Fixed detection of optional chains containing a reference

tsc/internal/checker/flow.go

@@ -1596,7 +1596,7 @@ func (c *Checker) reportFlowControlError(node *ast.Node) {
 
 func (c *Checker) isMatchingReference(source *ast.Node, target *ast.Node) bool {
 	switch target.Kind {
-	case ast.KindParenthesizedExpression, ast.KindNonNullExpression:
+	case ast.KindParenthesizedExpression, ast.KindNonNullExpression, ast.KindSatisfiesExpression:
 		return c.isMatchingReference(source, target.Expression())
 	case ast.KindBinaryExpression:
 		return ast.IsAssignmentExpression(target, false) && c.isMatchingReference(source, target.AsBinaryExpression().Left) ||
@@ -1851,7 +1851,7 @@ func (c *Checker) containsMatchingReference(source *ast.Node, target *ast.Node)
 func (c *Checker) optionalChainContainsReference(source *ast.Node, target *ast.Node) bool {
 	for ast.IsOptionalChain(source) {
 		source = source.Expression()
-		if c.isMatchingReference(source, target) {
+		if c.isMatchingReference(target, source) {
 			return true
 		}
 	}

tsc/testdata/baselines/reference/compiler/narrowByEquality.errors.txt

@@ -86,4 +86,9 @@ narrowByEquality.ts(55,9): error TS2322: Type 'string | number' is not assignabl
         xUnknown;
     }
 
+    declare let option: { type: string } | undefined;
+
+    if ((option satisfies { type: string } | undefined) !== undefined) {
+        option.type;
+    }
 

tsc/testdata/baselines/reference/compiler/narrowByEquality.js

@@ -73,6 +73,11 @@ if (xUnknown != null) {
     xUnknown;
 }
 
+declare let option: { type: string } | undefined;
+
+if ((option satisfies { type: string } | undefined) !== undefined) {
+    option.type;
+}
 
 
 //// [narrowByEquality.js]
@@ -129,3 +134,6 @@ if (xUnknown != null) {
 else {
     xUnknown;
 }
+if (option !== undefined) {
+    option.type;
+}

tsc/testdata/baselines/reference/compiler/narrowByEquality.symbols

@@ -139,4 +139,18 @@ if (xUnknown != null) {
 >xUnknown : Symbol(xUnknown, Decl(narrowByEquality.ts, 4, 11))
 }
 
+declare let option: { type: string } | undefined;
+>option : Symbol(option, Decl(narrowByEquality.ts, 72, 11))
+>type : Symbol(type, Decl(narrowByEquality.ts, 72, 21))
+
+if ((option satisfies { type: string } | undefined) !== undefined) {
+>option : Symbol(option, Decl(narrowByEquality.ts, 72, 11))
+>type : Symbol(type, Decl(narrowByEquality.ts, 74, 23))
+>undefined : Symbol(undefined)
+
+    option.type;
+>option.type : Symbol(type, Decl(narrowByEquality.ts, 72, 21))
+>option : Symbol(option, Decl(narrowByEquality.ts, 72, 11))
+>type : Symbol(type, Decl(narrowByEquality.ts, 72, 21))
+}
 

tsc/testdata/baselines/reference/compiler/narrowByEquality.types

@@ -160,4 +160,21 @@ if (xUnknown != null) {
 >xUnknown : null | undefined
 }
 
+declare let option: { type: string } | undefined;
+>option : { type: string; } | undefined
+>type : string
+
+if ((option satisfies { type: string } | undefined) !== undefined) {
+>(option satisfies { type: string } | undefined) !== undefined : boolean
+>(option satisfies { type: string } | undefined) : { type: string; } | undefined
+>option satisfies { type: string } | undefined : { type: string; } | undefined
+>option : { type: string; } | undefined
+>type : string
+>undefined : undefined
+
+    option.type;
+>option.type : string
+>option : { type: string; }
+>type : string
+}
 

tsc/testdata/baselines/reference/conformance/controlFlowOptionalChain4.errors.txt

@@ -0,0 +1,93 @@
+controlFlowOptionalChain4.ts(54,9): error TS18048: 'option' is possibly 'undefined'.
+controlFlowOptionalChain4.ts(62,9): error TS18048: 'option' is possibly 'undefined'.
+controlFlowOptionalChain4.ts(70,9): error TS18048: 'option' is possibly 'undefined'.
+
+
+==== controlFlowOptionalChain4.ts (3 errors) ====
+    // https://github.com/microsoft/TypeScript/issues/56998
+
+    type Type = {
+        id: number;
+    };
+
+    type InferenceInfo = {
+        typeParameter: Type;
+        impliedArity?: number;
+    };
+
+    declare function getInferenceInfoForType(type: Type): InferenceInfo | undefined;
+
+    function fn1(t1: Type, t2: Type) {
+        let info = getInferenceInfoForType(t1);
+        if (info?.impliedArity !== undefined) {
+            info.impliedArity;
+        }
+        else if ((info = getInferenceInfoForType(t2))?.impliedArity !== undefined) {
+            info.impliedArity;
+        }
+    }
+
+    function fn2(t1: Type, t2: Type) {
+        let info = getInferenceInfoForType(t1);
+        if (info?.impliedArity !== undefined) {
+            info.impliedArity;
+        }
+        else if ((info = getInferenceInfoForType(t2))?.impliedArity) {
+            info.impliedArity;
+        }
+    }
+
+    // https://github.com/microsoft/TypeScript/issues/60855
+
+    type Option = { type: "Some"; value: number; } | { type: "None"; };
+
+    declare function someOptionalOption(): Option | undefined;
+
+    function test60855(): number | undefined {
+        let option: Option | undefined;
+
+        if ((option = someOptionalOption())?.type === "Some") {
+            return option.value;
+        }
+
+        return undefined;
+    }
+
+    function testEqualityWithUndefined() {
+        let option: Option | undefined;
+
+        if ((option = someOptionalOption())?.type === undefined) {
+            option.type;
+            ~~~~~~
+!!! error TS18048: 'option' is possibly 'undefined'.
+        }
+    }
+
+    function testNegativeEquality() {
+        let option: Option | undefined;
+
+        if ((option = someOptionalOption())?.type !== "Some") {
+            option.type;
+            ~~~~~~
+!!! error TS18048: 'option' is possibly 'undefined'.
+        }
+    }
+
+    function testFalsyBranch() {
+        let option: Option | undefined;
+
+        if (!(option = someOptionalOption())?.type) {
+            option.type;
+            ~~~~~~
+!!! error TS18048: 'option' is possibly 'undefined'.
+        }
+    }
+
+    function testAssignmentWithSatisfies() {
+        let option: Option | undefined;
+
+        if ((option = someOptionalOption() satisfies Option | undefined)?.type === "Some") {
+            option.value;
+        }
+    }
+