fix(core/serverGroup): Correct 'simple scaling' heuristic (#7385)

* fix(core/serverGroup): Correct 'simple scaling' heuristic

This was seemingly introduced from 6630f9b

The regression is that the "Capacity" section always considers the scaling mode to be "simple", and doesn't show the actual min/max capacity numbers, only Desired.

Noticed using an AWS account.

* fix(core/serverGroup): Adding test for capacity details

app/scripts/modules/core/src/serverGroup/details/capacity/CapacityDetailsSection.spec.tsx

@@ -0,0 +1,17 @@
+import * as React from 'react';
+import { mount } from 'enzyme';
+
+import { CapacityDetailsSection } from './CapacityDetailsSection';
+
+describe('<CapacityDetailsSection/>', function () {
+  it('when min === max, it should be displayed in simplemode', function () {
+    const component = mount(<CapacityDetailsSection capacity={{ min: 9, max: 9, desired: 4 }} current={5}/>);
+    expect(component.contains(<dt>Min/Max</dt>)).toBe(true);
+  });
+
+  it('when min !== max, it should display the different min and max separately', function () {
+    const component = mount(<CapacityDetailsSection capacity={{ min: 1, max: 9, desired: 4 }} current={5}/>);
+    expect(component.contains(<dt>Min</dt>)).toBe(true);
+    expect(component.contains(<dt>Max</dt>)).toBe(true);
+  });
+});

app/scripts/modules/core/src/serverGroup/details/capacity/CapacityDetailsSection.tsx

@@ -11,7 +11,7 @@ interface ICapacityDetailsSectionProps {
 
 export function CapacityDetailsSection(props: ICapacityDetailsSectionProps) {
   const { capacity, current } = props;
-  const simpleMode = capacity.max === capacity.max;
+  const simpleMode = capacity.min === capacity.max;
   return (
     <dl className="dl-horizontal dl-flex">
       <DesiredCapacity capacity={capacity} simpleMode={simpleMode} />