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ahejlsbergahejlsberg
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Merge pull request microsoft#24627 from Microsoft/typeofFunction
Fix typeof x === "function" type guards
2 parents 64c3665 + 8b38d35 commit 667de4b

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5 files changed

+566
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‎src/compiler/checker.ts

Lines changed: 4 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -14112,11 +14112,14 @@ namespace ts {
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if (operator === SyntaxKind.ExclamationEqualsToken || operator === SyntaxKind.ExclamationEqualsEqualsToken) {
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assumeTrue = !assumeTrue;
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}
14115+
if (type.flags & TypeFlags.Any && literal.text === "function") {
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return type;
14117+
}
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if (assumeTrue && !(type.flags & TypeFlags.Union)) {
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// We narrow a non-union type to an exact primitive type if the non-union type
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// is a supertype of that primitive type. For example, type 'any' can be narrowed
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// to one of the primitive types.
14119-
const targetType = typeofTypesByName.get(literal.text);
14122+
const targetType = literal.text === "function" ? globalFunctionType : typeofTypesByName.get(literal.text);
1412014123
if (targetType) {
1412114124
if (isTypeSubtypeOf(targetType, type)) {
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return targetType;

‎tests/baselines/reference/typeGuardOfFormTypeOfFunction.js

Lines changed: 139 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,139 @@
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//// [typeGuardOfFormTypeOfFunction.ts]
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function f1(x: any) {
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if (typeof x === "function") {
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x; // any
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}
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}
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function f2(x: unknown) {
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if (typeof x === "function") {
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x; // Function
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}
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}
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function f3(x: {}) {
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if (typeof x === "function") {
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x; // Function
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}
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}
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function f4<T>(x: T) {
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if (typeof x === "function") {
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x; // T & Function
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}
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}
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function f5(x: { s: string }) {
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if (typeof x === "function") {
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x; // never
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}
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}
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function f6(x: () => string) {
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if (typeof x === "function") {
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x; // () => string
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}
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}
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function f10(x: string | (() => string)) {
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if (typeof x === "function") {
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x; // () => string
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}
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else {
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x; // string
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}
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}
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function f11(x: { s: string } | (() => string)) {
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if (typeof x === "function") {
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x; // () => string
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}
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else {
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x; // { s: string }
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}
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}
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function f12(x: { s: string } | { n: number }) {
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if (typeof x === "function") {
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x; // never
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}
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else {
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x; // { s: string } | { n: number }
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}
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}
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// Repro from #18238
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function f100<T, K extends keyof T>(obj: T, keys: K[]) : void {
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for (const k of keys) {
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const item = obj[k];
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if (typeof item == 'function')
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item.call(obj);
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}
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}
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//// [typeGuardOfFormTypeOfFunction.js]
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function f1(x) {
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if (typeof x === "function") {
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x; // any
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}
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}
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function f2(x) {
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if (typeof x === "function") {
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x; // Function
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}
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}
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function f3(x) {
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if (typeof x === "function") {
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x; // Function
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}
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}
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function f4(x) {
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if (typeof x === "function") {
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x; // T & Function
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}
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}
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function f5(x) {
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if (typeof x === "function") {
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x; // never
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}
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}
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function f6(x) {
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if (typeof x === "function") {
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x; // () => string
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}
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}
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function f10(x) {
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if (typeof x === "function") {
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x; // () => string
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}
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else {
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x; // string
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}
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}
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function f11(x) {
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if (typeof x === "function") {
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x; // () => string
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}
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else {
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x; // { s: string }
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}
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}
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function f12(x) {
124+
if (typeof x === "function") {
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x; // never
126+
}
127+
else {
128+
x; // { s: string } | { n: number }
129+
}
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}
131+
// Repro from #18238
132+
function f100(obj, keys) {
133+
for (var _i = 0, keys_1 = keys; _i < keys_1.length; _i++) {
134+
var k = keys_1[_i];
135+
var item = obj[k];
136+
if (typeof item == 'function')
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item.call(obj);
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}
139+
}

