chore: note that random element functions could return undefined (#1910)

We should be explicit about the fact that we expect the arrays to not be empty.

Reviewed-on: #1910
Co-authored-by: Sainan <63328889+Sainan@users.noreply.github.com>
Co-committed-by: Sainan <63328889+Sainan@users.noreply.github.com>

src/controllers/api/activateRandomModController.ts

@@ -17,7 +17,7 @@ export const activateRandomModController: RequestHandler = async (req, res) => {
             ItemCount: -1
         }
     ]);
-    const rivenType = getRandomElement(rivenRawToRealWeighted[request.ItemType]);
+    const rivenType = getRandomElement(rivenRawToRealWeighted[request.ItemType])!;
     const fingerprint = createVeiledRivenFingerprint(ExportUpgrades[rivenType]);
     const upgradeIndex =
         inventory.Upgrades.push({

src/controllers/api/artifactTransmutationController.ts

@@ -28,7 +28,7 @@ export const artifactTransmutationController: RequestHandler = async (req, res)
         });
 
         const rawRivenType = getRandomRawRivenType();
-        const rivenType = getRandomElement(rivenRawToRealWeighted[rawRivenType]);
+        const rivenType = getRandomElement(rivenRawToRealWeighted[rawRivenType])!;
         const fingerprint = createVeiledRivenFingerprint(ExportUpgrades[rivenType]);
 
         const upgradeIndex =

src/controllers/api/modularWeaponSaleController.ts

@@ -141,7 +141,7 @@ const getModularWeaponSale = (
     getItemType: (parts: string[]) => string
 ): IModularWeaponSaleInfo => {
     const rng = new CRng(day);
-    const parts = partTypes.map(partType => rng.randomElement(partTypeToParts[partType]));
+    const parts = partTypes.map(partType => rng.randomElement(partTypeToParts[partType])!);
     let partsCost = 0;
     for (const part of parts) {
         partsCost += ExportWeapons[part].premiumPrice!;

src/helpers/rivenHelper.ts

@@ -31,7 +31,7 @@ export interface IFingerprintStat {
 }
 
 export const createVeiledRivenFingerprint = (meta: IUpgrade): IVeiledRivenFingerprint => {
-    const challenge = getRandomElement(meta.availableChallenges!);
+    const challenge = getRandomElement(meta.availableChallenges!)!;
     const fingerprintChallenge: IRivenChallenge = {
         Type: challenge.fullName,
         Progress: 0,
@@ -54,11 +54,11 @@ export const createVeiledRivenFingerprint = (meta: IUpgrade): IVeiledRivenFinger
 
 export const createUnveiledRivenFingerprint = (meta: IUpgrade): IUnveiledRivenFingerprint => {
     const fingerprint: IUnveiledRivenFingerprint = {
-        compat: getRandomElement(meta.compatibleItems!),
+        compat: getRandomElement(meta.compatibleItems!)!,
         lim: 0,
         lvl: 0,
         lvlReq: getRandomInt(8, 16),
-        pol: getRandomElement(["AP_ATTACK", "AP_DEFENSE", "AP_TACTIC"]),
+        pol: getRandomElement(["AP_ATTACK", "AP_DEFENSE", "AP_TACTIC"])!,
         buffs: [],
         curses: []
     };
@@ -81,7 +81,7 @@ export const randomiseRivenStats = (meta: IUpgrade, fingerprint: IUnveiledRivenF
     if (Math.random() < 0.5) {
         const entry = getRandomElement(
             meta.upgradeEntries!.filter(x => x.canBeCurse && !fingerprint.buffs.find(y => y.Tag == x.tag))
-        );
+        )!;
         fingerprint.curses.push({ Tag: entry.tag, Value: Math.trunc(Math.random() * 0x40000000) });
     }
 };

src/services/inventoryService.ts

@@ -1798,7 +1798,7 @@ export const addKeyChainItems = async (
 };
 
 export const createLibraryDailyTask = (): ILibraryDailyTaskInfo => {
-    const enemyTypes = getRandomElement(libraryDailyTasks);
+    const enemyTypes = getRandomElement(libraryDailyTasks)!;
     const enemyAvatar = ExportEnemies.avatars[enemyTypes[0]];
     const scansRequired = getRandomInt(2, 4);
     return {
@@ -1944,22 +1944,22 @@ export const giveNemesisPetRecipe = (inventory: TInventoryDatabaseDocument, neme
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartHeadA",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartHeadB",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartHeadC"
-    ]);
+    ])!;
     const body = getRandomElement([
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartBodyA",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartBodyB",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartBodyC"
-    ]);
+    ])!;
     const legs = getRandomElement([
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartLegsA",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartLegsB",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartLegsC"
-    ]);
+    ])!;
     const tail = getRandomElement([
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartTailA",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartTailB",
         "/Lotus/Types/Friendly/Pets/ZanukaPets/ZanukaPetParts/ZanukaPetPartTailC"
-    ]);
+    ])!;
     const recipeType = Object.entries(ExportRecipes).find(arr => arr[1].resultType == head)![0];
     addRecipes(inventory, [
         {

