Check previous gear owned before purchasing next level gear (fixes #9071) (#9466)

* add another check if previous gear is owned

* respect gear purchase order

* catch error with miscalculation of equipment number floor

* add integration test for proper equipment purchasing order

* fix syntax

* add 'previousGearNotOwned' string

* rewrite logic for different starting levels for wep vs others

* separate and add tests for armor and weapon

* rename variable for clarification

* skip check if itemIndex is NaN

* change obscure NaN check for readability

* change conditional from checking NaN to Int

test/api/v3/integration/user/buy/POST-user_buy_gear.test.js

@@ -25,12 +25,32 @@ describe('POST /user/buy-gear/:key', () => {
       });
   });
 
-  it('buys a piece of gear', async () => {
+  it('buys the first level weapon gear', async () => {
+    let key = 'weapon_warrior_0';
+
+    await user.post(`/user/buy-gear/${key}`);
+    await user.sync();
+
+    expect(user.items.gear.owned[key]).to.eql(true);
+  });
+
+  it('buys the first level armor gear', async () => {
     let key = 'armor_warrior_1';
 
     await user.post(`/user/buy-gear/${key}`);
     await user.sync();
 
-    expect(user.items.gear.owned.armor_warrior_1).to.eql(true);
+    expect(user.items.gear.owned[key]).to.eql(true);
+  });
+
+  it('tries to buy subsequent, level gear', async () => {
+    let key = 'armor_warrior_2';
+
+    return expect(user.post(`/user/buy-gear/${key}`))
+      .to.eventually.be.rejected.and.eql({
+        code: 401,
+        error: 'NotAuthorized',
+        message: 'You need to purchase a lower level gear before this one.',
+      });
   });
 });