feat(localize): added MessageFormatLite

packages/localize/src/MessageFormatLite.js

@@ -0,0 +1,39 @@
+/**
+ * Very lightweight message formatter.
+ * It supports 'key replacement' formatting
+ */
+export class MessageFormatLite {
+  constructor(message) {
+    this.message = message;
+  }
+
+  /**
+   * @desc key replacement formatter (supports nested keys)
+   * - from:
+   *   - message: 'replace {key} to {obj.k}'
+   *   - vars: {key: 'val' obj: {k: 'nestedVal'}}
+   * - to: 'replace val to nestedVal'
+   * @param {object} vars key value map of variables to be replaced
+   */
+  format(vars) {
+    if (!vars) {
+      return this.message;
+    }
+    let result = this.message;
+    const varsKeys = Object.keys(vars);
+    const messageKeys = this.message.match(/\{.*?\}/gm) || []; // gets ['{key}', '{obj.k}']
+    messageKeys.forEach(keyWithAccolades => {
+      const k = keyWithAccolades.slice(1, -1);
+      if (varsKeys.includes(k)) {
+        // if '{key}'
+        result = result.replace(`${keyWithAccolades}`, vars[k]);
+      } else if (k.includes('.')) {
+        // if '{obj.k}'
+        const pathKeys = k.split('.');
+        const /** @type {string} */ replacement = pathKeys.reduce((res, acc) => res[acc], vars);
+        result = result.replace(`${keyWithAccolades}`, replacement);
+      }
+    });
+    return result;
+  }
+}