Fix non-toplevel prototype assignment (#27096)

* Fix non-toplevel prototype assignment

binder was using the wrong node to lookup the containing class type for
prototype assignment, so it incorrectly put the prototype declaration on
the class' symbol.

This correction to the binder in turn required a change in
getJSClassType in the checker. It now has to look at the "prototype"
property for the prototype instead of looking on the class symbol's exports
(which makes no sense).

* Refactor per PR suggestion

src/compiler/binder.ts

@@ -2465,7 +2465,7 @@ namespace ts {
             node.left.parent = node;
             node.right.parent = node;
             const lhs = node.left as PropertyAccessEntityNameExpression;
-            bindPropertyAssignment(lhs, lhs, /*isPrototypeProperty*/ false);
+            bindPropertyAssignment(lhs.expression, lhs, /*isPrototypeProperty*/ false);
         }
 
         /**
@@ -2522,7 +2522,7 @@ namespace ts {
             const isToplevel = isBinaryExpression(propertyAccess.parent)
                 ? getParentOfBinaryExpression(propertyAccess.parent).parent.kind === SyntaxKind.SourceFile
                 : propertyAccess.parent.parent.kind === SyntaxKind.SourceFile;
-            if (!isPrototypeProperty && (!namespaceSymbol || !(namespaceSymbol.flags & SymbolFlags.Namespace)) && isToplevel) {
+            if (isToplevel && !isPrototypeProperty && (!namespaceSymbol || !(namespaceSymbol.flags & SymbolFlags.Namespace))) {
                 // make symbols or add declarations for intermediate containers
                 const flags = SymbolFlags.Module | SymbolFlags.Assignment;
                 const excludeFlags = SymbolFlags.ValueModuleExcludes & ~SymbolFlags.Assignment;

src/compiler/checker.ts

@@ -20203,18 +20203,15 @@ namespace ts {
                 assigned || inferred;
         }
 
-        function getAssignedClassType(symbol: Symbol) {
+        function getAssignedClassType(symbol: Symbol): Type | undefined {
             const decl = symbol.valueDeclaration;
             const assignmentSymbol = decl && decl.parent &&
                 (isFunctionDeclaration(decl) && getSymbolOfNode(decl) ||
                  isBinaryExpression(decl.parent) && getSymbolOfNode(decl.parent.left) ||
                  isVariableDeclaration(decl.parent) && getSymbolOfNode(decl.parent));
-            if (assignmentSymbol) {
-                const prototype = forEach(assignmentSymbol.declarations, getAssignedJSPrototype);
-                if (prototype) {
-                    return checkExpression(prototype);
-                }
-            }
+            const prototype = assignmentSymbol && assignmentSymbol.exports && assignmentSymbol.exports.get("prototype" as __String);
+            const init = prototype && getAssignedJSPrototype(prototype.valueDeclaration);
+            return init ? checkExpression(init) : undefined;
         }
 
