Rename JSX files with proper .jsx extension (#23733)

app/javascript/mastodon/components/common_counter.jsx

@@ -0,0 +1,62 @@
+// @ts-check
+import React from 'react';
+import { FormattedMessage } from 'react-intl';
+
+/**
+ * Returns custom renderer for one of the common counter types
+ *
+ * @param {"statuses" | "following" | "followers"} counterType
+ * Type of the counter
+ * @param {boolean} isBold Whether display number must be displayed in bold
+ * @returns {(displayNumber: JSX.Element, pluralReady: number) => JSX.Element}
+ * Renderer function
+ * @throws If counterType is not covered by this function
+ */
+export function counterRenderer(counterType, isBold = true) {
+  /**
+   * @type {(displayNumber: JSX.Element) => JSX.Element}
+   */
+  const renderCounter = isBold
+    ? (displayNumber) => <strong>{displayNumber}</strong>
+    : (displayNumber) => displayNumber;
+
+  switch (counterType) {
+  case 'statuses': {
+    return (displayNumber, pluralReady) => (
+      <FormattedMessage
+        id='account.statuses_counter'
+        defaultMessage='{count, plural, one {{counter} Post} other {{counter} Posts}}'
+        values={{
+          count: pluralReady,
+          counter: renderCounter(displayNumber),
+        }}
+      />
+    );
+  }
+  case 'following': {
+    return (displayNumber, pluralReady) => (
+      <FormattedMessage
+        id='account.following_counter'
+        defaultMessage='{count, plural, one {{counter} Following} other {{counter} Following}}'
+        values={{
+          count: pluralReady,
+          counter: renderCounter(displayNumber),
+        }}
+      />
+    );
+  }
+  case 'followers': {
+    return (displayNumber, pluralReady) => (
+      <FormattedMessage
+        id='account.followers_counter'
+        defaultMessage='{count, plural, one {{counter} Follower} other {{counter} Followers}}'
+        values={{
+          count: pluralReady,
+          counter: renderCounter(displayNumber),
+        }}
+      />
+    );
+  }
+  default: throw Error(`Incorrect counter name: ${counterType}. Ensure it accepted by commonCounter function`);
+  }
+}