From 0fa4c6e33e87b05845d4029111b6ee5c12ffdb0b Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <kirk.waiblinger@gmail.com>
Date: Tue, 22 Oct 2024 12:31:47 -0600
Subject: [PATCH 1/3] fix up always-truthy check for 0n and support negative
 numbers

---
 src/compiler/checker.ts                       | 27 +++++++-
 ...alOperatorConditionIsNumberType.errors.txt |  8 ++-
 .../reference/predicateSemantics.errors.txt   | 64 ++++++++++++++++++-
 .../baselines/reference/predicateSemantics.js | 40 +++++++++++-
 .../reference/predicateSemantics.symbols      | 21 ++++++
 .../reference/predicateSemantics.types        | 54 ++++++++++++++++
 tests/cases/compiler/predicateSemantics.ts    | 23 ++++++-
 7 files changed, 231 insertions(+), 6 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 295b8b3c2578a..1cbc5d4a684b2 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -44504,9 +44504,34 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     return PredicateSemantics.Sometimes;
                 }
                 return PredicateSemantics.Always;
+            case SyntaxKind.BigIntLiteral:
+                if ((node as BigIntLiteral).text === "0n") {
+                    // unlike `while(0)`, `while (0n)` is not idiomatic.
+                    return PredicateSemantics.Never;
+                }
+                return PredicateSemantics.Always;
+            // handle negative numbers
+            case SyntaxKind.PrefixUnaryExpression:
+                const prefixUnaryExpression = node as PrefixUnaryExpression;
+                if (prefixUnaryExpression.operator === SyntaxKind.MinusToken) {
+                    const operand = prefixUnaryExpression.operand;
+                    if (operand.kind === SyntaxKind.NumericLiteral) {
+                        if ((operand as NumericLiteral).text === "0") {
+                            return PredicateSemantics.Never
+                        } else {
+                            return PredicateSemantics.Always
+                        }
+                    } else if (operand.kind === SyntaxKind.BigIntLiteral) {
+                        if ((operand as BigIntLiteral).text === "0n") {
+                            return PredicateSemantics.Never
+                        } else {
+                            return PredicateSemantics.Always
+                        }
+                    }
+                }
+                return PredicateSemantics.Sometimes
             case SyntaxKind.ArrayLiteralExpression:
             case SyntaxKind.ArrowFunction:
-            case SyntaxKind.BigIntLiteral:
             case SyntaxKind.ClassExpression:
             case SyntaxKind.FunctionExpression:
             case SyntaxKind.JsxElement:
diff --git a/tests/baselines/reference/conditionalOperatorConditionIsNumberType.errors.txt b/tests/baselines/reference/conditionalOperatorConditionIsNumberType.errors.txt
index dfc26d8324850..fdbb1eefa6fc4 100644
--- a/tests/baselines/reference/conditionalOperatorConditionIsNumberType.errors.txt
+++ b/tests/baselines/reference/conditionalOperatorConditionIsNumberType.errors.txt
@@ -1,12 +1,14 @@
 conditionalOperatorConditionIsNumberType.ts(27,1): error TS2872: This kind of expression is always truthy.
+conditionalOperatorConditionIsNumberType.ts(28,1): error TS2872: This kind of expression is always truthy.
 conditionalOperatorConditionIsNumberType.ts(29,1): error TS2872: This kind of expression is always truthy.
 conditionalOperatorConditionIsNumberType.ts(30,1): error TS2872: This kind of expression is always truthy.
 conditionalOperatorConditionIsNumberType.ts(53,23): error TS2872: This kind of expression is always truthy.
+conditionalOperatorConditionIsNumberType.ts(54,23): error TS2872: This kind of expression is always truthy.
 conditionalOperatorConditionIsNumberType.ts(55,23): error TS2872: This kind of expression is always truthy.
 conditionalOperatorConditionIsNumberType.ts(56,32): error TS2872: This kind of expression is always truthy.
 
