From 2d2117237cc51857c83618267de35489765b08c3 Mon Sep 17 00:00:00 2001
From: Herrington Darkholme <nonamesheep1@gmail.com>
Date: Sat, 11 Feb 2017 23:38:17 +0800
Subject: [PATCH] fix #11463, null assertion block uninitialized error

---
 src/compiler/checker.ts                            |  2 +-
 .../baselines/reference/typeGuardsAsAssertions.js  |  9 +++++++++
 .../reference/typeGuardsAsAssertions.symbols       | 12 ++++++++++++
 .../reference/typeGuardsAsAssertions.types         | 14 ++++++++++++++
 .../controlFlow/typeGuardsAsAssertions.ts          |  5 +++++
 5 files changed, 41 insertions(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index ac1135788cd1c..97fda44fb3686 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -10582,7 +10582,7 @@ namespace ts {
             // declaration container are the same).
             const assumeInitialized = isParameter || isOuterVariable ||
                 type !== autoType && type !== autoArrayType && (!strictNullChecks || (type.flags & TypeFlags.Any) !== 0 || isInTypeQuery(node)) ||
-                isInAmbientContext(declaration);
+                node.parent.kind === SyntaxKind.NonNullExpression || 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
             // from declaration to use, and when the variable's declared type doesn't include undefined but the
diff --git a/tests/baselines/reference/typeGuardsAsAssertions.js b/tests/baselines/reference/typeGuardsAsAssertions.js
index 84fc996c3ab50..1a59672df77bf 100644
--- a/tests/baselines/reference/typeGuardsAsAssertions.js
+++ b/tests/baselines/reference/typeGuardsAsAssertions.js
@@ -120,6 +120,11 @@ function f6() {
     x = <string | null>"";
     x!.slice();
 }
+
+function f7() {
+    let x: string;
+    x!.slice();
+}
 
 
 //// [typeGuardsAsAssertions.js]
@@ -227,3 +232,7 @@ function f6() {
     x = "";
     x.slice();
 }
+function f7() {
+    var x;
+    x.slice();
+}
diff --git a/tests/baselines/reference/typeGuardsAsAssertions.symbols b/tests/baselines/reference/typeGuardsAsAssertions.symbols
index 5079f3b8cb44a..63aa4f1b01747 100644
--- a/tests/baselines/reference/typeGuardsAsAssertions.symbols
+++ b/tests/baselines/reference/typeGuardsAsAssertions.symbols
@@ -313,3 +313,15 @@ function f6() {
 >slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
 }
 
+function f7() {
+>f7 : Symbol(f7, Decl(typeGuardsAsAssertions.ts, 120, 1))
+
+    let x: string;
+>x : Symbol(x, Decl(typeGuardsAsAssertions.ts, 123, 7))
+
+    x!.slice();
+>x!.slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
+>x : Symbol(x, Decl(typeGuardsAsAssertions.ts, 123, 7))
+>slice : Symbol(String.slice, Decl(lib.d.ts, --, --))
+}
+
diff --git a/tests/baselines/reference/typeGuardsAsAssertions.types b/tests/baselines/reference/typeGuardsAsAssertions.types
index 06dda2691be8e..2ef1e91430193 100644
--- a/tests/baselines/reference/typeGuardsAsAssertions.types
+++ b/tests/baselines/reference/typeGuardsAsAssertions.types
@@ -383,3 +383,17 @@ function f6() {
 >slice : (start?: number | undefined, end?: number | undefined) => string
 }
 
+function f7() {
+>f7 : () => void
+
+    let x: string;
+>x : string
+
+    x!.slice();
+>x!.slice() : string
+>x!.slice : (start?: number | undefined, end?: number | undefined) => string
+>x! : string
+>x : string
+>slice : (start?: number | undefined, end?: number | undefined) => string
+}
+
diff --git a/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts b/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts
index 912eaa64e80de..5ce430bc19a6d 100644
--- a/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts
+++ b/tests/cases/conformance/controlFlow/typeGuardsAsAssertions.ts
@@ -120,3 +120,8 @@ function f6() {
     x = <string | null>"";
     x!.slice();
 }
+
+function f7() {
+    let x: string;
+    x!.slice();
+}