From dfe23421baefa8a3309b231118f894ebfda79190 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Wed, 30 Dec 2020 20:42:38 +0200
Subject: [PATCH] fix(41867): completions - omit the deprecated flag if some
 declarations are not deprecated (#41941)

---
 src/services/symbolDisplay.ts                 | 37 ++++++++++++-------
 src/services/utilities.ts                     |  6 ++-
 ...ag.ts => completionsWithDeprecatedTag1.ts} |  0
 .../completionsWithDeprecatedTag2.ts          | 15 ++++++++
 .../completionsWithDeprecatedTag3.ts          | 15 ++++++++
 5 files changed, 58 insertions(+), 15 deletions(-)
 rename tests/cases/fourslash/{completionsWithDeprecatedTag.ts => completionsWithDeprecatedTag1.ts} (100%)
 create mode 100644 tests/cases/fourslash/completionsWithDeprecatedTag2.ts
 create mode 100644 tests/cases/fourslash/completionsWithDeprecatedTag3.ts

diff --git a/src/services/symbolDisplay.ts b/src/services/symbolDisplay.ts
index 4acba52253a..b1f74800635 100644
--- a/src/services/symbolDisplay.ts
+++ b/src/services/symbolDisplay.ts
@@ -100,31 +100,42 @@ namespace ts.SymbolDisplay {
         return ScriptElementKind.unknown;
     }
 
+    function isDeprecatedDeclaration(decl: Declaration) {
+        return !!(getCombinedNodeFlagsAlwaysIncludeJSDoc(decl) & ModifierFlags.Deprecated);
+    }
+
+    function getNormalizedSymbolModifiers(symbol: Symbol) {
+        if (symbol.declarations && symbol.declarations.length) {
+            const [declaration, ...declarations] = symbol.declarations;
+            // omit deprecated flag if some declarations are not deprecated
+            const excludeFlags = length(declarations) && isDeprecatedDeclaration(declaration) && some(declarations, d => !isDeprecatedDeclaration(d))
+                ? ModifierFlags.Deprecated
+                : ModifierFlags.None;
+            const modifiers = getNodeModifiers(declaration, excludeFlags);
+            if (modifiers) {
+                return modifiers.split(",");
+            }
+        }
+        return [];
+    }
+
     export function getSymbolModifiers(typeChecker: TypeChecker, symbol: Symbol): string {
         if (!symbol) {
             return ScriptElementKindModifier.none;
         }
 
-        const modifiers = new Set<string>();
-        if (symbol.declarations && symbol.declarations.length > 0) {
-            const kindModifiers = getNodeModifiers(symbol.declarations[0]);
-            if (kindModifiers !== ScriptElementKindModifier.none) {
-                kindModifiers.split(",").forEach(m => modifiers.add(m));
-            }
-        }
+        const modifiers = new Set(getNormalizedSymbolModifiers(symbol));
         if (symbol.flags & SymbolFlags.Alias) {
             const resolvedSymbol = typeChecker.getAliasedSymbol(symbol);
-            if (resolvedSymbol !== symbol && resolvedSymbol.declarations && resolvedSymbol.declarations.length > 0) {
-                const kindModifiers = getNodeModifiers(resolvedSymbol.declarations[0]);
-                if (kindModifiers !== ScriptElementKindModifier.none) {
-                    kindModifiers.split(",").forEach(m => modifiers.add(m));
-                }
+            if (resolvedSymbol !== symbol) {
+                forEach(getNormalizedSymbolModifiers(resolvedSymbol), modifier => {
+                    modifiers.add(modifier);
+                });
             }
         }
         if (symbol.flags & SymbolFlags.Optional) {
             modifiers.add(ScriptElementKindModifier.optionalModifier);
         }
-
         return modifiers.size > 0 ? arrayFrom(modifiers.values()).join(",") : ScriptElementKindModifier.none;
     }
 
diff --git a/src/services/utilities.ts b/src/services/utilities.ts
index 9cf63087ebd..d456c414bc7 100644
--- a/src/services/utilities.ts
+++ b/src/services/utilities.ts
@@ -1588,9 +1588,11 @@ namespace ts {
         return n.kind === SyntaxKind.EndOfFileToken ? !!(n as EndOfFileToken).jsDoc : n.getWidth(sourceFile) !== 0;
     }
 
-    export function getNodeModifiers(node: Node): string {
-        const flags = isDeclaration(node) ? getCombinedNodeFlagsAlwaysIncludeJSDoc(node) : ModifierFlags.None;
+    export function getNodeModifiers(node: Node, excludeFlags = ModifierFlags.None): string {
         const result: string[] = [];
+        const flags = isDeclaration(node)
+            ? getCombinedNodeFlagsAlwaysIncludeJSDoc(node) & ~excludeFlags
+            : ModifierFlags.None;
 
         if (flags & ModifierFlags.Private) result.push(ScriptElementKindModifier.privateMemberModifier);
         if (flags & ModifierFlags.Protected) result.push(ScriptElementKindModifier.protectedMemberModifier);
diff --git a/tests/cases/fourslash/completionsWithDeprecatedTag.ts b/tests/cases/fourslash/completionsWithDeprecatedTag1.ts
similarity index 100%
rename from tests/cases/fourslash/completionsWithDeprecatedTag.ts
rename to tests/cases/fourslash/completionsWithDeprecatedTag1.ts
diff --git a/tests/cases/fourslash/completionsWithDeprecatedTag2.ts b/tests/cases/fourslash/completionsWithDeprecatedTag2.ts
new file mode 100644
index 00000000000..a902c6b30eb
--- /dev/null
+++ b/tests/cases/fourslash/completionsWithDeprecatedTag2.ts
@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+/////** @deprecated foo */
+////declare function foo<T>();
+/////** @deprecated foo<T> */
+////declare function foo<T>(x);
+////
+////foo/**/
+
+verify.completions({
+    marker: "",
+    includes: [
+        { name: "foo", kind: "function", kindModifiers: "deprecated,declare" }
+    ]
+});
diff --git a/tests/cases/fourslash/completionsWithDeprecatedTag3.ts b/tests/cases/fourslash/completionsWithDeprecatedTag3.ts
new file mode 100644
index 00000000000..19e9d5c561b
--- /dev/null
+++ b/tests/cases/fourslash/completionsWithDeprecatedTag3.ts
@@ -0,0 +1,15 @@
+/// <reference path="fourslash.ts" />
+
+/////** @deprecated foo */
+////declare function foo<T>();
+/////** ok */
+////declare function foo<T>(x);
+////
+////foo/**/
+
+verify.completions({
+    marker: "",
+    includes: [
+      { name: "foo", kind: "function", kindModifiers: "declare" }
+    ]
+});