 
-==== conditionalOperatorConditionIsNumberType.ts (6 errors) ====
+==== conditionalOperatorConditionIsNumberType.ts (8 errors) ====
     //Cond ? Expr1 : Expr2,  Cond is of number type, Expr1 and Expr2 have the same type
     var condNumber: number;
     
@@ -37,6 +39,8 @@ conditionalOperatorConditionIsNumberType.ts(56,32): error TS2872: This kind of e
     ~~~~~~~~~~~
 !!! error TS2872: This kind of expression is always truthy.
     - 10000000000000 ? exprString1 : exprString2;
+    ~~~~~~~~~~~~~~~~
+!!! error TS2872: This kind of expression is always truthy.
     1000000000000 ? exprIsObject1 : exprIsObject2;
     ~~~~~~~~~~~~~
 !!! error TS2872: This kind of expression is always truthy.
@@ -69,6 +73,8 @@ conditionalOperatorConditionIsNumberType.ts(56,32): error TS2872: This kind of e
                           ~~~~~~~~~~~
 !!! error TS2872: This kind of expression is always truthy.
     var resultIsString2 = - 10000000000000 ? exprString1 : exprString2;
+                          ~~~~~~~~~~~~~~~~
+!!! error TS2872: This kind of expression is always truthy.
     var resultIsObject2 = 1000000000000 ? exprIsObject1 : exprIsObject2;
                           ~~~~~~~~~~~~~
 !!! error TS2872: This kind of expression is always truthy.
diff --git a/tests/baselines/reference/predicateSemantics.errors.txt b/tests/baselines/reference/predicateSemantics.errors.txt
index 14251121358c4..4c1e055cc9ecc 100644
--- a/tests/baselines/reference/predicateSemantics.errors.txt
+++ b/tests/baselines/reference/predicateSemantics.errors.txt
@@ -9,9 +9,22 @@ predicateSemantics.ts(33,8): error TS2872: This kind of expression is always tru
 predicateSemantics.ts(34,11): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(35,8): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(36,8): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(47,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(47,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(50,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(50,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(52,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(52,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(56,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(58,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(60,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(60,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(62,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(62,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(65,6): error TS2304: Cannot find name 'identifier'.
 
 
-==== predicateSemantics.ts (11 errors) ====
+==== predicateSemantics.ts (24 errors) ====
     declare let cond: any;
     
