From 27b5dd6d73e1159547c5189d3f48920c4c2b91b3 Mon Sep 17 00:00:00 2001
From: ANDO Yasushi <andyjpn@gmail.com>
Date: Fri, 8 Apr 2022 00:19:10 +0900
Subject: [PATCH 01/12] #1125 Fix parsing of unusual trailing expressions
 separated by whitespace

---
 NOTICE                                             |  1 +
 src/parser.ts                                      | 14 ++++++++++++--
 src/tokenizer.ts                                   | 12 ++++++++++++
 tests/parser/trailing-exps-separated-by-space.ts   |  8 ++++++++
 .../trailing-exps-separated-by-space.ts.fixture.ts | 11 +++++++++++
 5 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 tests/parser/trailing-exps-separated-by-space.ts
 create mode 100644 tests/parser/trailing-exps-separated-by-space.ts.fixture.ts

diff --git a/NOTICE b/NOTICE
index 3160d03559..81d66167db 100644
--- a/NOTICE
+++ b/NOTICE
@@ -44,6 +44,7 @@ under the licensing terms detailed in LICENSE:
 * Felipe Gasper <FGasper@users.noreply.github.com>
 * Congcong Cai <77575210+HerrCai0907@users.noreply.github.com>
 * mooooooi <emwings@outlook.com>
+* Yasushi Ando <andyjpn@gmail.com>
 
 Portions of this software are derived from third-party works licensed under
 the following terms:
diff --git a/src/parser.ts b/src/parser.ts
index b9dc2fc7b3..951eb4bad7 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -938,7 +938,12 @@ export class Parser extends DiagnosticEmitter {
     } while (tn.skip(Token.COMMA));
 
     var ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
-    tn.skip(Token.SEMICOLON);
+    if (!tn.skip(Token.SEMICOLON) && !isFor && !tn.hasNoExpressionInLine()) {
+      this.error(
+        DiagnosticCode.Unexpected_token,
+        tn.range()
+      );
+    }
     return ret;
   }
 
@@ -1115,7 +1120,12 @@ export class Parser extends DiagnosticEmitter {
     }
 
     var ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
-    tn.skip(Token.SEMICOLON);
+    if (!tn.skip(Token.SEMICOLON) && !tn.hasNoExpressionInLine()) {
+      this.error(
+        DiagnosticCode.Unexpected_token,
+        tn.range()
+      );
+    }
     return ret;
   }
 
diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index fab060fd5c..906d278605 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -1697,6 +1697,18 @@ export class Tokenizer extends DiagnosticEmitter {
     return this.readHexadecimalEscape(4, startIfTaggedTemplate);
   }
 
+  hasNoExpressionInLine(): bool {
+    let pos = this.pos;
+    const end = this.end;
+    do {
+      const c = this.source.text.charCodeAt(pos);
+      if (isLineBreak(c)) return true;
+      if (!isWhiteSpace(c)) break;
+      pos++;
+    } while (pos < end);
+    return pos === end;
+  }
+
   private readExtendedUnicodeEscape(startIfTaggedTemplate: i32 = -1): string {
     var start = this.pos;
     var value = this.readHexInteger();
diff --git a/tests/parser/trailing-exps-separated-by-space.ts b/tests/parser/trailing-exps-separated-by-space.ts
new file mode 100644
index 0000000000..a21531e9f3
--- /dev/null
+++ b/tests/parser/trailing-exps-separated-by-space.ts
@@ -0,0 +1,8 @@
+function add(y: i32): i32 {
+  let x = y 234;
+  return x + y;
+}
+
+function foo(): i32 {
+  return 123 456;
+}
\ No newline at end of file
diff --git a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
new file mode 100644
index 0000000000..dcac76f1ca
--- /dev/null
+++ b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
@@ -0,0 +1,11 @@
+function add(y: i32): i32 {
+  let x = y;
+  234;
+  return x + y;
+}
+function foo(): i32 {
+  return 123;
+  456;
+}
+// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(2,11+1)
+// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(7,10+3)

From 874b6ce1a1cde1c424ba7f14d373cfe44adce467 Mon Sep 17 00:00:00 2001
From: ANDO Yasushi <andyjpn@gmail.com>
Date: Fri, 8 Apr 2022 08:21:18 +0900
Subject: [PATCH 02/12] rename method

