eslint: Address no-use-before-define violations

There is only one, and it is because a function expression is used
before it is defined. Changing to a function declaration solves this
because those are hoisted to the top-level (function expressions are
not).

Rule doc page: https://eslint.org/docs/latest/rules/no-use-before-define

.eslintrc.yaml

@@ -20,7 +20,7 @@ globals:
 rules:
   # Code quality rules
   no-unused-vars: ["error", { "argsIgnorePattern": "^_", "destructuredArrayIgnorePattern": "^_" }]
-  # no-use-before-define: ["error", { "functions": false }]
+  no-use-before-define: ["error", { "functions": false }]
   # prefer-const: ["error", {"destructuring": "all"}]
   react/prop-types: off # Remove this override once all props have been typed using PropTypes or TypeScript.
 

src/util/getGenotype.js

@@ -60,12 +60,12 @@ export const decodeColorByGenotype = (colorBy, geneLengths) => {
   return null;
 };
 
-export const decodePositions = (positions, geneLength = 'Infinity') => {
+export function decodePositions(positions, geneLength = 'Infinity') {
   return positions
     .split(",")
     .map((x) => parseInt(x, 10))
     .filter((x) => x > 0 && x <= Math.floor(geneLength));
-};
+}
 
 /**
  * Encode genotype filters for storage in URL query state.