         function getAssignedJSPrototype(node: Node) {

tests/baselines/reference/typeFromPrototypeAssignment2.errors.txt

@@ -0,0 +1,47 @@
+tests/cases/conformance/salsa/a.js(28,24): error TS2339: Property 'addon' does not exist on type '{ set: () => void; get(): void; }'.
+
+
+==== tests/cases/conformance/salsa/a.js (1 errors) ====
+    // non top-level:
+    // all references to _map, set, get, addon should be ok
+    (function container() {
+        /** @constructor */
+        var Multimap = function() {
+            this._map = {};
+            this._map
+            this.set
+            this.get
+            this.addon
+        };
+    
+        Multimap.prototype = {
+            set: function() {
+                this._map
+                this.set
+                this.get
+                this.addon
+            },
+            get() {
+                this._map
+                this.set
+                this.get
+                this.addon
+            }
+        }
+    
+        Multimap.prototype.addon = function () {
+                           ~~~~~
+!!! error TS2339: Property 'addon' does not exist on type '{ set: () => void; get(): void; }'.
+            this._map
+            this.set
+            this.get
+            this.addon
+        }
+    
+        var mm = new Multimap();
+        mm._map
+        mm.set
+        mm.get
+        mm.addon
+    });
+    

tests/baselines/reference/typeFromPrototypeAssignment2.symbols

@@ -0,0 +1,127 @@
+=== tests/cases/conformance/salsa/a.js ===
+// non top-level:
+// all references to _map, set, get, addon should be ok
+(function container() {
+>container : Symbol(container, Decl(a.js, 2, 1))
+
+    /** @constructor */
+    var Multimap = function() {
+>Multimap : Symbol(Multimap, Decl(a.js, 4, 7))
+
+        this._map = {};
+>this._map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+>_map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+
+        this._map
+>this._map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+>_map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+
+        this.set
+>this.set : Symbol(set, Decl(a.js, 12, 26))
+>set : Symbol(set, Decl(a.js, 12, 26))
+
+        this.get
+>this.get : Symbol(get, Decl(a.js, 18, 10))
+>get : Symbol(get, Decl(a.js, 18, 10))
+
+        this.addon
+>this.addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+>addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+
+    };
+
+    Multimap.prototype = {
+>Multimap.prototype : Symbol(Multimap.prototype, Decl(a.js, 10, 6))
+>Multimap : Symbol(Multimap, Decl(a.js, 4, 7))
+>prototype : Symbol(Multimap.prototype, Decl(a.js, 10, 6))
+
+        set: function() {
+>set : Symbol(set, Decl(a.js, 12, 26))
+
+            this._map
+>this._map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+>_map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+
+            this.set
+>this.set : Symbol(set, Decl(a.js, 12, 26))
+>set : Symbol(set, Decl(a.js, 12, 26))
+
+            this.get
+>this.get : Symbol(get, Decl(a.js, 18, 10))
+>get : Symbol(get, Decl(a.js, 18, 10))
+
+            this.addon
+>this.addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+>addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+
+        },
+        get() {
+>get : Symbol(get, Decl(a.js, 18, 10))
+
+            this._map
+>this._map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+>_map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+
+            this.set
+>this.set : Symbol(set, Decl(a.js, 12, 26))
+>set : Symbol(set, Decl(a.js, 12, 26))
+
+            this.get
+>this.get : Symbol(get, Decl(a.js, 18, 10))
+>get : Symbol(get, Decl(a.js, 18, 10))
+
+            this.addon
+>this.addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+>addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+        }
+    }
+
+    Multimap.prototype.addon = function () {
+>Multimap.prototype : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+>Multimap : Symbol(Multimap, Decl(a.js, 4, 7))
+>prototype : Symbol(Multimap.prototype, Decl(a.js, 10, 6))
+>addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+
+        this._map
+>this._map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+>_map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+
+        this.set
+>this.set : Symbol(set, Decl(a.js, 12, 26))
+>set : Symbol(set, Decl(a.js, 12, 26))
+
+        this.get
+>this.get : Symbol(get, Decl(a.js, 18, 10))
+>get : Symbol(get, Decl(a.js, 18, 10))
+
+        this.addon
+>this.addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+>addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+    }
+
+    var mm = new Multimap();
+>mm : Symbol(mm, Decl(a.js, 34, 7))
+>Multimap : Symbol(Multimap, Decl(a.js, 4, 7))
+
+    mm._map
+>mm._map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+>mm : Symbol(mm, Decl(a.js, 34, 7))
+>_map : Symbol(Multimap._map, Decl(a.js, 4, 31))
+
+    mm.set
+>mm.set : Symbol(set, Decl(a.js, 12, 26))
+>mm : Symbol(mm, Decl(a.js, 34, 7))
+>set : Symbol(set, Decl(a.js, 12, 26))
+
+    mm.get
+>mm.get : Symbol(get, Decl(a.js, 18, 10))
+>mm : Symbol(mm, Decl(a.js, 34, 7))
+>get : Symbol(get, Decl(a.js, 18, 10))
+
+    mm.addon
+>mm.addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+>mm : Symbol(mm, Decl(a.js, 34, 7))
+>addon : Symbol(Multimap.addon, Decl(a.js, 25, 5))
+
+});
+

tests/baselines/reference/typeFromPrototypeAssignment2.types

@@ -0,0 +1,156 @@
+=== tests/cases/conformance/salsa/a.js ===
+// non top-level:
+// all references to _map, set, get, addon should be ok
+(function container() {
+>(function container() {    /** @constructor */    var Multimap = function() {        this._map = {};        this._map        this.set        this.get        this.addon    };    Multimap.prototype = {        set: function() {            this._map            this.set            this.get            this.addon        },        get() {            this._map            this.set            this.get            this.addon        }    }    Multimap.prototype.addon = function () {        this._map        this.set        this.get        this.addon    }    var mm = new Multimap();    mm._map    mm.set    mm.get    mm.addon}) : () => void