---
 src/parser.ts    | 4 ++--
 src/tokenizer.ts | 2 +-
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/parser.ts b/src/parser.ts
index 951eb4bad7..0dc2f3d5f7 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -938,7 +938,7 @@ export class Parser extends DiagnosticEmitter {
     } while (tn.skip(Token.COMMA));
 
     var ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.SEMICOLON) && !isFor && !tn.hasNoExpressionInLine()) {
+    if (!tn.skip(Token.SEMICOLON) && !isFor && !tn.hasNoMoreExpressionInLine()) {
       this.error(
         DiagnosticCode.Unexpected_token,
         tn.range()
@@ -1120,7 +1120,7 @@ export class Parser extends DiagnosticEmitter {
     }
 
     var ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.SEMICOLON) && !tn.hasNoExpressionInLine()) {
+    if (!tn.skip(Token.SEMICOLON) && !tn.hasNoMoreExpressionInLine()) {
       this.error(
         DiagnosticCode.Unexpected_token,
         tn.range()
diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index 906d278605..aeb11ddebd 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -1697,7 +1697,7 @@ export class Tokenizer extends DiagnosticEmitter {
     return this.readHexadecimalEscape(4, startIfTaggedTemplate);
   }
 
-  hasNoExpressionInLine(): bool {
+  hasNoMoreExpressionInLine(): bool {
     let pos = this.pos;
     const end = this.end;
     do {

From e53408eb273c0b17d813d49f965d43b4d2054cfc Mon Sep 17 00:00:00 2001
From: ANDO Yasushi <andyjpn@gmail.com>
Date: Mon, 11 Apr 2022 23:00:55 +0900
Subject: [PATCH 03/12] accept close brace & close paren

---
 src/tokenizer.ts                                      |  9 ++++-----
 tests/parser/trailing-exps-separated-by-space.ts      | 11 +++++++++--
 .../trailing-exps-separated-by-space.ts.fixture.ts    | 10 ++++++++--
 3 files changed, 21 insertions(+), 9 deletions(-)

diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index aeb11ddebd..8c7d508243 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -1699,14 +1699,13 @@ export class Tokenizer extends DiagnosticEmitter {
 
   hasNoMoreExpressionInLine(): bool {
     let pos = this.pos;
-    const end = this.end;
-    do {
+    while (pos < this.end) {
       const c = this.source.text.charCodeAt(pos);
-      if (isLineBreak(c)) return true;
+      if (isLineBreak(c) || c === CharCode.CLOSEBRACE || c === CharCode.CLOSEPAREN) return true;
       if (!isWhiteSpace(c)) break;
       pos++;
-    } while (pos < end);
-    return pos === end;
+    }
+    return pos === this.end;
   }
 
   private readExtendedUnicodeEscape(startIfTaggedTemplate: i32 = -1): string {
diff --git a/tests/parser/trailing-exps-separated-by-space.ts b/tests/parser/trailing-exps-separated-by-space.ts
index a21531e9f3..42aea19aad 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts
+++ b/tests/parser/trailing-exps-separated-by-space.ts
@@ -1,8 +1,15 @@
-function add(y: i32): i32 {
+function failLet(y: i32): i32 {
   let x = y 234;
   return x + y;
 }
 
-function foo(): i32 {
+function failReturn(): i32 {
   return 123 456;
+}
+
+function successCloseBrace(): i32 {
+  return 123 }
+
+function successCloseParen(): i32 {
+  return ( 123 )
 }
\ No newline at end of file
diff --git a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
index dcac76f1ca..f9fcaf376b 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
+++ b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
@@ -1,11 +1,17 @@
-function add(y: i32): i32 {
+function failLet(y: i32): i32 {
   let x = y;
   234;
   return x + y;
 }
-function foo(): i32 {
+function failReturn(): i32 {
   return 123;
   456;
 }
+function successCloseBrace(): i32 {
+  return 123;
+}
+function successCloseParen(): i32 {
+  return (123);
+}
 // ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(2,11+1)
 // ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(7,10+3)

From 64dba4f51420b7b85c3f7d86954338092fa6d6b3 Mon Sep 17 00:00:00 2001
From: ANDO Yasushi <andyjpn@gmail.com>
Date: Mon, 11 Apr 2022 23:16:05 +0900
Subject: [PATCH 04/12] rename to checkOffendingToken

