Fix duplicate errors in js special assignments (microsoft#24508)

* Fix duplicate errors in js special assignments

* Simplify checkExpressionCached call to checkExpression

* Accept baselines after merge

* Use Map for deferredNodes and improve NoDeferredCheck comment

I added an assert when a duplicate was added, but it caused 18 failures
in our test suite.

* Remove NoDeferredCheck

Author: sandersn

src/compiler/checker.ts

@@ -465,7 +465,7 @@ namespace ts {
         let deferredGlobalImportMetaType: ObjectType;
         let deferredGlobalExtractSymbol: Symbol;
 
-        let deferredNodes: Node[] | undefined;
+        let deferredNodes: Map<Node> | undefined;
         const allPotentiallyUnusedIdentifiers = createMap<PotentiallyUnusedIdentifier[]>(); // key is file name
 
         let flowLoopStart = 0;
@@ -26070,12 +26070,13 @@ namespace ts {
         // Delaying the type check of the body ensures foo has been assigned a type.
         function checkNodeDeferred(node: Node) {
             if (deferredNodes) {
-                deferredNodes.push(node);
+                const id = "" + getNodeId(node);
+                deferredNodes.set(id, node);
             }
         }
 
         function checkDeferredNodes() {
-            for (const node of deferredNodes!) {
+            deferredNodes!.forEach(node => {
                 switch (node.kind) {
                     case SyntaxKind.FunctionExpression:
                     case SyntaxKind.ArrowFunction:
@@ -26091,7 +26092,7 @@ namespace ts {
                         checkClassExpressionDeferred(<ClassExpression>node);
                         break;
                 }
-            }
+            });
         }
 
         function checkSourceFile(node: SourceFile) {
@@ -26133,7 +26134,7 @@ namespace ts {
                 clear(potentialThisCollisions);
                 clear(potentialNewTargetCollisions);
 
-                deferredNodes = [];
+                deferredNodes = createMap<Node>();
                 forEach(node.statements, checkSourceElement);
 
                 checkDeferredNodes();

tests/baselines/reference/checkSpecialPropertyAssignments.errors.txt

@@ -0,0 +1,19 @@
+tests/cases/conformance/salsa/bug24252.js(8,9): error TS2322: Type 'string[]' is not assignable to type 'number[]'.
+  Type 'string' is not assignable to type 'number'.
+
+
+==== tests/cases/conformance/salsa/bug24252.js (1 errors) ====
+    var A = {};
+    A.B = class {
+        m() {
+            /** @type {string[]} */
+            var x = [];
+            /** @type {number[]} */
+            var y;
+            y = x;
+            ~
+!!! error TS2322: Type 'string[]' is not assignable to type 'number[]'.
+!!! error TS2322:   Type 'string' is not assignable to type 'number'.
+        }
+    };
+    

tests/baselines/reference/checkSpecialPropertyAssignments.symbols

@@ -0,0 +1,26 @@
+=== tests/cases/conformance/salsa/bug24252.js ===
+var A = {};
+>A : Symbol(A, Decl(bug24252.js, 0, 3), Decl(bug24252.js, 0, 11))
+
+A.B = class {
+>A.B : Symbol(A.B, Decl(bug24252.js, 0, 11))
+>A : Symbol(A, Decl(bug24252.js, 0, 3), Decl(bug24252.js, 0, 11))
+>B : Symbol(A.B, Decl(bug24252.js, 0, 11))
+
+    m() {
+>m : Symbol(B.m, Decl(bug24252.js, 1, 13))
+
+        /** @type {string[]} */
+        var x = [];
+>x : Symbol(x, Decl(bug24252.js, 4, 11))
+
+        /** @type {number[]} */
+        var y;
+>y : Symbol(y, Decl(bug24252.js, 6, 11))
+
+        y = x;
+>y : Symbol(y, Decl(bug24252.js, 6, 11))
+>x : Symbol(x, Decl(bug24252.js, 4, 11))
+    }
+};
+

tests/baselines/reference/checkSpecialPropertyAssignments.types

@@ -0,0 +1,31 @@
+=== tests/cases/conformance/salsa/bug24252.js ===
+var A = {};
+>A : typeof A
+>{} : { [x: string]: any; }
+
+A.B = class {
+>A.B = class {    m() {        /** @type {string[]} */        var x = [];        /** @type {number[]} */        var y;        y = x;    }} : typeof B
+>A.B : typeof B
+>A : typeof A
+>B : typeof B
+>class {    m() {        /** @type {string[]} */        var x = [];        /** @type {number[]} */        var y;        y = x;    }} : typeof B
+
+    m() {
+>m : () => void
+
+        /** @type {string[]} */
+        var x = [];
+>x : string[]
+>[] : undefined[]
+
+        /** @type {number[]} */
+        var y;
+>y : number[]
+
+        y = x;
+>y = x : string[]
+>y : number[]
+>x : string[]
+    }
+};
+

tests/cases/conformance/salsa/checkSpecialPropertyAssignments.ts

@@ -0,0 +1,14 @@
+// @noEmit: true
+// @checkJs: true
+// @allowJs: true
+// @Filename: bug24252.js
+var A = {};
+A.B = class {
+    m() {
+        /** @type {string[]} */
+        var x = [];
+        /** @type {number[]} */
+        var y;
+        y = x;
+    }
+};