From 993e5cadaf7747947f6aa9199d90f6f03749e67b Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Thu, 29 Aug 2024 22:59:41 +0300
Subject: [PATCH 1/2] fix(59779): eliminate redundant semicolons before
 existing semicolons

---
 src/services/formatting/rules.ts              |  7 +++
 .../fourslash/formatRemoveSemicolons1.ts      |  4 +-
 .../fourslash/formatRemoveSemicolons4.ts      | 48 +++++++++++++++++++
 3 files changed, 57 insertions(+), 2 deletions(-)
 create mode 100644 tests/cases/fourslash/formatRemoveSemicolons4.ts

diff --git a/src/services/formatting/rules.ts b/src/services/formatting/rules.ts
index 806dc6003f510..45d80841d1894 100644
--- a/src/services/formatting/rules.ts
+++ b/src/services/formatting/rules.ts
@@ -933,6 +933,13 @@ function isSemicolonDeletionContext(context: FormattingContext): boolean {
             || nextTokenKind === SyntaxKind.EndOfFileToken;
     }
 
+    if (
+        nextTokenKind === SyntaxKind.SemicolonToken &&
+        context.currentTokenSpan.kind === SyntaxKind.SemicolonToken
+    ) {
+        return true;
+    }
+
     if (
         nextTokenKind === SyntaxKind.SemicolonClassElement ||
         nextTokenKind === SyntaxKind.SemicolonToken
diff --git a/tests/cases/fourslash/formatRemoveSemicolons1.ts b/tests/cases/fourslash/formatRemoveSemicolons1.ts
index b80ecee7edb2d..39735fe0a8d93 100644
--- a/tests/cases/fourslash/formatRemoveSemicolons1.ts
+++ b/tests/cases/fourslash/formatRemoveSemicolons1.ts
@@ -51,7 +51,7 @@ class C {
     ["p"]
     zero: void
     ["one"] = {};
-    ["two"];
+    ["two"]
     ;
 }
 a;
@@ -59,7 +59,7 @@ a;
 b;
 (3)
 4;
-/ regex /;
+/ regex /
 ;
 [];
 /** blah */[0]
diff --git a/tests/cases/fourslash/formatRemoveSemicolons4.ts b/tests/cases/fourslash/formatRemoveSemicolons4.ts
new file mode 100644
index 0000000000000..299efa837a74c
--- /dev/null
+++ b/tests/cases/fourslash/formatRemoveSemicolons4.ts
@@ -0,0 +1,48 @@
+/// <reference path="fourslash.ts" />
+
+////declare const opt: number | undefined;
+////
+////const a = 1;
+////const b = 2;
+////;[1, 2, 3]
+////
+////const c = opt ? 1 : 2;
+////const d = opt ? 1 : 2;
+////;[1, 2, 3]
+////
+////const e = opt ?? 1;
+////const f = opt ?? 1;
+////;[1, 2, 3]
+////
+////type a = 1;
+////type b = 2;
+////;[1, 2, 3]
+////
+////type c = typeof opt extends 1 ? 1 : 2;
+////type d = typeof opt extends 1 ? 1 : 2;
+////;[1, 2, 3]
+
+format.setFormatOptions({ ...format.copyFormatOptions(), semicolons: ts.SemicolonPreference.Remove });
+format.document();
+verify.currentFileContentIs(
+`declare const opt: number | undefined
+
+const a = 1
+const b = 2
+;[1, 2, 3]
+
+const c = opt ? 1 : 2
+const d = opt ? 1 : 2
+;[1, 2, 3]
+
+const e = opt ?? 1
+const f = opt ?? 1
+;[1, 2, 3]
+
+type a = 1
+type b = 2
+;[1, 2, 3]
+
+type c = typeof opt extends 1 ? 1 : 2
+type d = typeof opt extends 1 ? 1 : 2
+;[1, 2, 3]`);

From b7bddd8e3062428aa51c1d4c9c2c3c58a1ab25f4 Mon Sep 17 00:00:00 2001
From: Oleksandr T <oleksandr.tarasiuk@outlook.com>
Date: Thu, 29 Aug 2024 23:36:07 +0300
Subject: [PATCH 2/2] fix formatting

---
 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 5d4be5660aabe..614a958d618d4 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -22056,7 +22056,7 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             const [sourceType, targetType] = getTypeNamesForErrorDisplay(source, target);
             let generalizedSource = source;
             let generalizedSourceType = sourceType;
-            
+
             // Don't generalize on 'never' - we really want the original type
             // to be displayed for use-cases like 'assertNever'.
             if (!(target.flags & TypeFlags.Never) && isLiteralType(source) && !typeCouldHaveTopLevelSingletonTypes(target)) {