From e83fd2637fa1270c9a2202e0cd3053bdc39ae7a2 Mon Sep 17 00:00:00 2001
From: ShuiRuTian <158983297@qq.com>
Date: Wed, 24 Mar 2021 11:37:59 +0800
Subject: [PATCH 1/3] fix quickinfo of narrowed private filed

---
 src/compiler/checker.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 0a98fd289a390..1644f888115cb 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -23546,7 +23546,7 @@ namespace ts {
             // an dotted name expression, and if the location is not an assignment target, obtain the type
             // of the expression (which will reflect control flow analysis). If the expression indeed
             // resolved to the given symbol, return the narrowed type.
-            if (location.kind === SyntaxKind.Identifier) {
+            if (location.kind === SyntaxKind.Identifier || location.kind === SyntaxKind.PrivateIdentifier) {
                 if (isRightSideOfQualifiedNameOrPropertyAccess(location)) {
                     location = location.parent;
                 }

From d3bd487a9ed43d2ed79f033bbbc70aebab7890cb Mon Sep 17 00:00:00 2001
From: ShuiRuTian <158983297@qq.com>
Date: Wed, 24 Mar 2021 11:50:30 +0800
Subject: [PATCH 2/3] add test case.

---
 tests/cases/fourslash/quickInfoOnNarrowedType.ts | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/tests/cases/fourslash/quickInfoOnNarrowedType.ts b/tests/cases/fourslash/quickInfoOnNarrowedType.ts
index da9a7ba0c7ac1..760c9bde2fffa 100644
--- a/tests/cases/fourslash/quickInfoOnNarrowedType.ts
+++ b/tests/cases/fourslash/quickInfoOnNarrowedType.ts
@@ -18,6 +18,18 @@
 ////   /*6*/s;
 ////}
 
+////class TestClass {
+////    #privateProperty: string[] | null;
+////    constructor() {
+////        this.#privateProperty = null;
+////    }
+////    testMethod() {
+////        if (this.#privateProperty === null)
+////            return;
+////        this./*7*/#privateProperty;
+////    }
+////}
+
 verify.quickInfos({
     1: "(parameter) strOrNum: string | number",
     2: "(parameter) strOrNum: number",
@@ -25,6 +37,7 @@ verify.quickInfos({
     4: "let s: string | undefined",
     5: "let s: string | undefined",
     6: "let s: string",
+    7: "(property) TestClass.#privateProperty: string[]"
 });
 
 verify.completions(
@@ -33,4 +46,5 @@ verify.completions(
     { marker: "3", includes: { name: "strOrNum", text: "(parameter) strOrNum: string" } },
     { marker: ["4", "5"], includes: { name: "s", text: "let s: string | undefined" } },
     { marker: "6", includes: { name: "s", text: "let s: string" } },
+    { marker: "7", includes: { name: "#privateProperty", text: "(property) TestClass.#privateProperty: string[]" } }
 );

From 757d84136cecfb78d3cb247e0f2bd09cde3cf225 Mon Sep 17 00:00:00 2001
From: ShuiRuTian <158983297@qq.com>
Date: Wed, 24 Mar 2021 15:22:24 +0800
Subject: [PATCH 3/3] adapt review.

---
 tests/cases/fourslash/quickInfoOnNarrowedType.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/tests/cases/fourslash/quickInfoOnNarrowedType.ts b/tests/cases/fourslash/quickInfoOnNarrowedType.ts
index 760c9bde2fffa..5b0c9a0f14e36 100644
--- a/tests/cases/fourslash/quickInfoOnNarrowedType.ts
+++ b/tests/cases/fourslash/quickInfoOnNarrowedType.ts
@@ -18,7 +18,7 @@
 ////   /*6*/s;
 ////}
 
-////class TestClass {
+////class Foo {
 ////    #privateProperty: string[] | null;
 ////    constructor() {
 ////        this.#privateProperty = null;
@@ -37,7 +37,7 @@ verify.quickInfos({
     4: "let s: string | undefined",
     5: "let s: string | undefined",
     6: "let s: string",
-    7: "(property) TestClass.#privateProperty: string[]"
+    7: "(property) Foo.#privateProperty: string[]"
 });
 
 verify.completions(
@@ -46,5 +46,5 @@ verify.completions(
     { marker: "3", includes: { name: "strOrNum", text: "(parameter) strOrNum: string" } },
     { marker: ["4", "5"], includes: { name: "s", text: "let s: string | undefined" } },
     { marker: "6", includes: { name: "s", text: "let s: string" } },
-    { marker: "7", includes: { name: "#privateProperty", text: "(property) TestClass.#privateProperty: string[]" } }
+    { marker: "7", includes: { name: "#privateProperty", text: "(property) Foo.#privateProperty: string[]" } }
 );