src/services/loginRewardService.ts

@@ -102,7 +102,7 @@ const getRandomLoginReward = (rng: CRng, day: number, inventory: TInventoryDatab
             // This account has all applicable warframes and weapons already mastered (filthy cheater), need a different reward.
             return getRandomLoginReward(rng, day, inventory);
         }
-        reward.StoreItemType = toStoreItem(rng.randomElement(eligibleRecipes));
+        reward.StoreItemType = toStoreItem(rng.randomElement(eligibleRecipes)!);
     }
     return {
         //_id: toOid(new Types.ObjectId()),

src/services/missionInventoryUpdateService.ts

@@ -930,7 +930,7 @@ export const addMissionRewards = async (
 
     if (rewardInfo.useVaultManifest) {
         MissionRewards.push({
-            StoreItem: getRandomElement(corruptedMods),
+            StoreItem: getRandomElement(corruptedMods)!,
             ItemCount: 1
         });
     }

src/services/personalRoomsService.ts

@@ -47,12 +47,12 @@ export const createGarden = (): IGardeningDatabase => {
                 Name: "Garden0",
                 Plants: [
                     {
-                        PlantType: getRandomElement(plantTypes),
+                        PlantType: getRandomElement(plantTypes)!,
                         EndTime: endTime,
                         PlotIndex: 0
                     },
                     {
-                        PlantType: getRandomElement(plantTypes),
+                        PlantType: getRandomElement(plantTypes)!,
                         EndTime: endTime,
                         PlotIndex: 1
                     }
@@ -62,12 +62,12 @@ export const createGarden = (): IGardeningDatabase => {
                 Name: "Garden1",
                 Plants: [
                     {
-                        PlantType: getRandomElement(plantTypes),
+                        PlantType: getRandomElement(plantTypes)!,
                         EndTime: endTime,
                         PlotIndex: 0
                     },
                     {
-                        PlantType: getRandomElement(plantTypes),
+                        PlantType: getRandomElement(plantTypes)!,
                         EndTime: endTime,
                         PlotIndex: 1
                     }
@@ -77,12 +77,12 @@ export const createGarden = (): IGardeningDatabase => {
                 Name: "Garden2",
                 Plants: [
                     {
-                        PlantType: getRandomElement(plantTypes),
+                        PlantType: getRandomElement(plantTypes)!,
                         EndTime: endTime,
                         PlotIndex: 0
                     },
                     {
-                        PlantType: getRandomElement(plantTypes),
+                        PlantType: getRandomElement(plantTypes)!,
                         EndTime: endTime,
                         PlotIndex: 1
                     }

src/services/rngService.ts

@@ -6,7 +6,7 @@ export interface IRngResult {
     probability: number;
 }
 
-export const getRandomElement = <T>(arr: T[]): T => {
+export const getRandomElement = <T>(arr: T[]): T | undefined => {
     return arr[Math.floor(Math.random() * arr.length)];
 };
 
@@ -113,7 +113,7 @@ export class CRng {
         return min;
     }
 
-    randomElement<T>(arr: T[]): T {
+    randomElement<T>(arr: T[]): T | undefined {
         return arr[Math.floor(this.random() * arr.length)];
     }
 
@@ -145,7 +145,7 @@ export class SRng {
         return min;
     }
 
-    randomElement<T>(arr: T[]): T {
+    randomElement<T>(arr: T[]): T | undefined {
         return arr[this.randomInt(0, arr.length - 1)];
     }
 

src/services/serversideVendorsService.ts

@@ -212,7 +212,7 @@ const generateVendorManifest = (vendorInfo: IGeneratableVendorInfo): IVendorMani
             while (processed.ItemManifest.length + offersToAdd.length < numItemsTarget) {
                 // TODO: Consider per-bin item limits
                 // TODO: Consider item probability weightings
-                offersToAdd.push(rng.randomElement(manifest.items));
+                offersToAdd.push(rng.randomElement(manifest.items)!);
             }
         } else {
             let binThisCycle;
@@ -256,7 +256,7 @@ const generateVendorManifest = (vendorInfo: IGeneratableVendorInfo): IVendorMani
                 for (let i = 0; i != rawItem.numRandomItemPrices; ++i) {
                     let itemPrice: { type: string; count: IRange };
                     do {
-                        itemPrice = rng.randomElement(manifest.randomItemPricesPerBin![rawItem.bin]);
+                        itemPrice = rng.randomElement(manifest.randomItemPricesPerBin![rawItem.bin])!;
                     } while (item.ItemPrices.find(x => x.ItemType == itemPrice.type));
                     item.ItemPrices.push({
                         ItemType: itemPrice.type,

