assertNever special-cases nodes with SyntaxKind (#27712)

* assertNever special-cases nodes with SyntaxKind * Fix single-quote lint * Use stringify when not a node
microsoft · Oct 11, 2018 · 4d504f9 · 4d504f9
1 parent 5a126e2
commit 4d504f9
Showing 1 changed file with 3 additions and 2 deletions.
diff --git a/src/compiler/core.ts b/src/compiler/core.ts
@@ -1602,8 +1602,9 @@ namespace ts {
             return value;
         }
 
-        export function assertNever(member: never, message?: string, stackCrawlMark?: AnyFunction): never {
-            return fail(message || `Illegal value: ${member}`, stackCrawlMark || assertNever);
+        export function assertNever(member: never, message = "Illegal value:", stackCrawlMark?: AnyFunction): never {
+            const detail = "kind" in member && "pos" in member ? "SyntaxKind: " + showSyntaxKind(member as Node) : JSON.stringify(member);
+            return fail(`${message} ${detail}`, stackCrawlMark || assertNever);
         }
 
         export function getFunctionName(func: AnyFunction) {