diff --git a/src/Augmentation/ui/PurchaseAugmentationModal.tsx b/src/Augmentation/ui/PurchaseAugmentationModal.tsx
index e1c0c6a13..9b1d39533 100644
--- a/src/Augmentation/ui/PurchaseAugmentationModal.tsx
+++ b/src/Augmentation/ui/PurchaseAugmentationModal.tsx
@@ -40,7 +40,7 @@ export function PurchaseAugmentationModal({ aug, faction, onClose, open }: IProp
       <Button
         autoFocus
         onClick={() => {
-          purchaseAugmentation(aug, faction);
+          purchaseAugmentation(faction, aug);
           onClose();
         }}
       >
diff --git a/src/Faction/FactionHelpers.tsx b/src/Faction/FactionHelpers.tsx
index b4efcbffd..dd1ea0d0a 100644
--- a/src/Faction/FactionHelpers.tsx
+++ b/src/Faction/FactionHelpers.tsx
@@ -20,6 +20,7 @@ import { SFC32RNG } from "../Casino/RNG";
 import { isFactionWork } from "../Work/FactionWork";
 import { getAugCost } from "../Augmentation/AugmentationHelpers";
 import { getRecordKeys } from "../Types/Record";
+import type { Result } from "../types";
 
 export function inviteToFaction(faction: Faction): void {
   if (faction.alreadyInvited || faction.isMember) return;
@@ -58,52 +59,76 @@ export function hasAugmentationPrereqs(aug: Augmentation): boolean {
   return aug.prereqs.every((aug) => Player.hasAugmentation(aug));
 }
 
-export function purchaseAugmentation(aug: Augmentation, fac: Faction, sing = false): string {
-  const hasPrereqs = hasAugmentationPrereqs(aug);
-  const augCosts = getAugCost(aug);
-  if (!hasPrereqs) {
-    const txt = `You must first purchase or install ${aug.prereqs
-      .filter((req) => !Player.hasAugmentation(req))
-      .join(",")} before you can purchase this one.`;
-    if (sing) {
-      return txt;
-    } else {
-      dialogBoxCreate(txt);
-    }
-  } else if (augCosts.moneyCost !== 0 && Player.money < augCosts.moneyCost) {
-    const txt = "You don't have enough money to purchase " + aug.name;
-    if (sing) {
-      return txt;
-    }
-    dialogBoxCreate(txt);
-  } else if (fac.playerReputation < augCosts.repCost) {
-    const txt = "You don't have enough faction reputation to purchase " + aug.name;
-    if (sing) {
-      return txt;
-    }
-    dialogBoxCreate(txt);
-  } else if (augCosts.moneyCost === 0 || Player.money >= augCosts.moneyCost) {
-    Player.queueAugmentation(aug.name);
+function checkIfPlayerCanPurchaseAugmentation(faction: Faction, augmentation: Augmentation): Result {
+  if (!Player.factions.includes(faction.name)) {
+    return {
+      success: false,
+      message: `You can't purchase augmentations from '${faction.name}' because you aren't a member.`,
+    };
+  }
 
-    Player.loseMoney(augCosts.moneyCost, "augmentations");
+  if (!getFactionAugmentationsFiltered(faction).includes(augmentation.name)) {
+    return {
+      success: false,
+      message: `Faction '${faction.name}' does not have the '${augmentation.name}' augmentation.`,
+    };
+  }
 