     // OK: One or other operand is possibly nullish
@@ -77,4 +90,51 @@ predicateSemantics.ts(36,8): error TS2872: This kind of expression is always tru
     function foo(this: Object | undefined) {
         // Should be OK
         return this ?? 0;
-    }
\ No newline at end of file
+    }
+    
+    // Not OK; always truthy.
+    if (1n) { }
+        ~~
+!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
+        ~~
+!!! error TS2872: This kind of expression is always truthy.
+    
+    // Not OK; always falsy.
+    if (0n) { } 
+        ~~
+!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
+        ~~
+!!! error TS2873: This kind of expression is always falsy.
+    // Not OK; always falsy.
+    if (-0n) { }
+        ~~~
+!!! error TS2873: This kind of expression is always falsy.
+         ~~
+!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
+    
+    // negative numbers
+    // not OK - truthy
+    if (-1.2) { }
+        ~~~~
+!!! error TS2872: This kind of expression is always truthy.
+    // not OK - falsy
+    if (-0.0000){}
+        ~~~~~~~
+!!! error TS2873: This kind of expression is always falsy.
+    // not OK - falsy
+    if (-0n){}
+        ~~~
+!!! error TS2873: This kind of expression is always falsy.
+         ~~
+!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
+    // not OK - truthy
+    if (-13n){}
+        ~~~~
+!!! error TS2872: This kind of expression is always truthy.
+         ~~~
+!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
+    
+    // OK
+    if (-identifier) {}
+         ~~~~~~~~~~
+!!! error TS2304: Cannot find name 'identifier'.
\ No newline at end of file
diff --git a/tests/baselines/reference/predicateSemantics.js b/tests/baselines/reference/predicateSemantics.js
index eb0b66516b62c..901f61eb2bb91 100644
--- a/tests/baselines/reference/predicateSemantics.js
+++ b/tests/baselines/reference/predicateSemantics.js
@@ -44,7 +44,28 @@ console.log((cond || undefined) && 1 / cond);
 function foo(this: Object | undefined) {
     // Should be OK
     return this ?? 0;
-}
+}
+
+// Not OK; always truthy.
+if (1n) { }
+
+// Not OK; always falsy.
+if (0n) { } 
+// Not OK; always falsy.
+if (-0n) { }
+
+// negative numbers
+// not OK - truthy
+if (-1.2) { }
+// not OK - falsy
+if (-0.0000){}
+// not OK - falsy
+if (-0n){}
+// not OK - truthy
+if (-13n){}
+
+// OK
+if (-identifier) {}
 
 //// [predicateSemantics.js]
 var _a, _b, _c, _d, _e, _f;
@@ -88,3 +109,20 @@ function foo() {
     // Should be OK
     return this !== null && this !== void 0 ? this : 0;
 }
+// Not OK; always truthy.
+if (1n) { }
+// Not OK; always falsy.
+if (0n) { }
+// Not OK; always falsy.
+if (-0n) { }
+// negative numbers
+// not OK - truthy
+if (-1.2) { }
+// not OK - falsy
+if (-0.0000) { }
+// not OK - falsy
+if (-0n) { }
+// not OK - truthy
+if (-13n) { }
+// OK
+if (-identifier) { }
diff --git a/tests/baselines/reference/predicateSemantics.symbols b/tests/baselines/reference/predicateSemantics.symbols
index 790e965f988cc..0e82ab24238a2 100644
--- a/tests/baselines/reference/predicateSemantics.symbols
+++ b/tests/baselines/reference/predicateSemantics.symbols
@@ -79,3 +79,24 @@ function foo(this: Object | undefined) {
     return this ?? 0;
 >this : Symbol(this, Decl(predicateSemantics.ts, 40, 13))
 }
+
+// Not OK; always truthy.
+if (1n) { }
+
+// Not OK; always falsy.
+if (0n) { } 
+// Not OK; always falsy.
+if (-0n) { }
+
+// negative numbers
+// not OK - truthy
+if (-1.2) { }
+// not OK - falsy
+if (-0.0000){}
+// not OK - falsy
+if (-0n){}
+// not OK - truthy
+if (-13n){}
+
+// OK
+if (-identifier) {}
diff --git a/tests/baselines/reference/predicateSemantics.types b/tests/baselines/reference/predicateSemantics.types
index 3d3eba6683e25..1b131c4a940cd 100644
--- a/tests/baselines/reference/predicateSemantics.types
+++ b/tests/baselines/reference/predicateSemantics.types
@@ -234,3 +234,57 @@ function foo(this: Object | undefined) {
 >0 : 0
 >  : ^
 }
+
+// Not OK; always truthy.
+if (1n) { }
+>1n : 1n
+>   : ^^
+
+// Not OK; always falsy.
+if (0n) { } 
+>0n : 0n
+>   : ^^
+
+// Not OK; always falsy.
+if (-0n) { }
+>-0n : 0n
+>    : ^^
+>0n : 0n
+>   : ^^
+
+// negative numbers
+// not OK - truthy
+if (-1.2) { }
+>-1.2 : -1.2
+>     : ^^^^
+>1.2 : 1.2
+>    : ^^^
+
+// not OK - falsy
+if (-0.0000){}
+>-0.0000 : 0
+>        : ^
+>0.0000 : 0
+>       : ^
+
+// not OK - falsy
+if (-0n){}
+>-0n : 0n
+>    : ^^
+>0n : 0n
+>   : ^^
+
+// not OK - truthy
+if (-13n){}
+>-13n : -13n
+>     : ^^^^
+>13n : 13n
+>    : ^^^
+
+// OK
+if (-identifier) {}
+>-identifier : number
+>            : ^^^^^^
+>identifier : any
+>           : ^^^
+
diff --git a/tests/cases/compiler/predicateSemantics.ts b/tests/cases/compiler/predicateSemantics.ts
index d6e12b297b25b..c8d7b461d8f61 100644
--- a/tests/cases/compiler/predicateSemantics.ts
+++ b/tests/cases/compiler/predicateSemantics.ts
@@ -41,4 +41,25 @@ console.log((cond || undefined) && 1 / cond);
 function foo(this: Object | undefined) {
     // Should be OK
     return this ?? 0;
-}
\ No newline at end of file
+}
+
+// Not OK; always truthy.
+if (1n) { }
+
+// Not OK; always falsy.
+if (0n) { } 
+// Not OK; always falsy.
+if (-0n) { }
+
+// negative numbers
+// not OK - truthy
+if (-1.2) { }
+// not OK - falsy
+if (-0.0000){}
+// not OK - falsy
+if (-0n){}
+// not OK - truthy
+if (-13n){}
+
+// OK
+if (-identifier) {}
\ No newline at end of file

From 95934eecb45370517f6cd8dbe62b0a34d3ad2d4e Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <kirk.waiblinger@gmail.com>
Date: Tue, 22 Oct 2024 12:59:32 -0600
Subject: [PATCH 2/3] positive numbers too, hehe

---
 src/compiler/checker.ts                       | 33 ++++++++--------
 .../reference/predicateSemantics.errors.txt   | 38 ++++++++++++-------
 .../baselines/reference/predicateSemantics.js |  7 ++++
 .../reference/predicateSemantics.symbols      |  4 ++
