fix: Make trace units be time based (#1387)

* fix: Use time for trace units
* fix test

packages/pyroscope-flamegraph/src/format/format.spec.ts

@@ -37,6 +37,17 @@ describe('format', () => {
         expect(df.format(8000, 100)).toBe('80.00 seconds');
       });
 
+      it('correctly formats trace samples', () => {
+        const df = getFormatter(80, 2, 'trace_samples');
+
+        expect(df.format(0, 100)).toBe('0.00 seconds');
+        expect(df.format(0.001, 100)).toBe('< 0.01 seconds');
+        expect(df.format(100, 100)).toBe('1.00 second');
+        expect(df.format(2000, 100)).toBe('20.00 seconds');
+        expect(df.format(2012.3, 100)).toBe('20.12 seconds');
+        expect(df.format(8000, 100)).toBe('80.00 seconds');
+      });
+
       it('correctly formats duration when maxdur = 80', () => {
         const df = getFormatter(160, 2, 'samples');
 

packages/pyroscope-flamegraph/src/format/format.ts

@@ -29,7 +29,7 @@ export function getFormatter(max: number, sampleRate: number, unit: Units) {
     case 'lock_samples':
       return new ObjectsFormatter(max);
     case 'trace_samples':
-      return new DurationFormatter(max / sampleRate, 'units');
+      return new DurationFormatter(max / sampleRate);
     default:
       console.warn(`Unsupported unit: '${unit}'. Defaulting to ''`);
       return new DurationFormatter(max / sampleRate, ' ');