Intersection type — must satisfy all merged properties

What does this output?

// Simulate TypeScript intersection type A & B
// An intersection must have ALL properties from both types

function merge(a, b) {
  return { ...a, ...b };
}

// Serializable = { serialize(): string }
// Loggable     = { log(): void }
// Combined     = Serializable & Loggable = must have both

const serializable = { serialize: () => '{"name":"Alice"}' };
const loggable = { log: () => console.log('logged') };

const combined = merge(serializable, loggable);

// combined has ALL properties from both
console.log(typeof combined.serialize);
console.log(typeof combined.log);
console.log(combined.serialize());

// Check what happens when same key appears (last writer wins at runtime)
const conflicting = merge({ id: 'string-id' }, { id: 42 });
console.log(typeof conflicting.id);  // intersection: string & number = never (TS)
                                      // but at runtime: last value wins

Correct Output

function
function
{"name":"Alice"}
number

Why this output?

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