 .../reference/predicateSemantics.types        | 13 +++++++
 tests/cases/compiler/predicateSemantics.ts    |  4 ++
 6 files changed, 69 insertions(+), 30 deletions(-)

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index 1cbc5d4a684b2..e605d1ff77689 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -44510,26 +44510,27 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
                     return PredicateSemantics.Never;
                 }
                 return PredicateSemantics.Always;
-            // handle negative numbers
+            // handle +123, -123, -123n, etc.
             case SyntaxKind.PrefixUnaryExpression:
                 const prefixUnaryExpression = node as PrefixUnaryExpression;
-                if (prefixUnaryExpression.operator === SyntaxKind.MinusToken) {
-                    const operand = prefixUnaryExpression.operand;
-                    if (operand.kind === SyntaxKind.NumericLiteral) {
-                        if ((operand as NumericLiteral).text === "0") {
-                            return PredicateSemantics.Never
-                        } else {
-                            return PredicateSemantics.Always
-                        }
-                    } else if (operand.kind === SyntaxKind.BigIntLiteral) {
-                        if ((operand as BigIntLiteral).text === "0n") {
-                            return PredicateSemantics.Never
-                        } else {
-                            return PredicateSemantics.Always
-                        }
+                const { operator, operand } = prefixUnaryExpression;
+                if (operand.kind === SyntaxKind.NumericLiteral && (operator === SyntaxKind.MinusToken || operator === SyntaxKind.PlusToken)) {
+                    if ((operand as NumericLiteral).text === "0") {
+                        return PredicateSemantics.Never;
+                    }
+                    else {
+                        return PredicateSemantics.Always;
                     }
                 }
-                return PredicateSemantics.Sometimes
+                else if (operand.kind === SyntaxKind.BigIntLiteral && operator === SyntaxKind.MinusToken) {
+                    if ((operand as BigIntLiteral).text === "0n") {
+                        return PredicateSemantics.Never;
+                    }
+                    else {
+                        return PredicateSemantics.Always;
+                    }
+                }
+                return PredicateSemantics.Sometimes;
             case SyntaxKind.ArrayLiteralExpression:
             case SyntaxKind.ArrowFunction:
             case SyntaxKind.ClassExpression:
diff --git a/tests/baselines/reference/predicateSemantics.errors.txt b/tests/baselines/reference/predicateSemantics.errors.txt
index 4c1e055cc9ecc..02a2fd93dae7c 100644
--- a/tests/baselines/reference/predicateSemantics.errors.txt
+++ b/tests/baselines/reference/predicateSemantics.errors.txt
@@ -9,22 +9,24 @@ predicateSemantics.ts(33,8): error TS2872: This kind of expression is always tru
 predicateSemantics.ts(34,11): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(35,8): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(36,8): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(47,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(47,5): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(50,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(50,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(52,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(52,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(56,5): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(58,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(60,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(60,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(62,5): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(62,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(65,6): error TS2304: Cannot find name 'identifier'.
+predicateSemantics.ts(47,8): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(48,8): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(51,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(51,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(54,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(54,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(56,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(56,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(60,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(62,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(64,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(64,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(66,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(66,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
+predicateSemantics.ts(69,6): error TS2304: Cannot find name 'identifier'.
 
 
-==== predicateSemantics.ts (24 errors) ====
+==== predicateSemantics.ts (26 errors) ====
     declare let cond: any;
     
     // OK: One or other operand is possibly nullish
@@ -92,6 +94,14 @@ predicateSemantics.ts(65,6): error TS2304: Cannot find name 'identifier'.
         return this ?? 0;
     }
     
+    // positive numbers
+    while (+2) {}
+           ~~
+!!! error TS2872: This kind of expression is always truthy.
+    while (+0.000) {}
+           ~~~~~~
+!!! error TS2873: This kind of expression is always falsy.
+    
     // Not OK; always truthy.
     if (1n) { }
         ~~
diff --git a/tests/baselines/reference/predicateSemantics.js b/tests/baselines/reference/predicateSemantics.js
index 901f61eb2bb91..702f94cd24d39 100644
--- a/tests/baselines/reference/predicateSemantics.js
+++ b/tests/baselines/reference/predicateSemantics.js
@@ -46,6 +46,10 @@ function foo(this: Object | undefined) {
     return this ?? 0;
 }
 
