fix: Replace humanize string with own implementation. (#250)

* chore: Add a more precise test for the error message formatting.

* fix: Replace humanize-string with own implementation.

* chore: Add new contributors.

lib/defekt.ts

@@ -1,6 +1,6 @@
 import { CustomError } from './CustomError';
 import { ErrorConstructors } from './ErrorConstructors';
-import humanizeString from 'humanize-string';
+import { formatErrorMessage } from './formatErrorMessage';
 
 const defekt = function <TErrorDefinition extends Record<string, { code?: string }>>
 (errorDefinitions: TErrorDefinition): ErrorConstructors<TErrorDefinition> {
@@ -26,7 +26,7 @@ const defekt = function <TErrorDefinition extends Record<string, { code?: string
       public static code: string = code;
 
       /* eslint-disable default-param-last */
-      public constructor (message = `${humanizeString(errorName)}.`, {
+      public constructor (message = formatErrorMessage({ errorName }), {
         cause,
         data
       }: {

lib/formatErrorMessage.ts

@@ -0,0 +1,24 @@
+const formatErrorMessage = function ({ errorName }: {
+  errorName: string;
+}): string {
+  const almostFormattedErrorMessage = errorName.
+    split('').
+    map((character: string, index: number): string => {
+      if (index === 0) {
+        return character.toUpperCase();
+      }
+
+      if (character.toUpperCase() === character) {
+        return ` ${character.toLowerCase()}`;
+      }
+
+      return character;
+    }).
+    join('');
+
+  return `${almostFormattedErrorMessage}.`;
+};
+
+export {
+  formatErrorMessage
+};