---
 src/parser.ts    | 4 ++--
 src/tokenizer.ts | 6 +++---
 2 files changed, 5 insertions(+), 5 deletions(-)

diff --git a/src/parser.ts b/src/parser.ts
index 0dc2f3d5f7..5537aae881 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -938,7 +938,7 @@ export class Parser extends DiagnosticEmitter {
     } while (tn.skip(Token.COMMA));
 
     var ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.SEMICOLON) && !isFor && !tn.hasNoMoreExpressionInLine()) {
+    if (!tn.skip(Token.SEMICOLON) && !isFor && tn.checkOffendingToken()) {
       this.error(
         DiagnosticCode.Unexpected_token,
         tn.range()
@@ -1120,7 +1120,7 @@ export class Parser extends DiagnosticEmitter {
     }
 
     var ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.SEMICOLON) && !tn.hasNoMoreExpressionInLine()) {
+    if (!tn.skip(Token.SEMICOLON) && tn.checkOffendingToken()) {
       this.error(
         DiagnosticCode.Unexpected_token,
         tn.range()
diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index 8c7d508243..6d71948b90 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -1697,15 +1697,15 @@ export class Tokenizer extends DiagnosticEmitter {
     return this.readHexadecimalEscape(4, startIfTaggedTemplate);
   }
 
-  hasNoMoreExpressionInLine(): bool {
+  checkOffendingToken(): bool {
     let pos = this.pos;
     while (pos < this.end) {
       const c = this.source.text.charCodeAt(pos);
-      if (isLineBreak(c) || c === CharCode.CLOSEBRACE || c === CharCode.CLOSEPAREN) return true;
+      if (isLineBreak(c) || c === CharCode.CLOSEBRACE || c === CharCode.CLOSEPAREN) return false;
       if (!isWhiteSpace(c)) break;
       pos++;
     }
-    return pos === this.end;
+    return pos !== this.end;
   }
 
   private readExtendedUnicodeEscape(startIfTaggedTemplate: i32 = -1): string {

From 66216be880abf5d1d1700b62e42077f7fce957a6 Mon Sep 17 00:00:00 2001
From: ANDO Yasushi <andyjpn@gmail.com>
Date: Tue, 12 Apr 2022 00:12:35 +0900
Subject: [PATCH 05/12] handle throw statement

---
 src/parser.ts                                 | 28 ++++++++++---------
 .../trailing-exps-separated-by-space.ts       |  4 +++
 ...ling-exps-separated-by-space.ts.fixture.ts |  5 ++++
 3 files changed, 24 insertions(+), 13 deletions(-)

diff --git a/src/parser.ts b/src/parser.ts
index 5537aae881..568cbc0b7c 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -938,12 +938,7 @@ export class Parser extends DiagnosticEmitter {
     } while (tn.skip(Token.COMMA));
 
     var ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.SEMICOLON) && !isFor && tn.checkOffendingToken()) {
-      this.error(
-        DiagnosticCode.Unexpected_token,
-        tn.range()
-      );
-    }
+    this.checkRuleCompleted(tn, isFor);
     return ret;
   }
 
@@ -1120,12 +1115,7 @@ export class Parser extends DiagnosticEmitter {
     }
 
     var ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.SEMICOLON) && tn.checkOffendingToken()) {
-      this.error(
-        DiagnosticCode.Unexpected_token,
-        tn.range()
-      );
-    }
+    this.checkRuleCompleted(tn);
     return ret;
   }
 
@@ -3386,7 +3376,7 @@ export class Parser extends DiagnosticEmitter {
     var expression = this.parseExpression(tn);
     if (!expression) return null;
     var ret = Node.createThrowStatement(expression, tn.range(startPos, tn.pos));
-    tn.skip(Token.SEMICOLON);
+    this.checkRuleCompleted(tn);
     return ret;
   }
 
@@ -4321,6 +4311,18 @@ export class Parser extends DiagnosticEmitter {
     return expr;
   }
 
+  private checkRuleCompleted(
+    tn: Tokenizer,
+    isFor: bool = false
+  ) {
+    if (!tn.skip(Token.SEMICOLON) && !isFor && tn.checkOffendingToken()) {
+      this.error(
+        DiagnosticCode.Unexpected_token,
+        tn.range()
+      );
+    }
+  }
+
   /** Skips over a statement on errors in an attempt to reduce unnecessary diagnostic noise. */
   skipStatement(tn: Tokenizer): void {
     tn.peek(true);
diff --git a/tests/parser/trailing-exps-separated-by-space.ts b/tests/parser/trailing-exps-separated-by-space.ts
index 42aea19aad..3bef368afb 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts
+++ b/tests/parser/trailing-exps-separated-by-space.ts
@@ -7,6 +7,10 @@ function failReturn(): i32 {
   return 123 456;
 }
 
