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//// [typeGuardIntersectionTypes.ts]
interface X {
x: string;
}
interface Y {
y: string;
}
interface Z {
z: string;
}
declare function isX(obj: any): obj is X;
declare function isY(obj: any): obj is Y;
declare function isZ(obj: any): obj is Z;
function f1(obj: Object) {
if (isX(obj) || isY(obj) || isZ(obj)) {
obj;
}
if (isX(obj) && isY(obj) && isZ(obj)) {
obj;
}
}
// Repro from #8911
// two interfaces
interface A {
a: string;
}
interface B {
b: string;
}
// a type guard for B
function isB(toTest: any): toTest is B {
return toTest && toTest.b;
}
// a function that turns an A into an A & B
function union(a: A): A & B | null {
if (isB(a)) {
return a;
} else {
return null;
}
}
// Repro from #9016
declare function log(s: string): void;
// Supported beast features
interface Beast { wings?: boolean; legs?: number }
interface Legged { legs: number; }
interface Winged { wings: boolean; }
// Beast feature detection via user-defined type guards
function hasLegs(x: Beast): x is Legged { return x && typeof x.legs === 'number'; }
function hasWings(x: Beast): x is Winged { return x && !!x.wings; }
// Function to identify a given beast by detecting its features
function identifyBeast(beast: Beast) {
// All beasts with legs
if (hasLegs(beast)) {
// All winged beasts with legs
if (hasWings(beast)) {
if (beast.legs === 4) {
log(`pegasus - 4 legs, wings`);
}
else if (beast.legs === 2) {
log(`bird - 2 legs, wings`);
}
else {
log(`unknown - ${beast.legs} legs, wings`);
}
}
// All non-winged beasts with legs
else {
log(`manbearpig - ${beast.legs} legs, no wings`);
}
}
// All beasts without legs
else {
if (hasWings(beast)) {
log(`quetzalcoatl - no legs, wings`)
}
else {
log(`snake - no legs, no wings`)
}
}
}
function beastFoo(beast: Object) {
if (hasWings(beast) && hasLegs(beast)) {
beast; // Winged & Legged
}
else {
beast;
}
if (hasLegs(beast) && hasWings(beast)) {
beast; // Legged & Winged
}
}
//// [typeGuardIntersectionTypes.js]
function f1(obj) {
if (isX(obj) || isY(obj) || isZ(obj)) {
obj;
}
if (isX(obj) && isY(obj) && isZ(obj)) {
obj;
}
}
// a type guard for B
function isB(toTest) {
return toTest && toTest.b;
}
// a function that turns an A into an A & B
function union(a) {
if (isB(a)) {
return a;
}
else {
return null;
}
}
// Beast feature detection via user-defined type guards
function hasLegs(x) { return x && typeof x.legs === 'number'; }
function hasWings(x) { return x && !!x.wings; }
// Function to identify a given beast by detecting its features
function identifyBeast(beast) {
// All beasts with legs
if (hasLegs(beast)) {
// All winged beasts with legs
if (hasWings(beast)) {
if (beast.legs === 4) {
log("pegasus - 4 legs, wings");
}
else if (beast.legs === 2) {
log("bird - 2 legs, wings");
}
else {
log("unknown - " + beast.legs + " legs, wings");
}
}
// All non-winged beasts with legs
else {
log("manbearpig - " + beast.legs + " legs, no wings");
}
}
// All beasts without legs
else {
if (hasWings(beast)) {
log("quetzalcoatl - no legs, wings");
}
else {
log("snake - no legs, no wings");
}
}
}
function beastFoo(beast) {
if (hasWings(beast) && hasLegs(beast)) {
beast; // Winged & Legged
}
else {
beast;
}
if (hasLegs(beast) && hasWings(beast)) {
beast; // Legged & Winged
}
}
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