-    if (sing) {
-      return "You purchased " + aug.name;
-    } else if (!Settings.SuppressBuyAugmentationConfirmation) {
-      dialogBoxCreate(
-        `You purchased ${aug.name}. Its enhancements will not take effect until they are installed. ` +
-          "To install your augmentations, go to the 'Augmentations' tab on the left-hand navigation menu. " +
-          "Purchasing additional augmentations will now be more expensive.",
-      );
+  if (augmentation.name !== AugmentationName.NeuroFluxGovernor) {
+    for (const queuedAugmentation of Player.queuedAugmentations) {
+      if (queuedAugmentation.name === augmentation.name) {
+        return { success: false, message: `You already purchased the '${augmentation.name}' augmentation.` };
+      }
     }
-  } else {
+    for (const installedAugmentation of Player.augmentations) {
+      if (installedAugmentation.name === augmentation.name) {
+        return { success: false, message: `You already installed the '${augmentation.name}' augmentation.` };
+      }
+    }
+  }
+
+  if (!hasAugmentationPrereqs(augmentation)) {
+    return {
+      success: false,
+      message: `You must first purchase or install ${augmentation.prereqs
+        .filter((req) => !Player.hasAugmentation(req))
+        .join(",")} before you can purchase this one.`,
+    };
+  }
+
+  const augCosts = getAugCost(augmentation);
+  if (augCosts.moneyCost !== 0 && Player.money < augCosts.moneyCost) {
+    return { success: false, message: `You don't have enough money to purchase ${augmentation.name}.` };
+  }
+
+  if (faction.playerReputation < augCosts.repCost) {
+    return { success: false, message: `You don't have enough faction reputation to purchase ${augmentation.name}.` };
+  }
+
+  return { success: true };
+}
+
+export function purchaseAugmentation(faction: Faction, augmentation: Augmentation, singularity = false): Result {
+  const result = checkIfPlayerCanPurchaseAugmentation(faction, augmentation);
+  if (!result.success) {
+    if (!singularity) {
+      dialogBoxCreate(result.message);
+    }
+    return { success: false, message: result.message };
+  }
+
+  const augCosts = getAugCost(augmentation);
+  Player.queueAugmentation(augmentation.name);
+  Player.loseMoney(augCosts.moneyCost, "augmentations");
+
+  if (!singularity && !Settings.SuppressBuyAugmentationConfirmation) {
     dialogBoxCreate(
-      "Hmm, something went wrong when trying to purchase an Augmentation. " +
-        "Please report this to the game developer with an explanation of how to " +
-        "reproduce this.",
+      `You purchased ${augmentation.name}. Its enhancements will not take effect until they are installed. ` +
+        "To install your augmentations, go to the 'Augmentations' tab on the left-hand navigation menu. " +
+        "Purchasing additional augmentations will now be more expensive.",
     );
   }
-  return "";
+  return { success: true };
 }
 
 export function processPassiveFactionRepGain(numCycles: number): void {
diff --git a/src/Faction/ui/AugmentationsPage.tsx b/src/Faction/ui/AugmentationsPage.tsx
index 6ba727a25..5d44bac1b 100644
--- a/src/Faction/ui/AugmentationsPage.tsx
+++ b/src/Faction/ui/AugmentationsPage.tsx
@@ -250,7 +250,7 @@ export function AugmentationsPage({ faction }: { faction: Faction }): React.Reac
           if (!Settings.SuppressBuyAugmentationConfirmation) {
             showModal(true);
           } else {
-            purchaseAugmentation(aug, faction);
+            purchaseAugmentation(faction, aug);
             rerender();
           }
         }}
diff --git a/src/NetscriptFunctions/Singularity.ts b/src/NetscriptFunctions/Singularity.ts
index 3f1dda057..276606993 100644
--- a/src/NetscriptFunctions/Singularity.ts
+++ b/src/NetscriptFunctions/Singularity.ts
@@ -1,7 +1,7 @@
 import type { Singularity as ISingularity } from "@nsdefs";
 
 import { Player } from "@player";
-import { AugmentationName, CityName, FactionWorkType, GymType, LocationName, UniversityClassType } from "@enums";
+import { CityName, FactionWorkType, GymType, LocationName, UniversityClassType } from "@enums";
 import { purchaseAugmentation, joinFaction, getFactionAugmentationsFiltered } from "../Faction/FactionHelpers";
 import { startWorkerScript } from "../NetscriptWorker";
 import { Augmentations } from "../Augmentation/Augmentations";
@@ -163,50 +163,17 @@ export function NetscriptSingularity(): InternalAPI<ISingularity> {
       helpers.checkSingularityAccess(ctx);
       const facName = getEnumHelper("FactionName").nsGetMember(ctx, _facName);
       const augName = getEnumHelper("AugmentationName").nsGetMember(ctx, _augName);
-      const fac = Factions[facName];
-      const aug = Augmentations[augName];
+      const faction = Factions[facName];
+      const augmentation = Augmentations[augName];
 
