fix locale import for esm

src/index.tsx

@@ -17,6 +17,7 @@ import { BasicDatePicker, RangeDatePicker } from './pickers';
 import { Locale, SemanticDatepickerProps } from './types';
 import Calendar from './components/calendar';
 import Input from './components/input';
+import localeOptions from "./locales";
 
 const style: React.CSSProperties = {
   display: 'inline-block',
@@ -166,17 +167,15 @@ class SemanticDatepicker extends React.Component<
 
   get locale() {
     const { locale } = this.props;
-
-    let localeJson: Locale;
-
-    try {
-      localeJson = require(`./locales/${locale}.json`);
-    } catch (e) {
+
+    const localeKey = locale.replace("-", "_");
+
+    if (!localeOptions.hasOwnProperty(localeKey)) {
       console.warn(`"${locale}" is not a valid locale`);
-      localeJson = require('./locales/en-US.json');
+      return localeOptions["en_US"];
     }
-
-    return localeJson;
+    
+    return localeOptions[localeKey];
   }
 
   get weekdays() {

src/locales/index.js

@@ -0,0 +1,45 @@
+import bg_BG from "./bg-BG";
+import ca_ES from "./ca-ES";
+import cs_CZ from "./cs-CZ";
+import de_DE from "./de-DE";
+import en_US from "./en-US";
+import es_ES from "./es-ES";
+import et_EE from "./et-EE";
+import fi_FI from "./fi-FI";
+import fr_FR from "./fr-FR";
+import he_IL from "./he-IL";
+import it_IT from './it-IT';
+import ja_JP from "./ja-JP";
+import ko_KR from "./ko-KR";
+import nb_NO from "./nb-NO";
+import nn_NO from "./nn-NO";
+import pl_PL from "./pl-PL";
+import pt_BR from "./pt-BR";
+import ru_RU from "./ru-RU";
+import sv_SE from "./sv-SE";
+import tr_TR from "./tr-TR";
+import zh_CN from "./zh-CN";
+
+export default {
+    bg_BG,
+    ca_ES,
+    cs_CZ,
+    de_DE,
+    en_US,
+    es_ES,
+    et_EE,
+    fi_FI,
+    fr_FR,
+    he_IL,
+    it_IT,
+    ja_JP,
+    ko_KR,
+    nb_NO,
+    nn_NO,
+    pl_PL,
+    pt_BR,
+    ru_RU,
+    sv_SE,
+    tr_TR,
+    zh_CN,
+};