Bugfix/singular strings

src/utils/strings.ts

@@ -1,5 +1,22 @@
 // eslint-disable-next-line import/prefer-default-export
 export const singularise = (str: string) => {
-  const lastTwoChars = str.slice(-2);
-  return lastTwoChars === 'es' ? `${str.slice(0, -2)}y` : str.slice(0, -1);
+  // Non-exhaustive singulariser, only handles some common English cases so use with care / add more rules.
+  // Consider adding a string store if really needed.
+  if (str.endsWith('ies')) {
+    // e.g. assemblies, but will fail on species
+    return `${str.slice(0, -3)}y`;
+  }
+  if (str.endsWith('ses')) {
+    // e.g. analyses, but will fail on busses
+    return `${str.slice(0, -3)}sis`;
+  }
+  if (str.endsWith('s')) {
+    // e.g. projects, but will fail on boxes
+    return `${str.slice(0, -1)}`;
+  }
+  if (str.endsWith('a')) {
+    // e.g. data, but will fail on criteria
+    return `${str.slice(0, -1)}um`;
+  }
+  return str;
 };