+>function container() {    /** @constructor */    var Multimap = function() {        this._map = {};        this._map        this.set        this.get        this.addon    };    Multimap.prototype = {        set: function() {            this._map            this.set            this.get            this.addon        },        get() {            this._map            this.set            this.get            this.addon        }    }    Multimap.prototype.addon = function () {        this._map        this.set        this.get        this.addon    }    var mm = new Multimap();    mm._map    mm.set    mm.get    mm.addon} : () => void
+>container : () => void
+
+    /** @constructor */
+    var Multimap = function() {
+>Multimap : typeof Multimap
+>function() {        this._map = {};        this._map        this.set        this.get        this.addon    } : typeof Multimap
+
+        this._map = {};
+>this._map = {} : {}
+>this._map : {}
+>this : Multimap & { set: () => void; get(): void; }
+>_map : {}
+>{} : {}
+
+        this._map
+>this._map : {}
+>this : Multimap & { set: () => void; get(): void; }
+>_map : {}
+
+        this.set
+>this.set : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>set : () => void
+
+        this.get
+>this.get : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>get : () => void
+
+        this.addon
+>this.addon : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>addon : () => void
+
+    };
+
+    Multimap.prototype = {
+>Multimap.prototype = {        set: function() {            this._map            this.set            this.get            this.addon        },        get() {            this._map            this.set            this.get            this.addon        }    } : { set: () => void; get(): void; }
+>Multimap.prototype : { set: () => void; get(): void; }
+>Multimap : typeof Multimap
+>prototype : { set: () => void; get(): void; }
+>{        set: function() {            this._map            this.set            this.get            this.addon        },        get() {            this._map            this.set            this.get            this.addon        }    } : { set: () => void; get(): void; }
+
+        set: function() {
+>set : () => void
+>function() {            this._map            this.set            this.get            this.addon        } : () => void
+
+            this._map
+>this._map : {}
+>this : Multimap & { set: () => void; get(): void; }
+>_map : {}
+
+            this.set
+>this.set : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>set : () => void
+
+            this.get
+>this.get : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>get : () => void
+
+            this.addon
+>this.addon : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>addon : () => void
+
+        },
+        get() {
+>get : () => void
+
+            this._map
+>this._map : {}
+>this : Multimap & { set: () => void; get(): void; }
+>_map : {}
+
+            this.set
+>this.set : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>set : () => void
+
+            this.get
+>this.get : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>get : () => void
+
+            this.addon
+>this.addon : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>addon : () => void
+        }
+    }
+
+    Multimap.prototype.addon = function () {
+>Multimap.prototype.addon = function () {        this._map        this.set        this.get        this.addon    } : () => void
+>Multimap.prototype.addon : any
+>Multimap.prototype : { set: () => void; get(): void; }
+>Multimap : typeof Multimap
+>prototype : { set: () => void; get(): void; }
+>addon : any
+>function () {        this._map        this.set        this.get        this.addon    } : () => void
+
+        this._map
+>this._map : {}
+>this : Multimap & { set: () => void; get(): void; }
+>_map : {}
+
+        this.set
+>this.set : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>set : () => void
+
+        this.get
+>this.get : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>get : () => void
+
+        this.addon
+>this.addon : () => void
+>this : Multimap & { set: () => void; get(): void; }
+>addon : () => void
+    }
+
+    var mm = new Multimap();
+>mm : Multimap & { set: () => void; get(): void; }
+>new Multimap() : Multimap & { set: () => void; get(): void; }
+>Multimap : typeof Multimap
+
+    mm._map
+>mm._map : {}
+>mm : Multimap & { set: () => void; get(): void; }
+>_map : {}
+
+    mm.set
+>mm.set : () => void
+>mm : Multimap & { set: () => void; get(): void; }
+>set : () => void
+
+    mm.get
+>mm.get : () => void
+>mm : Multimap & { set: () => void; get(): void; }
+>get : () => void
+
+    mm.addon
+>mm.addon : () => void
+>mm : Multimap & { set: () => void; get(): void; }
+>addon : () => void
+
+});
+

tests/cases/conformance/salsa/typeFromPrototypeAssignment2.ts

@@ -0,0 +1,46 @@
+// @noEmit: true
+// @allowJs: true
+// @checkJs: true
+// @Filename: a.js
+// @strict: true
+
+// non top-level:
+// all references to _map, set, get, addon should be ok
+(function container() {
+    /** @constructor */
+    var Multimap = function() {
+        this._map = {};
+        this._map
+        this.set
+        this.get
+        this.addon
+    };
+
+    Multimap.prototype = {
+        set: function() {
+            this._map
+            this.set
+            this.get
+            this.addon
+        },
+        get() {
+            this._map
+            this.set
+            this.get
+            this.addon
+        }
+    }
+
+    Multimap.prototype.addon = function () {
+        this._map
+        this.set
+        this.get
+        this.addon
+    }
+
+    var mm = new Multimap();
+    mm._map
+    mm.set
+    mm.get
+    mm.addon
+});