Fix expando handling in getTypeReferenceType (microsoft#34712)

* Fix expando handling in getTypeReferenceType

getExpandoSymbol looks for the initialiser of a symbol when it is an
expando value (IIFEs, function exprs, class exprs and empty object
literals) and returns the symbol.

Previously, however, it returned the symbol of the initialiser without
merging with the declaration symbol itself. This missed, in particular,
the prototype assignment in the following pattern:

```js
var x = function x() {
  this.y = 1
}
x.prototype = {
  z() { }
}

/** @type {x} */
var xx;
xx.z // missed!
```

getJSDocValueReference had weird try-again code that relied on calling
getTypeOfSymbol, which *does* correctly merge the symbols. This PR
re-removes that code and instead makes getExpandoSymbol call
mergeJSSymbols itself.

* Remove extra newline

Author: sandersn

src/compiler/checker.ts

@@ -2629,7 +2629,12 @@ namespace ts {
                 return undefined;
             }
             const init = isVariableDeclaration(decl) ? getDeclaredExpandoInitializer(decl) : getAssignedExpandoInitializer(decl);
-            return init && getSymbolOfNode(init) || undefined;
+            if (init) {
+                const initSymbol = getSymbolOfNode(init);
+                if (initSymbol) {
+                    return mergeJSSymbols(initSymbol, symbol);
+                }
+            }
         }
 
 
@@ -10766,9 +10771,7 @@ namespace ts {
                     && isCallExpression(decl.initializer)
                     && isRequireCall(decl.initializer, /*requireStringLiteralLikeArgument*/ true)
                     && valueType.symbol;
-                const isImportType = node.kind === SyntaxKind.ImportType;
-                const isDelayedMergeClass = symbol !== valueType.symbol && getMergedSymbol(symbol) === valueType.symbol;
-                if (isRequireAlias || isImportType || isDelayedMergeClass) {
+                if (isRequireAlias || node.kind === SyntaxKind.ImportType) {
                     typeType = getTypeReferenceType(node, valueType.symbol);
                 }
             }
@@ -24997,7 +25000,7 @@ namespace ts {
         }
 
         function mergeJSSymbols(target: Symbol, source: Symbol | undefined) {
-            if (source && (hasEntries(source.exports) || hasEntries(source.members))) {
+            if (source) {
                 const links = getSymbolLinks(source);
                 if (!links.inferredClassSymbol || !links.inferredClassSymbol.has("" + getSymbolId(target))) {
                     const inferred = isTransientSymbol(target) ? target : cloneSymbol(target) as TransientSymbol;

tests/baselines/reference/jsdocTypeReferenceToMergedClass.symbols

@@ -1,35 +1,32 @@
-=== tests/cases/conformance/jsdoc/test.js ===
+=== tests/cases/conformance/jsdoc/jsdocTypeReferenceToMergedClass.js ===
 // https://github.com/microsoft/TypeScript/issues/34685
 
-/** @param {Workspace.Project} p */
-function demo(p) {
->demo : Symbol(demo, Decl(test.js, 0, 0))
->p : Symbol(p, Decl(test.js, 3, 14))
-
-    p.isServiceProject()
->p.isServiceProject : Symbol(isServiceProject, Decl(mod1.js, 3, 31))
->p : Symbol(p, Decl(test.js, 3, 14))
->isServiceProject : Symbol(isServiceProject, Decl(mod1.js, 3, 31))
-}
-=== tests/cases/conformance/jsdoc/mod1.js ===
-// Note: mod1.js needs to appear second to trigger the bug
 var Workspace = {}
->Workspace : Symbol(Workspace, Decl(mod1.js, 1, 3), Decl(mod1.js, 1, 18), Decl(mod1.js, 2, 37))
+>Workspace : Symbol(Workspace, Decl(jsdocTypeReferenceToMergedClass.js, 2, 3), Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 7, 37))
+
+/** @type {Workspace.Project} */
+var p;
+>p : Symbol(p, Decl(jsdocTypeReferenceToMergedClass.js, 4, 3))
+
+p.isServiceProject()
+>p.isServiceProject : Symbol(isServiceProject, Decl(jsdocTypeReferenceToMergedClass.js, 8, 31))
+>p : Symbol(p, Decl(jsdocTypeReferenceToMergedClass.js, 4, 3))
+>isServiceProject : Symbol(isServiceProject, Decl(jsdocTypeReferenceToMergedClass.js, 8, 31))
 