+function failThrow(): i32 {
+  throw 123 456;
+}
+
 function successCloseBrace(): i32 {
   return 123 }
 
diff --git a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
index f9fcaf376b..4ce4a6dbfd 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
+++ b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
@@ -7,6 +7,10 @@ function failReturn(): i32 {
   return 123;
   456;
 }
+function failThrow(): i32 {
+  throw 123;
+  456;
+}
 function successCloseBrace(): i32 {
   return 123;
 }
@@ -15,3 +19,4 @@ function successCloseParen(): i32 {
 }
 // ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(2,11+1)
 // ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(7,10+3)
+// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(11,9+3)

From c79762a7f1cb6c9703d3a47e358ef8d3170111ca Mon Sep 17 00:00:00 2001
From: ANDO Yasushi <andyjpn@gmail.com>
Date: Tue, 12 Apr 2022 00:56:15 +0900
Subject: [PATCH 06/12] add type

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

diff --git a/src/parser.ts b/src/parser.ts
index 568cbc0b7c..8c69ae4861 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -4314,7 +4314,7 @@ export class Parser extends DiagnosticEmitter {
   private checkRuleCompleted(
     tn: Tokenizer,
     isFor: bool = false
-  ) {
+  ): void {
     if (!tn.skip(Token.SEMICOLON) && !isFor && tn.checkOffendingToken()) {
       this.error(
         DiagnosticCode.Unexpected_token,

From 024ceac0fc278a4c08c7bc459dcd2b7e37aeb33b Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sun, 8 Jan 2023 12:54:13 +0100
Subject: [PATCH 07/12] fix

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

diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index 94ed40ecff..e750f7732b 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -1714,7 +1714,7 @@ export class Tokenizer extends DiagnosticEmitter {
     let pos = this.pos;
     while (pos < this.end) {
       const c = this.source.text.charCodeAt(pos);
-      if (isLineBreak(c) || c === CharCode.CLOSEBRACE || c === CharCode.CLOSEPAREN) return false;
+      if (isLineBreak(c) || c === CharCode.CloseBrace || c === CharCode.CloseParen) return false;
       if (!isWhiteSpace(c)) break;
       pos++;
     }

From 07a70d5a79845309c1d34895b11c0f5fc033827e Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sun, 8 Jan 2023 12:55:22 +0100
Subject: [PATCH 08/12] var -> let

---
 src/parser.ts | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/parser.ts b/src/parser.ts
index 85a3ecec00..efad16a5ff 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -938,7 +938,7 @@ export class Parser extends DiagnosticEmitter {
       declarations.push(declaration);
     } while (tn.skip(Token.Comma));
 
-    var ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
+    let  ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
     this.checkRuleCompleted(tn, isFor);
     return ret;
   }
@@ -1121,7 +1121,7 @@ export class Parser extends DiagnosticEmitter {
       if (!(expr = this.parseExpression(tn))) return null;
     }
 
-    var ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
+    let ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
     this.checkRuleCompleted(tn);
     return ret;
   }
@@ -3416,7 +3416,7 @@ export class Parser extends DiagnosticEmitter {
     let startPos = tn.tokenPos;
     let expression = this.parseExpression(tn);
     if (!expression) return null;
-    var ret = Node.createThrowStatement(expression, tn.range(startPos, tn.pos));
+    let ret = Node.createThrowStatement(expression, tn.range(startPos, tn.pos));
     this.checkRuleCompleted(tn);
     return ret;
   }

From 218ec9a4863bf50d24cd8c68b33c0c7dfc24b2af Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sun, 8 Jan 2023 12:56:08 +0100
Subject: [PATCH 09/12] whitespace

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

diff --git a/src/parser.ts b/src/parser.ts
index efad16a5ff..434ad9791f 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -938,7 +938,7 @@ export class Parser extends DiagnosticEmitter {
       declarations.push(declaration);
     } while (tn.skip(Token.Comma));
 
-    let  ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
+    let ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
     this.checkRuleCompleted(tn, isFor);
     return ret;
   }

From 74f4b35d5647926419290807d4faad3960e2b056 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sun, 8 Jan 2023 13:43:51 +0100
Subject: [PATCH 10/12] simplify

---
 src/parser.ts | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/src/parser.ts b/src/parser.ts
index 434ad9791f..b9a4c5cf42 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -939,7 +939,7 @@ export class Parser extends DiagnosticEmitter {
     } while (tn.skip(Token.Comma));
 
     let ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
-    this.checkRuleCompleted(tn, isFor);
+    if (!tn.skip(Token.Semicolon) && !isFor) this.checkRuleCompleted(tn, isFor);
     return ret;
   }
 
