use Debug.assertDefined

mhegazy · mhegazy · commit 1f69c4885026 · 2018-05-02T09:14:44.000-07:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -3609,7 +3609,7 @@ namespace ts {
                 let chain: Symbol[];
                 const isTypeParameter = symbol.flags & SymbolFlags.TypeParameter;
                 if (!isTypeParameter && (context.enclosingDeclaration || context.flags & NodeBuilderFlags.UseFullyQualifiedType)) {
-                    chain = getSymbolChain(symbol, meaning, /*endOfChain*/ true)!;
+                    chain = Debug.assertDefined(getSymbolChain(symbol, meaning, /*endOfChain*/ true));
                     Debug.assert(chain && chain.length > 0);
                 }
                 else {

Original file line number	Diff line number	Diff line change
`@@ -3609,7 +3609,7 @@ namespace ts {`
`3609`	`3609`	`let chain: Symbol[];`
`3610`	`3610`	`const isTypeParameter = symbol.flags & SymbolFlags.TypeParameter;`
`3611`	`3611`	`if (!isTypeParameter && (context.enclosingDeclaration \|\| context.flags & NodeBuilderFlags.UseFullyQualifiedType)) {`
`3612`		`- chain = getSymbolChain(symbol, meaning, /endOfChain/ true)!;`
	`3612`	`+ chain = Debug.assertDefined(getSymbolChain(symbol, meaning, /endOfChain/ true));`
`3613`	`3613`	`Debug.assert(chain && chain.length > 0);`
`3614`	`3614`	`}`
`3615`	`3615`	`else {`