Example

<pre class="language-text"><code class="language-text">complexity/useFlatMap.js:2:1 <a href="/linter/rules/use-flat-map">lint/complexity/useFlatMap</a> <span style="color: #000; background-color: #ddd;"> FIXABLE </span> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ <strong><span style="color: Tomato;"> </span></strong><strong><span style="color: Tomato;">✖</span></strong> <span style="color: Tomato;">The call chain </span><span style="color: Tomato;"><strong>.map().flat()</strong></span><span style="color: Tomato;"> can be replaced with a single </span><span style="color: Tomato;"><strong>.flatMap()</strong></span><span style="color: Tomato;"> call.</span> <strong>1 │ </strong>const array = [&quot;split&quot;, &quot;the text&quot;, &quot;into words&quot;]; <strong><span style="color: Tomato;"> </span></strong><strong><span style="color: Tomato;">&gt;</span></strong> <strong>2 │ </strong>array.map(sentence =&gt; sentence.split(' ')).flat(); <strong> │ </strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong><strong><span style="color: Tomato;">^</span></strong> <strong>3 │ </strong> <strong><span style="color: lightgreen;"> </span></strong><strong><span style="color: lightgreen;">ℹ</span></strong> <span style="color: lightgreen;">Safe fix</span><span style="color: lightgreen;">: </span><span style="color: lightgreen;">Replace the chain with </span><span style="color: lightgreen;"><strong>.flatMap()</strong></span><span style="color: lightgreen;">.</span> <strong>1</strong> <strong>1</strong><strong> │ </strong> const array = [&quot;split&quot;, &quot;the text&quot;, &quot;into words&quot;]; <strong>2</strong> <strong> │ </strong><span style="color: Tomato;">-</span> <span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>r</strong></span><span style="color: Tomato;"><strong>r</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>y</strong></span><span style="color: Tomato;"><strong>.</strong></span><span style="color: Tomato;"><strong>m</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>p</strong></span><span style="color: Tomato;">(</span><span style="color: Tomato;">s</span><span style="color: Tomato;">e</span><span style="color: Tomato;">n</span><span style="color: Tomato;">t</span><span style="color: Tomato;">e</span><span style="color: Tomato;">n</span><span style="color: Tomato;">c</span><span style="color: Tomato;">e</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">=</span><span style="color: Tomato;">&gt;</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">s</span><span style="color: Tomato;">e</span><span style="color: Tomato;">n</span><span style="color: Tomato;">t</span><span style="color: Tomato;">e</span><span style="color: Tomato;">n</span><span style="color: Tomato;">c</span><span style="color: Tomato;">e</span><span style="color: Tomato;">.</span><span style="color: Tomato;">s</span><span style="color: Tomato;">p</span><span style="color: Tomato;">l</span><span style="color: Tomato;">i</span><span style="color: Tomato;">t</span><span style="color: Tomato;">(</span><span style="color: Tomato;">'</span><span style="color: Tomato;"><span style="opacity: 0.8;">·</span></span><span style="color: Tomato;">'</span><span style="color: Tomato;"><strong>)</strong></span><span style="color: Tomato;">)</span><span style="color: Tomato;"><strong>.</strong></span><span style="color: Tomato;"><strong>f</strong></span><span style="color: Tomato;"><strong>l</strong></span><span style="color: Tomato;"><strong>a</strong></span><span style="color: Tomato;"><strong>t</strong></span><span style="color: Tomato;"><strong>(</strong></span><span style="color: Tomato;">)</span><span style="color: Tomato;">;</span> <strong>2</strong><strong> │ </strong><span style="color: MediumSeaGreen;">+</span> <span style="color: MediumSeaGreen;"><strong>a</strong></span><span style="color: MediumSeaGreen;"><strong>r</strong></span><span style="color: MediumSeaGreen;"><strong>r</strong></span><span style="color: MediumSeaGreen;"><strong>a</strong></span><span style="color: MediumSeaGreen;"><strong>y</strong></span><span style="color: MediumSeaGreen;"><strong>.</strong></span><span style="color: MediumSeaGreen;"><strong>f</strong></span><span style="color: MediumSeaGreen;"><strong>l</strong></span><span style="color: MediumSeaGreen;"><strong>a</strong></span><span style="color: MediumSeaGreen;"><strong>t</strong></span><span style="color: MediumSeaGreen;"><strong>M</strong></span><span style="color: MediumSeaGreen;"><strong>a</strong></span><span style="color: MediumSeaGreen;"><strong>p</strong></span><span style="color: MediumSeaGreen;">(</span><span style="color: MediumSeaGreen;">s</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">c</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">=</span><span style="color: MediumSeaGreen;">&gt;</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">s</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">n</span><span style="color: MediumSeaGreen;">c</span><span style="color: MediumSeaGreen;">e</span><span style="color: MediumSeaGreen;">.</span><span style="color: MediumSeaGreen;">s</span><span style="color: MediumSeaGreen;">p</span><span style="color: MediumSeaGreen;">l</span><span style="color: MediumSeaGreen;">i</span><span style="color: MediumSeaGreen;">t</span><span style="color: MediumSeaGreen;">(</span><span style="color: MediumSeaGreen;">'</span><span style="color: MediumSeaGreen;"><span style="opacity: 0.8;">·</span></span><span style="color: MediumSeaGreen;">'</span><span style="color: MediumSeaGreen;">)</span><span style="color: MediumSeaGreen;">)</span><span style="color: MediumSeaGreen;">;</span> <strong>3</strong> <strong>3</strong><strong> │ </strong> </code></pre>