 Workspace.Project = function wp() { }
->Workspace.Project : Symbol(Workspace.Project, Decl(mod1.js, 1, 18), Decl(mod1.js, 3, 10))
->Workspace : Symbol(Workspace, Decl(mod1.js, 1, 3), Decl(mod1.js, 1, 18), Decl(mod1.js, 2, 37))
->Project : Symbol(Workspace.Project, Decl(mod1.js, 1, 18), Decl(mod1.js, 3, 10))
->wp : Symbol(wp, Decl(mod1.js, 2, 19))
+>Workspace.Project : Symbol(Workspace.Project, Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 8, 10))
+>Workspace : Symbol(Workspace, Decl(jsdocTypeReferenceToMergedClass.js, 2, 3), Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 7, 37))
+>Project : Symbol(Workspace.Project, Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 8, 10))
+>wp : Symbol(wp, Decl(jsdocTypeReferenceToMergedClass.js, 7, 19))
 
 Workspace.Project.prototype = {
->Workspace.Project.prototype : Symbol(Workspace.Project.prototype, Decl(mod1.js, 2, 37))
->Workspace.Project : Symbol(Workspace.Project, Decl(mod1.js, 1, 18), Decl(mod1.js, 3, 10))
->Workspace : Symbol(Workspace, Decl(mod1.js, 1, 3), Decl(mod1.js, 1, 18), Decl(mod1.js, 2, 37))
->Project : Symbol(Workspace.Project, Decl(mod1.js, 1, 18), Decl(mod1.js, 3, 10))
->prototype : Symbol(Workspace.Project.prototype, Decl(mod1.js, 2, 37))
+>Workspace.Project.prototype : Symbol(Workspace.Project.prototype, Decl(jsdocTypeReferenceToMergedClass.js, 7, 37))
+>Workspace.Project : Symbol(Workspace.Project, Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 8, 10))
+>Workspace : Symbol(Workspace, Decl(jsdocTypeReferenceToMergedClass.js, 2, 3), Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 7, 37))
+>Project : Symbol(Workspace.Project, Decl(jsdocTypeReferenceToMergedClass.js, 5, 20), Decl(jsdocTypeReferenceToMergedClass.js, 8, 10))
+>prototype : Symbol(Workspace.Project.prototype, Decl(jsdocTypeReferenceToMergedClass.js, 7, 37))
 
   isServiceProject() {}
->isServiceProject : Symbol(isServiceProject, Decl(mod1.js, 3, 31))
+>isServiceProject : Symbol(isServiceProject, Decl(jsdocTypeReferenceToMergedClass.js, 8, 31))
 }
 

tests/baselines/reference/jsdocTypeReferenceToMergedClass.types

@@ -1,22 +1,19 @@
-=== tests/cases/conformance/jsdoc/test.js ===
+=== tests/cases/conformance/jsdoc/jsdocTypeReferenceToMergedClass.js ===
 // https://github.com/microsoft/TypeScript/issues/34685
 
-/** @param {Workspace.Project} p */
-function demo(p) {
->demo : (p: wp) => void
+var Workspace = {}
+>Workspace : typeof Workspace
+>{} : {}
+
+/** @type {Workspace.Project} */
+var p;
 >p : wp
 
-    p.isServiceProject()
+p.isServiceProject()
 >p.isServiceProject() : void
 >p.isServiceProject : () => void
 >p : wp
 >isServiceProject : () => void
-}
-=== tests/cases/conformance/jsdoc/mod1.js ===
-// Note: mod1.js needs to appear second to trigger the bug
-var Workspace = {}
->Workspace : typeof Workspace
->{} : {}
 
 Workspace.Project = function wp() { }
 >Workspace.Project = function wp() { } : typeof wp

tests/cases/conformance/jsdoc/jsdocTypeReferenceToMergedClass.ts

@@ -3,14 +3,12 @@
 // @allowJs: true
 // @checkJs: true
 
-// @Filename: test.js
-/** @param {Workspace.Project} p */
-function demo(p) {
-    p.isServiceProject()
-}
-// @Filename: mod1.js
-// Note: mod1.js needs to appear second to trigger the bug
+// @Filename: jsdocTypeReferenceToMergedClass.js
 var Workspace = {}
+/** @type {Workspace.Project} */
+var p;
+p.isServiceProject()
+
 Workspace.Project = function wp() { }
 Workspace.Project.prototype = {
   isServiceProject() {}