<p dir="auto">Shouldn't below code give me red squiggles on the duplicate overloaded signature?</p>
<div class="highlight highlight-source-ts notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="function f(a: string, b: number): boolean;
function f(a: string, b: number): boolean;
function f(a: string, b?: string | number, c?: string): boolean {
    return true;
}"><pre class="notranslate"><span class="pl-k">function</span> <span class="pl-s1">f</span><span class="pl-kos">(</span><span class="pl-s1">a</span>: <span class="pl-smi">string</span><span class="pl-kos">,</span> <span class="pl-s1">b</span>: <span class="pl-smi">number</span><span class="pl-kos">)</span>: <span class="pl-smi">boolean</span><span class="pl-kos">;</span>
<span class="pl-k">function</span> <span class="pl-s1">f</span><span class="pl-kos">(</span><span class="pl-s1">a</span>: <span class="pl-smi">string</span><span class="pl-kos">,</span> <span class="pl-s1">b</span>: <span class="pl-smi">number</span><span class="pl-kos">)</span>: <span class="pl-smi">boolean</span><span class="pl-kos">;</span>
<span class="pl-k">function</span> <span class="pl-en">f</span><span class="pl-kos">(</span><span class="pl-s1">a</span>: <span class="pl-smi">string</span><span class="pl-kos">,</span> <span class="pl-s1">b</span>?: <span class="pl-smi">string</span> <span class="pl-c1">|</span> <span class="pl-smi">number</span><span class="pl-kos">,</span> <span class="pl-s1">c</span>?: <span class="pl-smi">string</span><span class="pl-kos">)</span>: <span class="pl-smi">boolean</span> <span class="pl-kos">{</span>
    <span class="pl-k">return</span> <span class="pl-c1">true</span><span class="pl-kos">;</span>
<span class="pl-kos">}</span></pre></div>
<div class="highlight highlight-source-ts notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="interface A {
    a();     
    a();     
    a();     
}            "><pre class="notranslate"><span class="pl-k">interface</span> <span class="pl-smi">A</span> <span class="pl-kos">{</span>
    <span class="pl-c1">a</span><span class="pl-kos">(</span><span class="pl-kos">)</span><span class="pl-kos">;</span>     
    <span class="pl-c1">a</span><span class="pl-kos">(</span><span class="pl-kos">)</span><span class="pl-kos">;</span>     
    <span class="pl-c1">a</span><span class="pl-kos">(</span><span class="pl-kos">)</span><span class="pl-kos">;</span>     
<span class="pl-kos">}</span>            </pre></div>
<p dir="auto">Expected:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="file.ts(2,5): error TSxxxx: Duplicate overload signature for 'a'.
file.ts(3,5): error TSxxxx: Duplicate overload signature for 'a'.
file.ts(4,5): error TSxxxx: Duplicate overload signature for 'a'."><pre class="notranslate"><code class="notranslate">file.ts(2,5): error TSxxxx: Duplicate overload signature for 'a'.
file.ts(3,5): error TSxxxx: Duplicate overload signature for 'a'.
file.ts(4,5): error TSxxxx: Duplicate overload signature for 'a'.
</code></pre></div>
<p dir="auto">Actual:</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content=""><pre class="notranslate"><code class="notranslate"></code></pre></div>
<p dir="auto">(no error)</p>
<hr>
<p dir="auto">Apparently the following also gives no error:</p>
<div class="highlight highlight-source-ts notranslate position-relative overflow-auto" dir="auto" data-snippet-clipboard-copy-content="function f();
function f();
function f() {
}"><pre class="notranslate"><span class="pl-k">function</span> <span class="pl-s1">f</span><span class="pl-kos">(</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-k">function</span> <span class="pl-s1">f</span><span class="pl-kos">(</span><span class="pl-kos">)</span><span class="pl-kos">;</span>
<span class="pl-k">function</span> <span class="pl-en">f</span><span class="pl-kos">(</span><span class="pl-kos">)</span> <span class="pl-kos">{</span>
<span class="pl-kos">}</span></pre></div>