Assert getExportEqualsLocalSymbol returns a defined result (microsoft#21831)

Andy · web-flow · commit 1b620886a910 · 2018-02-09T10:28:31.000-08:00
diff --git a/src/services/importTracker.ts b/src/services/importTracker.ts
@@ -577,17 +577,17 @@ namespace ts.FindAllReferences {
 
     function getExportEqualsLocalSymbol(importedSymbol: Symbol, checker: TypeChecker): Symbol {
         if (importedSymbol.flags & SymbolFlags.Alias) {
-            return checker.getImmediateAliasedSymbol(importedSymbol);
+            return Debug.assertDefined(checker.getImmediateAliasedSymbol(importedSymbol));
         }
 
         const decl = importedSymbol.valueDeclaration;
         if (isExportAssignment(decl)) { // `export = class {}`
-            return decl.expression.symbol;
+            return Debug.assertDefined(decl.expression.symbol);
         }
         else if (isBinaryExpression(decl)) { // `module.exports = class {}`
-            return decl.right.symbol;
+            return Debug.assertDefined(decl.right.symbol);
         }
-        Debug.fail();
+        return Debug.fail();
     }
 
     // If a reference is a class expression, the exported node would be its parent.

Original file line number	Diff line number	Diff line change
`@@ -577,17 +577,17 @@ namespace ts.FindAllReferences {`
`577`	`577`
`578`	`578`	`function getExportEqualsLocalSymbol(importedSymbol: Symbol, checker: TypeChecker): Symbol {`
`579`	`579`	`if (importedSymbol.flags & SymbolFlags.Alias) {`
`580`		`- return checker.getImmediateAliasedSymbol(importedSymbol);`
	`580`	`+ return Debug.assertDefined(checker.getImmediateAliasedSymbol(importedSymbol));`
`581`	`581`	`}`
`582`	`582`
`583`	`583`	`const decl = importedSymbol.valueDeclaration;`
`584`	`584`	if (isExportAssignment(decl)) { // `export = class {}`
`585`		`- return decl.expression.symbol;`
	`585`	`+ return Debug.assertDefined(decl.expression.symbol);`
`586`	`586`	`}`
`587`	`587`	else if (isBinaryExpression(decl)) { // `module.exports = class {}`
`588`		`- return decl.right.symbol;`
	`588`	`+ return Debug.assertDefined(decl.right.symbol);`
`589`	`589`	`}`
`590`		`- Debug.fail();`
	`590`	`+ return Debug.fail();`
`591`	`591`	`}`
`592`	`592`
`593`	`593`	`// If a reference is a class expression, the exported node would be its parent.`