+// positive numbers
+while (+2) {}
+while (+0.000) {}
+
 // Not OK; always truthy.
 if (1n) { }
 
@@ -109,6 +113,9 @@ function foo() {
     // Should be OK
     return this !== null && this !== void 0 ? this : 0;
 }
+// positive numbers
+while (+2) { }
+while (+0.000) { }
 // Not OK; always truthy.
 if (1n) { }
 // Not OK; always falsy.
diff --git a/tests/baselines/reference/predicateSemantics.symbols b/tests/baselines/reference/predicateSemantics.symbols
index 0e82ab24238a2..7420a87891a83 100644
--- a/tests/baselines/reference/predicateSemantics.symbols
+++ b/tests/baselines/reference/predicateSemantics.symbols
@@ -80,6 +80,10 @@ function foo(this: Object | undefined) {
 >this : Symbol(this, Decl(predicateSemantics.ts, 40, 13))
 }
 
+// positive numbers
+while (+2) {}
+while (+0.000) {}
+
 // Not OK; always truthy.
 if (1n) { }
 
diff --git a/tests/baselines/reference/predicateSemantics.types b/tests/baselines/reference/predicateSemantics.types
index 1b131c4a940cd..b5bd8e6324c5e 100644
--- a/tests/baselines/reference/predicateSemantics.types
+++ b/tests/baselines/reference/predicateSemantics.types
@@ -235,6 +235,19 @@ function foo(this: Object | undefined) {
 >  : ^
 }
 
+// positive numbers
+while (+2) {}
+>+2 : 2
+>   : ^
+>2 : 2
+>  : ^
+
+while (+0.000) {}
+>+0.000 : 0
+>       : ^
+>0.000 : 0
+>      : ^
+
 // Not OK; always truthy.
 if (1n) { }
 >1n : 1n
diff --git a/tests/cases/compiler/predicateSemantics.ts b/tests/cases/compiler/predicateSemantics.ts
index c8d7b461d8f61..dbbd8db24ee4f 100644
--- a/tests/cases/compiler/predicateSemantics.ts
+++ b/tests/cases/compiler/predicateSemantics.ts
@@ -43,6 +43,10 @@ function foo(this: Object | undefined) {
     return this ?? 0;
 }
 
+// positive numbers
+while (+2) {}
+while (+0.000) {}
+
 // Not OK; always truthy.
 if (1n) { }
 

From cd552781c713e133532fcbca12d10e61e632a5c3 Mon Sep 17 00:00:00 2001
From: Kirk Waiblinger <kirk.waiblinger@gmail.com>
Date: Thu, 31 Oct 2024 11:33:08 -0600
Subject: [PATCH 3/3] test fixes

---
 .../reference/predicateSemantics.errors.txt   | 41 +++++++++----------
 .../baselines/reference/predicateSemantics.js | 41 ++++++++++---------
 .../reference/predicateSemantics.symbols      | 10 +++++
 .../reference/predicateSemantics.types        | 23 +++++++++++
 tests/cases/compiler/predicateSemantics.ts    |  8 ++++
 5 files changed, 82 insertions(+), 41 deletions(-)

diff --git a/tests/baselines/reference/predicateSemantics.errors.txt b/tests/baselines/reference/predicateSemantics.errors.txt
index 02a2fd93dae7c..d971b5386af2f 100644
--- a/tests/baselines/reference/predicateSemantics.errors.txt
+++ b/tests/baselines/reference/predicateSemantics.errors.txt
@@ -11,22 +11,19 @@ predicateSemantics.ts(35,8): error TS2872: This kind of expression is always tru
 predicateSemantics.ts(36,8): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(47,8): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(48,8): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(51,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
 predicateSemantics.ts(51,5): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(54,5): error TS2737: BigInt literals are not available when targeting lower than ES2020.
 predicateSemantics.ts(54,5): error TS2873: This kind of expression is always falsy.
 predicateSemantics.ts(56,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(56,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
 predicateSemantics.ts(60,5): error TS2872: This kind of expression is always truthy.
 predicateSemantics.ts(62,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(64,5): error TS2873: This kind of expression is always falsy.
-predicateSemantics.ts(64,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(66,5): error TS2872: This kind of expression is always truthy.
-predicateSemantics.ts(66,6): error TS2737: BigInt literals are not available when targeting lower than ES2020.
-predicateSemantics.ts(69,6): error TS2304: Cannot find name 'identifier'.
+predicateSemantics.ts(63,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(65,5): error TS2873: This kind of expression is always falsy.
+predicateSemantics.ts(67,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(70,5): error TS2872: This kind of expression is always truthy.
+predicateSemantics.ts(71,5): error TS2872: This kind of expression is always truthy.
 
