Merge pull request #13192 from slawomir/13063-strictNullChecks-breaks-typeof

#13063 Fix strictNullChecks breaking typeof

src/compiler/checker.ts

@@ -10372,7 +10372,7 @@ namespace ts {
             // the entire control flow graph from the variable's declaration (i.e. when the flow container and
             // declaration container are the same).
             const assumeInitialized = isParameter || isOuterVariable ||
-                type !== autoType && type !== autoArrayType && (!strictNullChecks || (type.flags & TypeFlags.Any) !== 0) ||
+                type !== autoType && type !== autoArrayType && (!strictNullChecks || (type.flags & TypeFlags.Any) !== 0 || isInTypeQuery(node)) ||
                 isInAmbientContext(declaration);
             const flowType = getFlowTypeOfReference(node, type, assumeInitialized, flowContainer);
             // A variable is considered uninitialized when it is possible to analyze the entire control flow graph

tests/baselines/reference/typeofStrictNull.js

@@ -0,0 +1,8 @@
+//// [typeofStrictNull.ts]
+
+let a: number;
+let b: typeof a;
+
+//// [typeofStrictNull.js]
+var a;
+var b;

tests/baselines/reference/typeofStrictNull.symbols

@@ -0,0 +1,9 @@
+=== tests/cases/compiler/typeofStrictNull.ts ===
+
+let a: number;
+>a : Symbol(a, Decl(typeofStrictNull.ts, 1, 3))
+
+let b: typeof a;
+>b : Symbol(b, Decl(typeofStrictNull.ts, 2, 3))
+>a : Symbol(a, Decl(typeofStrictNull.ts, 1, 3))
+

tests/baselines/reference/typeofStrictNull.types

@@ -0,0 +1,9 @@
+=== tests/cases/compiler/typeofStrictNull.ts ===
+
+let a: number;
+>a : number
+
+let b: typeof a;
+>b : number
+>a : number
+

tests/cases/compiler/typeofStrictNull.ts

@@ -0,0 +1,4 @@
+// @strictNullChecks: true
+
+let a: number;
+let b: typeof a;