Fixed a crash when computing flow type of destructured never (#57586)

Author: Andarist

src/compiler/checker.ts

@@ -43214,7 +43214,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
     function getIteratedTypeOrElementType(use: IterationUse, inputType: Type, sentType: Type, errorNode: Node | undefined, checkAssignability: boolean): Type | undefined {
         const allowAsyncIterables = (use & IterationUse.AllowsAsyncIterablesFlag) !== 0;
         if (inputType === neverType) {
-            reportTypeNotIterableError(errorNode!, inputType, allowAsyncIterables); // TODO: GH#18217
+            if (errorNode) {
+                reportTypeNotIterableError(errorNode, inputType, allowAsyncIterables);
+            }
             return undefined;
         }
 

tests/baselines/reference/autoTypeAssignedUsingDestructuringFromNeverNoCrash.errors.txt

@@ -0,0 +1,19 @@
+autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts(9,3): error TS2488: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator.
+
+
+==== autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts (1 errors) ====
+    // https://github.com/microsoft/TypeScript/issues/57582
+    
+    declare const b: null;
+    let file;
+    
+    if (b === null) {
+      // empty
+    } else {
+      [file] = b;
+      ~~~~~~
+!!! error TS2488: Type 'never' must have a '[Symbol.iterator]()' method that returns an iterator.
+    }
+    
+    file; // request flow type here
+    

tests/baselines/reference/autoTypeAssignedUsingDestructuringFromNeverNoCrash.symbols

@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts] ////
+
+=== autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts ===
+// https://github.com/microsoft/TypeScript/issues/57582
+
+declare const b: null;
+>b : Symbol(b, Decl(autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts, 2, 13))
+
+let file;
+>file : Symbol(file, Decl(autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts, 3, 3))
+
+if (b === null) {
+>b : Symbol(b, Decl(autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts, 2, 13))
+
+  // empty
+} else {
+  [file] = b;
+>file : Symbol(file, Decl(autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts, 3, 3))
+>b : Symbol(b, Decl(autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts, 2, 13))
+}
+
+file; // request flow type here
+>file : Symbol(file, Decl(autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts, 3, 3))
+

tests/baselines/reference/autoTypeAssignedUsingDestructuringFromNeverNoCrash.types

@@ -0,0 +1,27 @@
+//// [tests/cases/compiler/autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts] ////
+
+=== autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts ===
+// https://github.com/microsoft/TypeScript/issues/57582
+
+declare const b: null;
+>b : null
+
+let file;
+>file : any
+
+if (b === null) {
+>b === null : boolean
+>b : null
+
+  // empty
+} else {
+  [file] = b;
+>[file] = b : never
+>[file] : [any]
+>file : any
+>b : never
+}
+
+file; // request flow type here
+>file : any
+

tests/cases/compiler/autoTypeAssignedUsingDestructuringFromNeverNoCrash.ts

@@ -0,0 +1,15 @@
+// @strict: true
+// @noEmit: true
+
+// https://github.com/microsoft/TypeScript/issues/57582
+
+declare const b: null;
+let file;
+
+if (b === null) {
+  // empty
+} else {
+  [file] = b;
+}
+
+file; // request flow type here