 
-==== predicateSemantics.ts (26 errors) ====
+==== predicateSemantics.ts (23 errors) ====
     declare let cond: any;
     
     // OK: One or other operand is possibly nullish
@@ -105,22 +102,16 @@ predicateSemantics.ts(69,6): error TS2304: Cannot find name 'identifier'.
     // Not OK; always truthy.
     if (1n) { }
         ~~
-!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
-        ~~
 !!! error TS2872: This kind of expression is always truthy.
     
     // Not OK; always falsy.
     if (0n) { } 
         ~~
-!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
-        ~~
 !!! error TS2873: This kind of expression is always falsy.
     // Not OK; always falsy.
     if (-0n) { }
         ~~~
 !!! error TS2873: This kind of expression is always falsy.
-         ~~
-!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
     
     // negative numbers
     // not OK - truthy
@@ -130,21 +121,27 @@ predicateSemantics.ts(69,6): error TS2304: Cannot find name 'identifier'.
     // not OK - falsy
     if (-0.0000){}
         ~~~~~~~
+!!! error TS2873: This kind of expression is always falsy.
+    if (+0){}
+        ~~
 !!! error TS2873: This kind of expression is always falsy.
     // not OK - falsy
     if (-0n){}
         ~~~
 !!! error TS2873: This kind of expression is always falsy.
-         ~~
-!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
     // not OK - truthy
     if (-13n){}
         ~~~~
 !!! error TS2872: This kind of expression is always truthy.
-         ~~~
-!!! error TS2737: BigInt literals are not available when targeting lower than ES2020.
     
+    // not ok - just a truthy number
+    if (-1){}
+        ~~
+!!! error TS2872: This kind of expression is always truthy.
+    if (+1){}
+        ~~
+!!! error TS2872: This kind of expression is always truthy.
+    
+    declare const identifier: any;
     // OK
-    if (-identifier) {}
-         ~~~~~~~~~~
-!!! error TS2304: Cannot find name 'identifier'.
\ No newline at end of file
+    if (-identifier) {}
\ No newline at end of file
diff --git a/tests/baselines/reference/predicateSemantics.js b/tests/baselines/reference/predicateSemantics.js
index 702f94cd24d39..db25548fceb0f 100644
--- a/tests/baselines/reference/predicateSemantics.js
+++ b/tests/baselines/reference/predicateSemantics.js
@@ -63,24 +63,29 @@ if (-0n) { }
 if (-1.2) { }
 // not OK - falsy
 if (-0.0000){}
+if (+0){}
 // not OK - falsy
 if (-0n){}
 // not OK - truthy
 if (-13n){}
 
+// not ok - just a truthy number
+if (-1){}
+if (+1){}
+
+declare const identifier: any;
 // OK
 if (-identifier) {}
 
