Fixed narrowing based on aliased discriminants coming from destructured parameters

src/compiler/checker.ts

@@ -476,6 +476,7 @@ import {
     isCallOrNewExpression,
     isCallSignatureDeclaration,
     isCatchClause,
+    isCatchClauseVariableDeclaration,
     isCatchClauseVariableDeclarationOrBindingElement,
     isCheckJsEnabledForFile,
     isClassDeclaration,
@@ -27461,7 +27462,9 @@ export function createTypeChecker(host: TypeCheckerHost): TypeChecker {
             case SyntaxKind.ObjectBindingPattern:
             case SyntaxKind.ArrayBindingPattern:
                 const rootDeclaration = getRootDeclaration(node.parent);
-                return isVariableDeclaration(rootDeclaration) && isVarConstLike(rootDeclaration);
+                return isParameter(rootDeclaration) || isCatchClauseVariableDeclaration(rootDeclaration)
+                    ? !isSomeSymbolAssigned(rootDeclaration)
+                    : isVariableDeclaration(rootDeclaration) && isVarConstLike(rootDeclaration);
         }
         return false;
     }

tests/baselines/reference/controlFlowAliasedDiscriminants.errors.txt

@@ -126,4 +126,14 @@ controlFlowAliasedDiscriminants.ts(98,19): error TS1360: Type 'string | number'
             resp.resp.data satisfies string;
         }    
     }
+
+    function bindingPatternInParameter({ data: data1, isSuccess: isSuccess1 }: UseQueryResult<number>) {
+      const { data: data2, isSuccess: isSuccess2 } = useQuery();
+
+      const areSuccess = isSuccess1 && isSuccess2;
+      if (areSuccess) {
+        data1.toExponential();
+        data2.toExponential();
+      }
+    }
 

tests/baselines/reference/controlFlowAliasedDiscriminants.js

@@ -104,9 +104,20 @@ type Nested = {
         resp.resp.data satisfies string;
     }    
 }
+
+function bindingPatternInParameter({ data: data1, isSuccess: isSuccess1 }: UseQueryResult<number>) {
+  const { data: data2, isSuccess: isSuccess2 } = useQuery();
+
+  const areSuccess = isSuccess1 && isSuccess2;
+  if (areSuccess) {
+    data1.toExponential();
+    data2.toExponential();
+  }
+}
 
 
 //// [controlFlowAliasedDiscriminants.js]
+"use strict";
 function useQuery() {
     return {
         isSuccess: false,
@@ -180,3 +191,12 @@ if (areSuccess) {
         resp.resp.data;
     }
 }
+function bindingPatternInParameter(_a) {
+    var data1 = _a.data, isSuccess1 = _a.isSuccess;
+    var _b = useQuery(), data2 = _b.data, isSuccess2 = _b.isSuccess;
+    var areSuccess = isSuccess1 && isSuccess2;
+    if (areSuccess) {
+        data1.toExponential();
+        data2.toExponential();
+    }
+}

