fix typefacts of intersection (#47583)

Author: gabritto

src/compiler/checker.ts

@@ -135,7 +135,7 @@ namespace ts {
         AllTypeofNE = TypeofNEString | TypeofNENumber | TypeofNEBigInt | TypeofNEBoolean | TypeofNESymbol | TypeofNEObject | TypeofNEFunction | NEUndefined,
         EmptyObjectFacts = All,
         // Masks
-        OrFactsMask = TypeofEQFunction | TypeofEQObject | TypeofNEObject,
+        OrFactsMask = TypeofEQFunction | TypeofNEObject,
         AndFactsMask = All & ~OrFactsMask,
     }
 
@@ -22961,7 +22961,10 @@ namespace ts {
                     (type === falseType || type === regularFalseType) ? TypeFacts.FalseStrictFacts : TypeFacts.TrueStrictFacts :
                     (type === falseType || type === regularFalseType) ? TypeFacts.FalseFacts : TypeFacts.TrueFacts;
             }
-            if (flags & TypeFlags.Object && !ignoreObjects) {
+            if (flags & TypeFlags.Object) {
+                if (ignoreObjects) {
+                    return TypeFacts.AndFactsMask; // This is the identity element for computing type facts of intersection.
+                }
                 return getObjectFlags(type) & ObjectFlags.Anonymous && isEmptyObjectType(type as ObjectType) ?
                     strictNullChecks ? TypeFacts.EmptyObjectStrictFacts : TypeFacts.EmptyObjectFacts :
                     isFunctionObjectType(type as ObjectType) ?

tests/baselines/reference/narrowingTypeofFunction.js

@@ -18,6 +18,12 @@ function f2<T>(x: (T & F) | T & string) {
     else {
         x;
     }
+}
+
+function f3(x: { _foo: number } & number) {
+    if (typeof x === "function") {
+        x;
+    }
 }
 
 //// [narrowingTypeofFunction.js]
@@ -38,3 +44,8 @@ function f2(x) {
         x;
     }
 }
+function f3(x) {
+    if (typeof x === "function") {
+        x;
+    }
+}

tests/baselines/reference/narrowingTypeofFunction.symbols

@@ -43,3 +43,16 @@ function f2<T>(x: (T & F) | T & string) {
 >x : Symbol(x, Decl(narrowingTypeofFunction.ts, 12, 15))
     }
 }
+
+function f3(x: { _foo: number } & number) {
+>f3 : Symbol(f3, Decl(narrowingTypeofFunction.ts, 19, 1))
+>x : Symbol(x, Decl(narrowingTypeofFunction.ts, 21, 12))
+>_foo : Symbol(_foo, Decl(narrowingTypeofFunction.ts, 21, 16))
+
+    if (typeof x === "function") {
+>x : Symbol(x, Decl(narrowingTypeofFunction.ts, 21, 12))
+
+        x;
+>x : Symbol(x, Decl(narrowingTypeofFunction.ts, 21, 12))
+    }
+}

tests/baselines/reference/narrowingTypeofFunction.types

@@ -42,3 +42,19 @@ function f2<T>(x: (T & F) | T & string) {
 >x : T & string
     }
 }
+
+function f3(x: { _foo: number } & number) {
+>f3 : (x: {    _foo: number;} & number) => void
+>x : { _foo: number; } & number
+>_foo : number
+
+    if (typeof x === "function") {
+>typeof x === "function" : boolean
+>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>x : { _foo: number; } & number
+>"function" : "function"
+
+        x;
+>x : never
+    }
+}

tests/baselines/reference/narrowingTypeofObject.js

@@ -0,0 +1,27 @@
+//// [narrowingTypeofObject.ts]
+interface F { (): string }
+
+function test(x: number & { _foo: string }) {
+    if (typeof x === 'object') {
+        x; 
+    }
+}
+
+function f1(x: F & { foo: number }) {
+    if (typeof x !== "object") {
+        x;
+    }
+}
+
+//// [narrowingTypeofObject.js]
+"use strict";
+function test(x) {
+    if (typeof x === 'object') {
+        x;
+    }
+}
+function f1(x) {
+    if (typeof x !== "object") {
+        x;
+    }
+}

tests/baselines/reference/narrowingTypeofObject.symbols

@@ -0,0 +1,30 @@
+=== tests/cases/compiler/narrowingTypeofObject.ts ===
+interface F { (): string }
+>F : Symbol(F, Decl(narrowingTypeofObject.ts, 0, 0))
+
+function test(x: number & { _foo: string }) {
+>test : Symbol(test, Decl(narrowingTypeofObject.ts, 0, 26))
+>x : Symbol(x, Decl(narrowingTypeofObject.ts, 2, 14))
+>_foo : Symbol(_foo, Decl(narrowingTypeofObject.ts, 2, 27))
+
+    if (typeof x === 'object') {
+>x : Symbol(x, Decl(narrowingTypeofObject.ts, 2, 14))
+
+        x; 
+>x : Symbol(x, Decl(narrowingTypeofObject.ts, 2, 14))
+    }
+}
+
+function f1(x: F & { foo: number }) {
+>f1 : Symbol(f1, Decl(narrowingTypeofObject.ts, 6, 1))
+>x : Symbol(x, Decl(narrowingTypeofObject.ts, 8, 12))
+>F : Symbol(F, Decl(narrowingTypeofObject.ts, 0, 0))
+>foo : Symbol(foo, Decl(narrowingTypeofObject.ts, 8, 20))
+
+    if (typeof x !== "object") {
+>x : Symbol(x, Decl(narrowingTypeofObject.ts, 8, 12))
+
+        x;
+>x : Symbol(x, Decl(narrowingTypeofObject.ts, 8, 12))
+    }
+}

tests/baselines/reference/narrowingTypeofObject.types

@@ -0,0 +1,34 @@
+=== tests/cases/compiler/narrowingTypeofObject.ts ===
+interface F { (): string }
+
+function test(x: number & { _foo: string }) {
+>test : (x: number & {    _foo: string;}) => void
+>x : number & { _foo: string; }
+>_foo : string
+
+    if (typeof x === 'object') {
+>typeof x === 'object' : boolean
+>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>x : number & { _foo: string; }
+>'object' : "object"
+
+        x; 
+>x : never
+    }
+}
+
+function f1(x: F & { foo: number }) {
+>f1 : (x: F & {    foo: number;}) => void
+>x : F & { foo: number; }
+>foo : number
+
+    if (typeof x !== "object") {
+>typeof x !== "object" : boolean
+>typeof x : "string" | "number" | "bigint" | "boolean" | "symbol" | "undefined" | "object" | "function"
+>x : F & { foo: number; }
+>"object" : "object"
+
+        x;
+>x : F & { foo: number; }
+    }
+}

tests/cases/compiler/narrowingTypeofFunction.ts

@@ -19,4 +19,10 @@ function f2<T>(x: (T & F) | T & string) {
     else {
         x;
     }
+}
+
+function f3(x: { _foo: number } & number) {
+    if (typeof x === "function") {
+        x;
+    }
 }

tests/cases/compiler/narrowingTypeofObject.ts

@@ -0,0 +1,15 @@
+// @strict: true
+
+interface F { (): string }
+
+function test(x: number & { _foo: string }) {
+    if (typeof x === 'object') {
+        x; 
+    }
+}
+
+function f1(x: F & { foo: number }) {
+    if (typeof x !== "object") {
+        x;
+    }
+}