src/services/worldStateService.ts

@@ -225,7 +225,7 @@ const pushSortieIfRelevant = (worldState: IWorldState, day: number): void => {
     const seed = new CRng(day).randomInt(0, 0xffff);
     const rng = new CRng(seed);
 
-    const boss = rng.randomElement(sortieBosses);
+    const boss = rng.randomElement(sortieBosses)!;
 
     const modifiers = [
         "SORTIE_MODIFIER_LOW_ENERGY",
@@ -302,7 +302,7 @@ const pushSortieIfRelevant = (worldState: IWorldState, day: number): void => {
 
             missionIndex = ExportRegions[node].missionIndex;
             if (missionIndex != 28) {
-                missionIndex = rng.randomElement(availableMissionIndexes);
+                missionIndex = rng.randomElement(availableMissionIndexes)!;
             }
         } while (
             specialMissionTypes.indexOf(missionIndex) != -1 &&
@@ -312,7 +312,7 @@ const pushSortieIfRelevant = (worldState: IWorldState, day: number): void => {
 
         if (i == 2 && rng.randomInt(0, 2) == 2) {
             const filteredModifiers = modifiers.filter(mod => mod !== "SORTIE_MODIFIER_MELEE_ONLY");
-            const modifierType = rng.randomElement(filteredModifiers);
+            const modifierType = rng.randomElement(filteredModifiers)!;
 
             if (boss == "SORTIE_BOSS_PHORID") {
                 selectedNodes.push({
@@ -346,7 +346,7 @@ const pushSortieIfRelevant = (worldState: IWorldState, day: number): void => {
                 ? modifiers.filter(mod => mod != "SORTIE_MODIFIER_HAZARD_RADIATION")
                 : modifiers;
 
-        const modifierType = rng.randomElement(filteredModifiers);
+        const modifierType = rng.randomElement(filteredModifiers)!;
 
         selectedNodes.push({
             missionType,
@@ -389,7 +389,7 @@ const getSeasonDailyChallenge = (day: number): ISeasonChallenge => {
         Daily: true,
         Activation: { $date: { $numberLong: dayStart.toString() } },
         Expiry: { $date: { $numberLong: dayEnd.toString() } },
-        Challenge: rng.randomElement(dailyChallenges)
+        Challenge: rng.randomElement(dailyChallenges)!
     };
 };
 
@@ -408,7 +408,7 @@ const getSeasonWeeklyChallenge = (week: number, id: number): ISeasonChallenge =>
         _id: { $oid: "67e1bb2d9d00cb47" + challengeId.toString().padStart(8, "0") },
         Activation: { $date: { $numberLong: weekStart.toString() } },
         Expiry: { $date: { $numberLong: weekEnd.toString() } },
-        Challenge: rng.randomElement(weeklyChallenges)
+        Challenge: rng.randomElement(weeklyChallenges)!
     };
 };
 
@@ -425,7 +425,7 @@ const getSeasonWeeklyHardChallenge = (week: number, id: number): ISeasonChalleng
         _id: { $oid: "67e1bb2d9d00cb47" + challengeId.toString().padStart(8, "0") },
         Activation: { $date: { $numberLong: weekStart.toString() } },
         Expiry: { $date: { $numberLong: weekEnd.toString() } },
-        Challenge: rng.randomElement(weeklyHardChallenges)
+        Challenge: rng.randomElement(weeklyHardChallenges)!
     };
 };
 
@@ -1196,7 +1196,7 @@ export const getLiteSortie = (week: number): ILiteSortie => {
                     "MT_EXTERMINATION",
                     "MT_SABOTAGE",
                     "MT_RESCUE"
-                ]),
+                ])!,
                 node: firstNode
             },
             {
@@ -1206,8 +1206,8 @@ export const getLiteSortie = (week: number): ILiteSortie => {
                     "MT_ARTIFACT",
                     "MT_EXCAVATE",
                     "MT_SURVIVAL"
-                ]),
+                ])!,
-                node: rng.randomElement(nodes)
+                node: rng.randomElement(nodes)!
             },
             {
                 missionType: "MT_ASSASSINATION",