Tests for label stats calculation

public/app/core/specs/logs_model.test.ts

@@ -1,4 +1,4 @@
-import { dedupLogRows, LogsDedupStrategy, LogsModel } from '../logs_model';
+import { calculateLogsLabelStats, dedupLogRows, LogsDedupStrategy, LogsModel } from '../logs_model';
 
 describe('dedupLogRows()', () => {
   test('should return rows as is when dedup is set to none', () => {
@@ -106,3 +106,56 @@ describe('dedupLogRows()', () => {
     ]);
   });
 });
+
+describe('calculateLogsLabelStats()', () => {
+  test('should return no stats for empty rows', () => {
+    expect(calculateLogsLabelStats([], '')).toEqual([]);
+  });
+
+  test('should return no stats of label is not found', () => {
+    const rows = [
+      {
+        entry: 'foo 1',
+        labels: {
+          foo: 'bar',
+        },
+      },
+    ];
+
+    expect(calculateLogsLabelStats(rows as any, 'baz')).toEqual([]);
+  });
+
+  test('should return stats for found labels', () => {
+    const rows = [
+      {
+        entry: 'foo 1',
+        labels: {
+          foo: 'bar',
+        },
+      },
+      {
+        entry: 'foo 0',
+        labels: {
+          foo: 'xxx',
+        },
+      },
+      {
+        entry: 'foo 2',
+        labels: {
+          foo: 'bar',
+        },
+      },
+    ];
+
+    expect(calculateLogsLabelStats(rows as any, 'foo')).toMatchObject([
+      {
+        value: 'bar',
+        count: 2,
+      },
+      {
+        value: 'xxx',
+        count: 1,
+      },
+    ]);
+  });
+});