-      const factionAugs = getFactionAugmentationsFiltered(fac);
-
-      if (!Player.factions.includes(facName)) {
-        helpers.log(ctx, () => `You can't purchase augmentations from '${facName}' because you aren't a member`);
-        return false;
-      }
-
-      if (!factionAugs.includes(augName)) {
-        helpers.log(ctx, () => `Faction '${facName}' does not have the '${augName}' augmentation.`);
-        return false;
-      }
-
-      const isNeuroflux = aug.name === AugmentationName.NeuroFluxGovernor;
-      if (!isNeuroflux) {
-        for (let j = 0; j < Player.queuedAugmentations.length; ++j) {
-          if (Player.queuedAugmentations[j].name === aug.name) {
-            helpers.log(ctx, () => `You already have the '${augName}' augmentation.`);
-            return false;
-          }
-        }
-        for (let j = 0; j < Player.augmentations.length; ++j) {
-          if (Player.augmentations[j].name === aug.name) {
-            helpers.log(ctx, () => `You already have the '${augName}' augmentation.`);
-            return false;
-          }
-        }
-      }
-
-      if (fac.playerReputation < getAugCost(aug).repCost) {
-        helpers.log(ctx, () => `You do not have enough reputation with '${fac.name}'.`);
-        return false;
-      }
-
-      const res = purchaseAugmentation(aug, fac, true);
-      helpers.log(ctx, () => res);
-      if (res.startsWith("You purchased")) {
-        Player.gainIntelligenceExp(CONSTANTS.IntelligenceSingFnBaseExpGain * 10);
-        return true;
-      } else {
+      const result = purchaseAugmentation(faction, augmentation, true);
+      if (!result.success) {
+        helpers.log(ctx, () => result.message);
         return false;
       }
+      helpers.log(ctx, () => `You purchased ${augName}.`);
+      Player.gainIntelligenceExp(CONSTANTS.IntelligenceSingFnBaseExpGain * 10);
+      return true;
     },
     softReset: (ctx) => (_cbScript) => {
       helpers.checkSingularityAccess(ctx);
diff --git a/test/jest/Netscript/Singularity.test.ts b/test/jest/Netscript/Singularity.test.ts
index ee36c846a..cb1b65b53 100644
--- a/test/jest/Netscript/Singularity.test.ts
+++ b/test/jest/Netscript/Singularity.test.ts
@@ -1,9 +1,12 @@
 import { installAugmentations } from "../../../src/Augmentation/AugmentationHelpers";
 import { blackOpsArray } from "../../../src/Bladeburner/data/BlackOperations";
-import { AugmentationName } from "../../../src/Enums";
-import { Player } from "../../../src/Player";
+import { AugmentationName, FactionName } from "@enums";
+import { Player } from "@player";
+import { prestigeSourceFile } from "../../../src/Prestige";
 import { GetServerOrThrow } from "../../../src/Server/AllServers";
 import { SpecialServers } from "../../../src/Server/data/SpecialServers";
+import { Factions } from "../../../src/Faction/Factions";
+import { PlayerOwnedAugmentation } from "../../../src/Augmentation/PlayerOwnedAugmentation";
 import { getNS, initGameEnvironment, setupBasicTestingEnvironment } from "./Utilities";
 