@@ -1122,7 +1122,7 @@ export class Parser extends DiagnosticEmitter {
     }
 
     let ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
-    this.checkRuleCompleted(tn);
+    if (!tn.skip(Token.Semicolon)) this.checkRuleCompleted(tn);
     return ret;
   }
 
@@ -3417,7 +3417,7 @@ export class Parser extends DiagnosticEmitter {
     let expression = this.parseExpression(tn);
     if (!expression) return null;
     let ret = Node.createThrowStatement(expression, tn.range(startPos, tn.pos));
-    this.checkRuleCompleted(tn);
+    if (!tn.skip(Token.Semicolon)) this.checkRuleCompleted(tn);
     return ret;
   }
 
@@ -4402,10 +4402,9 @@ export class Parser extends DiagnosticEmitter {
   }
 
   private checkRuleCompleted(
-    tn: Tokenizer,
-    isFor: bool = false
+    tn: Tokenizer
   ): void {
-    if (!tn.skip(Token.Semicolon) && !isFor && tn.checkOffendingToken()) {
+    if (tn.checkOffendingToken()) {
       this.error(
         DiagnosticCode.Unexpected_token,
         tn.range()

From 3ec977e730649005bf84462222019aa15053ea99 Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sun, 8 Jan 2023 14:28:12 +0100
Subject: [PATCH 11/12] refactor

---
 src/parser.ts                                 | 23 +++++-----
 src/tokenizer.ts                              | 11 -----
 ...ling-exps-separated-by-space.ts.fixture.ts | 44 +++++++++----------
 3 files changed, 34 insertions(+), 44 deletions(-)

diff --git a/src/parser.ts b/src/parser.ts
index b9a4c5cf42..27f0af6320 100644
--- a/src/parser.ts
+++ b/src/parser.ts
@@ -939,7 +939,7 @@ export class Parser extends DiagnosticEmitter {
     } while (tn.skip(Token.Comma));
 
     let ret = Node.createVariableStatement(decorators, declarations, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.Semicolon) && !isFor) this.checkRuleCompleted(tn, isFor);
+    if (!tn.skip(Token.Semicolon) && !isFor) this.checkASI(tn);
     return ret;
   }
 
@@ -1122,7 +1122,7 @@ export class Parser extends DiagnosticEmitter {
     }
 
     let ret = Node.createReturnStatement(expr, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.Semicolon)) this.checkRuleCompleted(tn);
+    if (!tn.skip(Token.Semicolon)) this.checkASI(tn);
     return ret;
   }
 
@@ -3009,7 +3009,7 @@ export class Parser extends DiagnosticEmitter {
       }
     }
     let ret = Node.createBlockStatement(statements, tn.range(startPos, tn.pos));
-    tn.skip(Token.Semicolon);
+    if (topLevel) tn.skip(Token.Semicolon);
     return ret;
   }
 
@@ -3417,7 +3417,7 @@ export class Parser extends DiagnosticEmitter {
     let expression = this.parseExpression(tn);
     if (!expression) return null;
     let ret = Node.createThrowStatement(expression, tn.range(startPos, tn.pos));
-    if (!tn.skip(Token.Semicolon)) this.checkRuleCompleted(tn);
+    if (!tn.skip(Token.Semicolon)) this.checkASI(tn);
     return ret;
   }
 
@@ -4401,15 +4401,16 @@ export class Parser extends DiagnosticEmitter {
     return expr;
   }
 
-  private checkRuleCompleted(
+  private checkASI(
     tn: Tokenizer
   ): void {
-    if (tn.checkOffendingToken()) {
-      this.error(
-        DiagnosticCode.Unexpected_token,
-        tn.range()
-      );
-    }
+    // see: https://tc39.es/ecma262/#sec-automatic-semicolon-insertion
+    let token = tn.peek(true);
+    if (tn.nextTokenOnNewLine || token == Token.EndOfFile || token == Token.CloseBrace) return;
+    this.error(
+      DiagnosticCode.Unexpected_token,
+      tn.range(tn.nextTokenPos)
+    );
   }
 
   /** Skips over a statement on errors in an attempt to reduce unnecessary diagnostic noise. */
diff --git a/src/tokenizer.ts b/src/tokenizer.ts
index e750f7732b..767ee03489 100644
--- a/src/tokenizer.ts
+++ b/src/tokenizer.ts
@@ -1710,17 +1710,6 @@ export class Tokenizer extends DiagnosticEmitter {
     return this.readHexadecimalEscape(4, startIfTaggedTemplate);
   }
 
