssignment26.types b/tests/baselines/reference/typeFromPropertyAssignment26.types
index a6bc478348842..dc01eed98d830 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment26.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment26.types
@@ -13,9 +13,9 @@ UI.TreeElement = class {
     constructor() {
         this.treeOutline = 12
 >this.treeOutline = 12 : 12
->this.treeOutline : number
+>this.treeOutline : any
 >this : this
->treeOutline : number
+>treeOutline : any
 >12 : 12
     }
 };
diff --git a/tests/baselines/reference/typeFromPropertyAssignment28.types b/tests/baselines/reference/typeFromPropertyAssignment28.types
index dc25e6426be5c..a84ea102a87cb 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment28.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment28.types
@@ -3,9 +3,9 @@
 class C { constructor() { this.p = 1; } }
 >C : C
 >this.p = 1 : 1
->this.p : number
+>this.p : any
 >this : this
->p : number
+>p : any
 >1 : 1
 
 // Property assignment does nothing.
diff --git a/tests/baselines/reference/typeFromPropertyAssignment3.types b/tests/baselines/reference/typeFromPropertyAssignment3.types
index 3c3e34b518abd..510296439c894 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment3.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment3.types
@@ -22,9 +22,9 @@ Outer.Inner = class I {
     constructor() {
         this.x = 1
 >this.x = 1 : 1
->this.x : number
+>this.x : any
 >this : this
->x : number
+>x : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/typeFromPropertyAssignment35.types b/tests/baselines/reference/typeFromPropertyAssignment35.types
index 4eebf48bbc168..78f1dfd6224ad 100644
--- a/tests/baselines/reference/typeFromPropertyAssignment35.types
+++ b/tests/baselines/reference/typeFromPropertyAssignment35.types
@@ -34,9 +34,9 @@ Emu.D = class {
     constructor() {
         this._model = 1
 >this._model = 1 : 1
->this._model : number
+>this._model : any
 >this : this
->_model : number
+>_model : any
 >1 : 1
     }
 }
diff --git a/tests/baselines/reference/typeFromPrototypeAssignment.types b/tests/baselines/reference/typeFromPrototypeAssignment.types
index 1e8aee1e1badb..b6d501697a58a 100644
--- a/tests/baselines/reference/typeFromPrototypeAssignment.types
+++ b/tests/baselines/reference/typeFromPrototypeAssignment.types
@@ -8,9 +8,9 @@ var Multimap = function() {
 
     this._map = {};
 >this._map = {} : {}
->this._map : {}
+>this._map : any
 >this : this
->_map : {}
+>_map : any
 >{} : {}
 
     this._map
diff --git a/tests/baselines/reference/typeFromPrototypeAssignment2.types b/tests/baselines/reference/typeFromPrototypeAssignment2.types
index 1a484ba8fc8bf..5f26d98200aca 100644
--- a/tests/baselines/reference/typeFromPrototypeAssignment2.types
+++ b/tests/baselines/reference/typeFromPrototypeAssignment2.types
@@ -13,9 +13,9 @@
 
         this._map = {};
 >this._map = {} : {}
->this._map : {}
+>this._map : any
 >this : this
->_map : {}
+>_map : any
 >{} : {}
 
         this._map
diff --git a/tests/baselines/reference/varRequireFromJavascript.types b/tests/baselines/reference/varRequireFromJavascript.types
index 7537eecb6396a..f6ef20d1a1505 100644
--- a/tests/baselines/reference/varRequireFromJavascript.types
+++ b/tests/baselines/reference/varRequireFromJavascript.types
@@ -44,9 +44,9 @@ export class Crunch {
 
         this.n = n
 >this.n = n : number
->this.n : number
+>this.n : any
 >this : this
->n : number
+>n : any
 >n : number
     }
     m() {

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