 function setNumBlackOpsComplete(value: number): void {
@@ -179,3 +182,118 @@ describe("destroyW0r1dD43m0n", () => {
     });
   });
 });
+
+describe("purchaseAugmentation", () => {
+  beforeEach(() => {
+    setupBasicTestingEnvironment();
+    prestigeSourceFile(true);
+    Player.money = 1e100;
+    Player.factions.push(FactionName.CyberSec);
+    Factions[FactionName.CyberSec].playerReputation = 1e10;
+    Player.factions.push(FactionName.Illuminati);
+  });
+
+  describe("Success", () => {
+    const expectQueuedAugmentation = (augmentationName: AugmentationName, level: number) => {
+      expect(
+        Player.queuedAugmentations.find((augmentation) => augmentation.name === augmentationName)?.level,
+      ).toStrictEqual(level);
+    };
+    test("NFG", () => {
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.NeuroFluxGovernor),
+      ).toStrictEqual(true);
+      expectQueuedAugmentation(AugmentationName.NeuroFluxGovernor, 1);
+    });
+    // Check if the level of NFG is increased properly.
+    test("Upgrade NFG", () => {
+      Player.augmentations.push(new PlayerOwnedAugmentation(AugmentationName.NeuroFluxGovernor));
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.NeuroFluxGovernor),
+      ).toStrictEqual(true);
+      expectQueuedAugmentation(AugmentationName.NeuroFluxGovernor, 2);
+    });
+    test("Normal augmentation", () => {
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.CranialSignalProcessorsG1),
+      ).toStrictEqual(true);
+      expectQueuedAugmentation(AugmentationName.CranialSignalProcessorsG1, 1);
+    });
+    test("Normal augmentation with prerequisite", () => {
+      Player.augmentations.push(new PlayerOwnedAugmentation(AugmentationName.CranialSignalProcessorsG1));
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.CranialSignalProcessorsG2),
+      ).toStrictEqual(true);
+      expectQueuedAugmentation(AugmentationName.CranialSignalProcessorsG2, 1);
+    });
+    test("Buy 0-money-cost augmentation with negative money", () => {
+      Player.money = -1000;
+      Player.factions.push(FactionName.Daedalus);
+      Factions[FactionName.Daedalus].playerReputation = 1e10;
+      const ns = getNS();
+      expect(ns.singularity.purchaseAugmentation(FactionName.Daedalus, AugmentationName.TheRedPill)).toStrictEqual(
+        true,
+      );
+      expectQueuedAugmentation(AugmentationName.TheRedPill, 1);
+    });
+  });
+
+  describe("Failure", () => {
+    const expectNoQueuedAugmentation = (augmentationName: AugmentationName) => {
+      expect(Player.queuedAugmentations.find((augmentation) => augmentation.name === augmentationName)).toStrictEqual(
+        undefined,
+      );
+    };
+    test("Not a member of specified faction", () => {
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.Daedalus, AugmentationName.NeuroFluxGovernor),
+      ).toStrictEqual(false);
+      expectNoQueuedAugmentation(AugmentationName.NeuroFluxGovernor);
+    });
+    test("Faction does not have specified augmentation", () => {
+      const ns = getNS();
+      expect(ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.QLink)).toStrictEqual(false);
+      expectNoQueuedAugmentation(AugmentationName.QLink);
+    });
+    test("Purchase installed augmentation", () => {
+      Player.augmentations.push(new PlayerOwnedAugmentation(AugmentationName.CranialSignalProcessorsG1));
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.CranialSignalProcessorsG1),
+      ).toStrictEqual(false);
+      expectNoQueuedAugmentation(AugmentationName.CranialSignalProcessorsG1);
+    });
+    test("Purchase queued augmentation", () => {
+      Player.queuedAugmentations.push(new PlayerOwnedAugmentation(AugmentationName.CranialSignalProcessorsG1));
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.CranialSignalProcessorsG1),
+      ).toStrictEqual(false);
+    });
+    test("Not have prerequisite augmentation", () => {
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.CranialSignalProcessorsG2),
+      ).toStrictEqual(false);
+      expectNoQueuedAugmentation(AugmentationName.CranialSignalProcessorsG2);
+    });
+    test("Not enough money", () => {
+      Player.money = 1000;
+      const ns = getNS();
+      expect(
+        ns.singularity.purchaseAugmentation(FactionName.CyberSec, AugmentationName.CranialSignalProcessorsG1),
+      ).toStrictEqual(false);
+      expectNoQueuedAugmentation(AugmentationName.CranialSignalProcessorsG1);
+    });
+    test("Not enough reputation", () => {
+      const ns = getNS();
+      expect(ns.singularity.purchaseAugmentation(FactionName.Illuminati, AugmentationName.QLink)).toStrictEqual(false);
+      expectNoQueuedAugmentation(AugmentationName.QLink);
+    });
+  });
+});