-  checkOffendingToken(): bool {
-    let pos = this.pos;
-    while (pos < this.end) {
-      const c = this.source.text.charCodeAt(pos);
-      if (isLineBreak(c) || c === CharCode.CloseBrace || c === CharCode.CloseParen) return false;
-      if (!isWhiteSpace(c)) break;
-      pos++;
-    }
-    return pos !== this.end;
-  }
-
   private readExtendedUnicodeEscape(startIfTaggedTemplate: i32 = -1): string {
     let start = this.pos;
     let value = this.readHexInteger();
diff --git a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
index 4ce4a6dbfd..3001745422 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
+++ b/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
@@ -1,22 +1,22 @@
-function failLet(y: i32): i32 {
-  let x = y;
-  234;
-  return x + y;
-}
-function failReturn(): i32 {
-  return 123;
-  456;
-}
-function failThrow(): i32 {
-  throw 123;
-  456;
-}
-function successCloseBrace(): i32 {
-  return 123;
-}
-function successCloseParen(): i32 {
-  return (123);
-}
-// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(2,11+1)
-// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(7,10+3)
-// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(11,9+3)
+function failLet(y: i32): i32 {
+  let x = y;
+  234;
+  return x + y;
+}
+function failReturn(): i32 {
+  return 123;
+  456;
+}
+function failThrow(): i32 {
+  throw 123;
+  456;
+}
+function successCloseBrace(): i32 {
+  return 123;
+}
+function successCloseParen(): i32 {
+  return (123);
+}
+// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(2,13+0)
+// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(7,14+0)
+// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(11,13+0)

From 3855542b75f31f870faf47bb8c941a5623ef72aa Mon Sep 17 00:00:00 2001
From: dcode <dcode@dcode.io>
Date: Sun, 8 Jan 2023 14:41:21 +0100
Subject: [PATCH 12/12] rename test case

---
 ...ling-exps-separated-by-space.ts => asi.ts} | 36 +++++++++----------
 ...-space.ts.fixture.ts => asi.ts.fixture.ts} |  6 ++--
 2 files changed, 21 insertions(+), 21 deletions(-)
 rename tests/parser/{trailing-exps-separated-by-space.ts => asi.ts} (93%)
 rename tests/parser/{trailing-exps-separated-by-space.ts.fixture.ts => asi.ts.fixture.ts} (52%)

diff --git a/tests/parser/trailing-exps-separated-by-space.ts b/tests/parser/asi.ts
similarity index 93%
rename from tests/parser/trailing-exps-separated-by-space.ts
rename to tests/parser/asi.ts
index 3bef368afb..542d063520 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts
+++ b/tests/parser/asi.ts
@@ -1,19 +1,19 @@
-function failLet(y: i32): i32 {
-  let x = y 234;
-  return x + y;
-}
-
-function failReturn(): i32 {
-  return 123 456;
-}
-
-function failThrow(): i32 {
-  throw 123 456;
-}
-
-function successCloseBrace(): i32 {
-  return 123 }
-
-function successCloseParen(): i32 {
-  return ( 123 )
+function failLet(y: i32): i32 {
+  let x = y 234;
+  return x + y;
+}
+
+function failReturn(): i32 {
+  return 123 456;
+}
+
+function failThrow(): i32 {
+  throw 123 456;
+}
+
+function successCloseBrace(): i32 {
+  return 123 }
+
+function successCloseParen(): i32 {
+  return ( 123 )
 }
\ No newline at end of file
diff --git a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts b/tests/parser/asi.ts.fixture.ts
similarity index 52%
rename from tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
rename to tests/parser/asi.ts.fixture.ts
index 3001745422..d6d8e567b8 100644
--- a/tests/parser/trailing-exps-separated-by-space.ts.fixture.ts
+++ b/tests/parser/asi.ts.fixture.ts
@@ -17,6 +17,6 @@ function successCloseBrace(): i32 {
 function successCloseParen(): i32 {
   return (123);
 }
-// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(2,13+0)
-// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(7,14+0)
-// ERROR 1012: "Unexpected token." in trailing-exps-separated-by-space.ts(11,13+0)
+// ERROR 1012: "Unexpected token." in asi.ts(2,13+0)
+// ERROR 1012: "Unexpected token." in asi.ts(7,14+0)
+// ERROR 1012: "Unexpected token." in asi.ts(11,13+0)