tests/baselines/reference/controlFlowAliasedDiscriminants.symbols

@@ -325,3 +325,38 @@ type Nested = {
     }    
 }
 
+function bindingPatternInParameter({ data: data1, isSuccess: isSuccess1 }: UseQueryResult<number>) {
+>bindingPatternInParameter : Symbol(bindingPatternInParameter, Decl(controlFlowAliasedDiscriminants.ts, 102, 1))
+>data : Symbol(data, Decl(controlFlowAliasedDiscriminants.ts, 1, 21), Decl(controlFlowAliasedDiscriminants.ts, 4, 20))
+>data1 : Symbol(data1, Decl(controlFlowAliasedDiscriminants.ts, 104, 36))
+>isSuccess : Symbol(isSuccess, Decl(controlFlowAliasedDiscriminants.ts, 0, 26), Decl(controlFlowAliasedDiscriminants.ts, 3, 5))
+>isSuccess1 : Symbol(isSuccess1, Decl(controlFlowAliasedDiscriminants.ts, 104, 49))
+>UseQueryResult : Symbol(UseQueryResult, Decl(controlFlowAliasedDiscriminants.ts, 0, 0))
+
+  const { data: data2, isSuccess: isSuccess2 } = useQuery();
+>data : Symbol(data, Decl(controlFlowAliasedDiscriminants.ts, 1, 21), Decl(controlFlowAliasedDiscriminants.ts, 4, 20))
+>data2 : Symbol(data2, Decl(controlFlowAliasedDiscriminants.ts, 105, 9))
+>isSuccess : Symbol(isSuccess, Decl(controlFlowAliasedDiscriminants.ts, 0, 26), Decl(controlFlowAliasedDiscriminants.ts, 3, 5))
+>isSuccess2 : Symbol(isSuccess2, Decl(controlFlowAliasedDiscriminants.ts, 105, 22))
+>useQuery : Symbol(useQuery, Decl(controlFlowAliasedDiscriminants.ts, 6, 2))
+
+  const areSuccess = isSuccess1 && isSuccess2;
+>areSuccess : Symbol(areSuccess, Decl(controlFlowAliasedDiscriminants.ts, 107, 7))
+>isSuccess1 : Symbol(isSuccess1, Decl(controlFlowAliasedDiscriminants.ts, 104, 49))
+>isSuccess2 : Symbol(isSuccess2, Decl(controlFlowAliasedDiscriminants.ts, 105, 22))
+
+  if (areSuccess) {
+>areSuccess : Symbol(areSuccess, Decl(controlFlowAliasedDiscriminants.ts, 107, 7))
+
+    data1.toExponential();
+>data1.toExponential : Symbol(Number.toExponential, Decl(lib.es5.d.ts, --, --))
+>data1 : Symbol(data1, Decl(controlFlowAliasedDiscriminants.ts, 104, 36))
+>toExponential : Symbol(Number.toExponential, Decl(lib.es5.d.ts, --, --))
+
+    data2.toExponential();
+>data2.toExponential : Symbol(Number.toExponential, Decl(lib.es5.d.ts, --, --))
+>data2 : Symbol(data2, Decl(controlFlowAliasedDiscriminants.ts, 105, 9))
+>toExponential : Symbol(Number.toExponential, Decl(lib.es5.d.ts, --, --))
+  }
+}
+

tests/baselines/reference/controlFlowAliasedDiscriminants.types

@@ -376,3 +376,41 @@ type Nested = {
     }    
 }
 
+function bindingPatternInParameter({ data: data1, isSuccess: isSuccess1 }: UseQueryResult<number>) {
+>bindingPatternInParameter : ({ data: data1, isSuccess: isSuccess1 }: UseQueryResult<number>) => void
+>data : any
+>data1 : number | undefined
+>isSuccess : any
+>isSuccess1 : boolean
+
+  const { data: data2, isSuccess: isSuccess2 } = useQuery();
+>data : any
+>data2 : number | undefined
+>isSuccess : any
+>isSuccess2 : boolean
+>useQuery() : UseQueryResult<number>
+>useQuery : () => UseQueryResult<number>
+
+  const areSuccess = isSuccess1 && isSuccess2;
+>areSuccess : boolean
+>isSuccess1 && isSuccess2 : boolean
+>isSuccess1 : boolean
+>isSuccess2 : boolean
+
+  if (areSuccess) {
+>areSuccess : boolean
+
+    data1.toExponential();
+>data1.toExponential() : string
+>data1.toExponential : (fractionDigits?: number | undefined) => string
+>data1 : number
+>toExponential : (fractionDigits?: number | undefined) => string
+
+    data2.toExponential();
+>data2.toExponential() : string
+>data2.toExponential : (fractionDigits?: number | undefined) => string
+>data2 : number
+>toExponential : (fractionDigits?: number | undefined) => string
+  }
+}
+

tests/cases/compiler/controlFlowAliasedDiscriminants.ts

@@ -1,5 +1,4 @@
-// @strictNullChecks: true
-// @noImplicitAny: true
+// @strict: true
 
 type UseQueryResult<T> = {
     isSuccess: false;
@@ -104,3 +103,13 @@ type Nested = {
         resp.resp.data satisfies string;
     }    
 }
+
+function bindingPatternInParameter({ data: data1, isSuccess: isSuccess1 }: UseQueryResult<number>) {
+  const { data: data2, isSuccess: isSuccess2 } = useQuery();
+
+  const areSuccess = isSuccess1 && isSuccess2;
+  if (areSuccess) {
+    data1.toExponential();
+    data2.toExponential();
+  }
+}