title: How to satisfy the lint rules 'array-callback-return'?
body: <p>This is my first cut:</p>
  
  <pre><code>const planLimits = {plan1: {condition1: 50, ...}}
  
  function initialisePlanLimits(planLimits) {
    const limits = new Map();
    Object.keys(planLimits).map((planId) =&gt; (
      const limitMap = new Map(Object.entries(planLimits[planId]));
      limits.set(planId, limitMap);
    ));
    return limits;
  }
  </code></pre>
  
  <p>The linter flags this error: <code>error  Expected to return a value in this function                                                    array-callback-return</code></p>
  
  <p>So I changed to this version:</p>
  
  <pre><code>function initialisePlanLimits(planLimits) {
    const limits = new Map();
    Object.keys(planLimits).map((planId) =&gt; (
      limits.set(planId, new Map(Object.entries(planLimits[planId])))
    ));
    return limits;
  }
  </code></pre>
  
  <p>It throws another error <code>Unexpected parentheses around single function argument having a body with no curly braces      arrow-parens</code></p>
  
  <p>My questions:</p>
  
  <p>1) I reckon I can fix my first version by sticking in a <code>return null</code> within the curry bracket. But is there a better, more elegant way? A bogus return statement does not make sense in this context</p>
  
  <p>2) Why the second version fails? Isn't it equivalent to the first version? </p>