fix(49566): Implicit this.property completions not returned while writing property (#49574)

* fix(49566): show this.prop completions in class scoped property declaration

* remove duplicate default value

Author: a-tarasyuk

Diff for: src/compiler/checker.ts

@@ -672,9 +672,9 @@ namespace ts {
                 return moduleSpecifier && resolveExternalModuleName(moduleSpecifier, moduleSpecifier, /*ignoreErrors*/ true);
             },
             resolveExternalModuleSymbol,
-            tryGetThisTypeAt: (nodeIn, includeGlobalThis) => {
+            tryGetThisTypeAt: (nodeIn, includeGlobalThis, container) => {
                 const node = getParseTreeNode(nodeIn);
-                return node && tryGetThisTypeAt(node, includeGlobalThis);
+                return node && tryGetThisTypeAt(node, includeGlobalThis, container);
             },
             getTypeArgumentConstraint: nodeIn => {
                 const node = getParseTreeNode(nodeIn, isTypeNode);

Diff for: src/compiler/types.ts

@@ -4597,7 +4597,7 @@ namespace ts {
          */
         /* @internal */ resolveExternalModuleSymbol(symbol: Symbol): Symbol;
         /** @param node A location where we might consider accessing `this`. Not necessarily a ThisExpression. */
-        /* @internal */ tryGetThisTypeAt(node: Node, includeGlobalThis?: boolean): Type | undefined;
+        /* @internal */ tryGetThisTypeAt(node: Node, includeGlobalThis?: boolean, container?: Node): Type | undefined;
         /* @internal */ getTypeArgumentConstraint(node: TypeNode): Type | undefined;
 
         /**

Diff for: src/services/completions.ts

@@ -2616,7 +2616,7 @@ namespace ts.Completions {
 
             // Need to insert 'this.' before properties of `this` type, so only do that if `includeInsertTextCompletions`
             if (preferences.includeCompletionsWithInsertText && scopeNode.kind !== SyntaxKind.SourceFile) {
-                const thisType = typeChecker.tryGetThisTypeAt(scopeNode, /*includeGlobalThis*/ false);
+                const thisType = typeChecker.tryGetThisTypeAt(scopeNode, /*includeGlobalThis*/ false, isClassLike(scopeNode.parent) ? scopeNode : undefined);
                 if (thisType && !isProbablyGlobalType(thisType, sourceFile, typeChecker)) {
                     for (const symbol of getPropertiesForCompletion(thisType, typeChecker)) {
                         symbolToOriginInfoMap[symbols.length] = { kind: SymbolOriginInfoKind.ThisType };

Diff for: tests/cases/fourslash/completionsThisPropertiesInPropertyDeclaration1.ts

@@ -0,0 +1,28 @@
+/// <reference path="fourslash.ts" />
+
+////class Foo {
+////    private _prop = 1;
+////    public a = [|_/*1*/|]
+////
+////    foo() {
+////        [|_/*2*/|]
+////    }
+////}
+
+verify.completions({
+    marker: ["1", "2"],
+    includes: [
+        {
+            name: "_prop",
+            insertText: "this._prop",
+            kind: "property",
+            sortText: completion.SortText.SuggestedClassMembers,
+            source: completion.CompletionSource.ThisProperty,
+            text: "(property) Foo._prop: number",
+            kindModifiers: "private"
+        },
+    ],
+    preferences: {
+        includeInsertTextCompletions: true
+    }
+});

Diff for: tests/cases/fourslash/completionsThisPropertiesInPropertyDeclaration2.ts

@@ -0,0 +1,28 @@
+/// <reference path="fourslash.ts" />
+
+////class Foo {
+////    private static _prop = 1;
+////    public static a = [|_/*1*/|]
+////
+////    static foo() {
+////        [|_/*2*/|]
+////    }
+////}
+
+verify.completions({
+    marker: ["2"],
+    includes: [
+        {
+            name: "_prop",
+            insertText: "this._prop",
+            kind: "property",
+            sortText: completion.SortText.SuggestedClassMembers,
+            source: completion.CompletionSource.ThisProperty,
+            text: "(property) Foo._prop: number",
+            kindModifiers: "private,static"
+        },
+    ],
+    preferences: {
+        includeInsertTextCompletions: true
+    }
+});