‎tests/baselines/reference/typeGuardOfFormTypeOfFunction.symbols

Lines changed: 159 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -0,0 +1,159 @@
1+
=== tests/cases/conformance/expressions/typeGuards/typeGuardOfFormTypeOfFunction.ts ===
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function f1(x: any) {
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>f1 : Symbol(f1, Decl(typeGuardOfFormTypeOfFunction.ts, 0, 0))
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 0, 12))
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if (typeof x === "function") {
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 0, 12))
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x; // any
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 0, 12))
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}
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}
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function f2(x: unknown) {
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>f2 : Symbol(f2, Decl(typeGuardOfFormTypeOfFunction.ts, 4, 1))
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 6, 12))
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if (typeof x === "function") {
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 6, 12))
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x; // Function
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 6, 12))
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}
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}
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function f3(x: {}) {
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>f3 : Symbol(f3, Decl(typeGuardOfFormTypeOfFunction.ts, 10, 1))
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 12, 12))
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if (typeof x === "function") {
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 12, 12))
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x; // Function
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 12, 12))
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}
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}
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function f4<T>(x: T) {
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>f4 : Symbol(f4, Decl(typeGuardOfFormTypeOfFunction.ts, 16, 1))
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>T : Symbol(T, Decl(typeGuardOfFormTypeOfFunction.ts, 18, 12))
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 18, 15))
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>T : Symbol(T, Decl(typeGuardOfFormTypeOfFunction.ts, 18, 12))
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if (typeof x === "function") {
45+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 18, 15))
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x; // T & Function
48+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 18, 15))
49+
}
50+
}
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function f5(x: { s: string }) {
53+
>f5 : Symbol(f5, Decl(typeGuardOfFormTypeOfFunction.ts, 22, 1))
54+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 24, 12))
55+
>s : Symbol(s, Decl(typeGuardOfFormTypeOfFunction.ts, 24, 16))
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57+
if (typeof x === "function") {
58+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 24, 12))
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x; // never
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 24, 12))
62+
}
63+
}
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function f6(x: () => string) {
66+
>f6 : Symbol(f6, Decl(typeGuardOfFormTypeOfFunction.ts, 28, 1))
67+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 30, 12))
68+
69+
if (typeof x === "function") {
70+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 30, 12))
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x; // () => string
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 30, 12))
74+
}
75+
}
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function f10(x: string | (() => string)) {
78+
>f10 : Symbol(f10, Decl(typeGuardOfFormTypeOfFunction.ts, 34, 1))
79+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 36, 13))
80+
81+
if (typeof x === "function") {
82+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 36, 13))
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x; // () => string
85+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 36, 13))
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}
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else {
88+
x; // string
89+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 36, 13))
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}
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}
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function f11(x: { s: string } | (() => string)) {
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>f11 : Symbol(f11, Decl(typeGuardOfFormTypeOfFunction.ts, 43, 1))
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 45, 13))
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>s : Symbol(s, Decl(typeGuardOfFormTypeOfFunction.ts, 45, 17))
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if (typeof x === "function") {
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 45, 13))
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x; // () => string
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 45, 13))
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}
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else {
105+
x; // { s: string }
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 45, 13))
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}
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}
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function f12(x: { s: string } | { n: number }) {
111+
>f12 : Symbol(f12, Decl(typeGuardOfFormTypeOfFunction.ts, 52, 1))
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 54, 13))
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>s : Symbol(s, Decl(typeGuardOfFormTypeOfFunction.ts, 54, 17))
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>n : Symbol(n, Decl(typeGuardOfFormTypeOfFunction.ts, 54, 33))
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if (typeof x === "function") {
117+
>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 54, 13))
118+
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x; // never
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 54, 13))
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}
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else {
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x; // { s: string } | { n: number }
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>x : Symbol(x, Decl(typeGuardOfFormTypeOfFunction.ts, 54, 13))
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}
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}
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// Repro from #18238
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function f100<T, K extends keyof T>(obj: T, keys: K[]) : void {
131+
>f100 : Symbol(f100, Decl(typeGuardOfFormTypeOfFunction.ts, 61, 1))
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>T : Symbol(T, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 14))
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>K : Symbol(K, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 16))
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>T : Symbol(T, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 14))
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>obj : Symbol(obj, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 36))
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>T : Symbol(T, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 14))
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>keys : Symbol(keys, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 43))
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>K : Symbol(K, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 16))
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for (const k of keys) {
141+
>k : Symbol(k, Decl(typeGuardOfFormTypeOfFunction.ts, 66, 14))
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>keys : Symbol(keys, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 43))
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const item = obj[k];
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>item : Symbol(item, Decl(typeGuardOfFormTypeOfFunction.ts, 67, 13))
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>obj : Symbol(obj, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 36))
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>k : Symbol(k, Decl(typeGuardOfFormTypeOfFunction.ts, 66, 14))
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if (typeof item == 'function')
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>item : Symbol(item, Decl(typeGuardOfFormTypeOfFunction.ts, 67, 13))
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item.call(obj);
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>item.call : Symbol(Function.call, Decl(lib.d.ts, --, --))
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>item : Symbol(item, Decl(typeGuardOfFormTypeOfFunction.ts, 67, 13))
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>call : Symbol(Function.call, Decl(lib.d.ts, --, --))
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>obj : Symbol(obj, Decl(typeGuardOfFormTypeOfFunction.ts, 65, 36))
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}
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}
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