Units: remove unreachable code (#20684)

* Refactor: Remove the code which can't reach

* Test: Add more unit tests for toFixed and scaledUnits methods

- To make them easier to understand

packages/grafana-data/src/valueFormats/valueFormats.test.ts

@@ -1,6 +1,47 @@
 import { toFixed, getValueFormat, scaledUnits } from './valueFormats';
 
 describe('valueFormats', () => {
+  describe('normal cases', () => {
+    it('toFixed should handle number correctly if decimal is null', () => {
+      expect(toFixed(100)).toBe('100');
+
+      expect(toFixed(100.4)).toBe('100');
+      expect(toFixed(100.5)).toBe('101');
+    });
+
+    it('toFixed should handle number correctly if decimal is not null', () => {
+      expect(toFixed(100, 1)).toBe('100.0');
+
+      expect(toFixed(100.37, 1)).toBe('100.4');
+      expect(toFixed(100.63, 1)).toBe('100.6');
+
+      expect(toFixed(100.4, 2)).toBe('100.40');
+      expect(toFixed(100.5, 2)).toBe('100.50');
+    });
+
+    it('scaledUnit should handle number correctly if scaledDecimals is not null', () => {
+      const units = ['', 'K', 'M', 'B', 'T'];
+      const scaler = scaledUnits(1000, units);
+
+      expect(scaler(98765, 0, 0)).toBe('98.765K');
+      expect(scaler(98765, 0, -1)).toBe('98.77K');
+
+      expect(scaler(9876543, 0, 0)).toBe('9.876543M');
+      expect(scaler(9876543, 0, -1)).toBe('9.87654M');
+    });
+
+    it('scaledUnit should handle number correctly if scaledDecimals is null', () => {
+      const units = ['', 'K', 'M', 'B', 'T'];
+      const scaler = scaledUnits(1000, units);
+
+      expect(scaler(98765, 1, null)).toBe('98.8K');
+      expect(scaler(98765, 2, null)).toBe('98.77K');
+
+      expect(scaler(9876543, 2, null)).toBe('9.88M');
+      expect(scaler(9876543, 3, null)).toBe('9.877M');
+    });
+  });
+
   describe('format edge cases', () => {
     const negInf = Number.NEGATIVE_INFINITY.toLocaleString();
     const posInf = Number.POSITIVE_INFINITY.toLocaleString();

packages/grafana-data/src/valueFormats/valueFormats.ts

@@ -66,11 +66,8 @@ export function toFixedScaled(
 ) {
   if (scaledDecimals === null || scaledDecimals === undefined) {
     return toFixed(value, decimals) + ext;
-  } else {
-    return toFixed(value, scaledDecimals + additionalDecimals) + ext;
   }
-
-  return toFixed(value, decimals) + ext;
+  return toFixed(value, scaledDecimals + additionalDecimals) + ext;
 }
 
 export function toFixedUnit(unit: string): ValueFormatter {