 //// [predicateSemantics.js]
-var _a, _b, _c, _d, _e, _f;
 // OK: One or other operand is possibly nullish
-var test1 = (_a = (cond ? undefined : 32)) !== null && _a !== void 0 ? _a : "possibly reached";
+const test1 = (cond ? undefined : 32) ?? "possibly reached";
 // Not OK: Both operands nullish
-var test2 = (_b = (cond ? undefined : null)) !== null && _b !== void 0 ? _b : "always reached";
+const test2 = (cond ? undefined : null) ?? "always reached";
 // Not OK: Both operands non-nullish
-var test3 = (_c = (cond ? 132 : 17)) !== null && _c !== void 0 ? _c : "unreachable";
+const test3 = (cond ? 132 : 17) ?? "unreachable";
 // Parens
-var test4 = (_d = (cond ? (undefined) : (17))) !== null && _d !== void 0 ? _d : 42;
+const test4 = (cond ? (undefined) : (17)) ?? 42;
 // Should be OK (special case)
 if (!!true) {
 }
@@ -89,19 +94,13 @@ while (0) { }
 while (1) { }
 while (true) { }
 while (false) { }
-var p5 = (_e = {}) !== null && _e !== void 0 ? _e : null;
-var p6 = (_f = 0 > 1) !== null && _f !== void 0 ? _f : null;
-var p7 = null !== null && null !== void 0 ? null : null;
-var p8 = (/** @class */ (function () {
-    function foo() {
-    }
-    return foo;
-}())) && null;
-var p9 = (/** @class */ (function () {
-    function foo() {
-    }
-    return foo;
-}())) || null;
+const p5 = {} ?? null;
+const p6 = 0 > 1 ?? null;
+const p7 = null ?? null;
+const p8 = (class foo {
+}) && null;
+const p9 = (class foo {
+}) || null;
 // Outer expression tests
 while ({}) { }
 while ({}) { }
@@ -111,7 +110,7 @@ while ((({}))) { }
 console.log((cond || undefined) && 1 / cond);
 function foo() {
     // Should be OK
-    return this !== null && this !== void 0 ? this : 0;
+    return this ?? 0;
 }
 // positive numbers
 while (+2) { }
@@ -127,9 +126,13 @@ if (-0n) { }
 if (-1.2) { }
 // not OK - falsy
 if (-0.0000) { }
+if (+0) { }
 // not OK - falsy
 if (-0n) { }
 // not OK - truthy
 if (-13n) { }
+// not ok - just a truthy number
+if (-1) { }
+if (+1) { }
 // OK
 if (-identifier) { }
diff --git a/tests/baselines/reference/predicateSemantics.symbols b/tests/baselines/reference/predicateSemantics.symbols
index 7420a87891a83..0347d5dd08fb8 100644
--- a/tests/baselines/reference/predicateSemantics.symbols
+++ b/tests/baselines/reference/predicateSemantics.symbols
@@ -97,10 +97,20 @@ if (-0n) { }
 if (-1.2) { }
 // not OK - falsy
 if (-0.0000){}
+if (+0){}
 // not OK - falsy
 if (-0n){}
 // not OK - truthy
 if (-13n){}
 
+// not ok - just a truthy number
+if (-1){}
+if (+1){}
+
+declare const identifier: any;
+>identifier : Symbol(identifier, Decl(predicateSemantics.ts, 72, 13))
+
 // OK
 if (-identifier) {}
+>identifier : Symbol(identifier, Decl(predicateSemantics.ts, 72, 13))
+
diff --git a/tests/baselines/reference/predicateSemantics.types b/tests/baselines/reference/predicateSemantics.types
index b5bd8e6324c5e..89ca69d0b2fa4 100644
--- a/tests/baselines/reference/predicateSemantics.types
+++ b/tests/baselines/reference/predicateSemantics.types
@@ -280,6 +280,12 @@ if (-0.0000){}
 >0.0000 : 0
 >       : ^
 
+if (+0){}
+>+0 : 0
+>   : ^
+>0 : 0
+>  : ^
+
 // not OK - falsy
 if (-0n){}
 >-0n : 0n
@@ -294,6 +300,23 @@ if (-13n){}
 >13n : 13n
 >    : ^^^
 
+// not ok - just a truthy number
+if (-1){}
+>-1 : -1
+>   : ^^
+>1 : 1
+>  : ^
+
+if (+1){}
+>+1 : 1
+>   : ^
+>1 : 1
+>  : ^
+
+declare const identifier: any;
+>identifier : any
+>           : ^^^
+
 // OK
 if (-identifier) {}
 >-identifier : number
diff --git a/tests/cases/compiler/predicateSemantics.ts b/tests/cases/compiler/predicateSemantics.ts
index dbbd8db24ee4f..2368ef84b354b 100644
--- a/tests/cases/compiler/predicateSemantics.ts
+++ b/tests/cases/compiler/predicateSemantics.ts
@@ -1,3 +1,5 @@
+// @target: esnext
+
 declare let cond: any;
 
 // OK: One or other operand is possibly nullish
@@ -60,10 +62,16 @@ if (-0n) { }
 if (-1.2) { }
 // not OK - falsy
 if (-0.0000){}
+if (+0){}
 // not OK - falsy
 if (-0n){}
 // not OK - truthy
 if (-13n){}
 
+// not ok - just a truthy number
+if (-1){}
+if (+1){}
+
+declare const identifier: any;
 // OK
 if (-identifier) {}
\ No newline at end of file