Inidivudal points

__tests__/simulation-impact-core.test.ts

@@ -0,0 +1,141 @@
+import { describe, expect, it } from "bun:test";
+import {
+  buildPrefixSums,
+  computeImpactContributions,
+} from "@/utils/simulation-impact";
+
+function buildWorldPoints(count: number) {
+  return Array.from({ length: count }, (_, index) => count - index);
+}
+
+describe("simulation impact core", () => {
+  it("keeps contribution at zero for pilots outside the current top half", () => {
+    const allPilots = Array.from({ length: 81 }, (_, index) => ({
+      key: `pilot-${index}`,
+      civlId: index + 1,
+    }));
+    const worldPoints = buildWorldPoints(200);
+    const rankedByCivlId = new Map(
+      worldPoints.map((points, index) => [index + 1, { points }]),
+    );
+    const topWorldPrefixSums = buildPrefixSums(worldPoints);
+    const selectedPilotKeys = allPilots.map((pilot) => pilot.key);
+
+    const impacts = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys,
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    expect((impacts["pilot-39"] ?? 0) > 0).toBe(true);
+    expect(impacts["pilot-40"]).toBe(0);
+    expect(impacts["pilot-60"]).toBe(0);
+  });
+
+  it("does not create lower-half contribution after deselecting a zero-contribution pilot", () => {
+    const allPilots = Array.from({ length: 81 }, (_, index) => ({
+      key: `pilot-${index}`,
+      civlId: index + 1,
+    }));
+    const worldPoints = buildWorldPoints(200);
+    const rankedByCivlId = new Map(
+      worldPoints.map((points, index) => [index + 1, { points }]),
+    );
+    const topWorldPrefixSums = buildPrefixSums(worldPoints);
+
+    const selectedPilotKeys = allPilots.map((pilot) => pilot.key);
+    const impactsWithAll = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys,
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    const impactsWithoutTail = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys: selectedPilotKeys.filter((key) => key !== "pilot-80"),
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    expect(impactsWithAll["pilot-60"]).toBe(0);
+    expect(impactsWithoutTail["pilot-60"]).toBe(0);
+  });
+
+  it("never returns negative displayed impact", () => {
+    const allPilots = Array.from({ length: 90 }, (_, index) => ({
+      key: `pilot-${index}`,
+      civlId: index % 3 === 0 ? undefined : index + 1,
+    }));
+    const worldPoints = buildWorldPoints(200);
+    const rankedByCivlId = new Map(
+      worldPoints.map((points, index) => [index + 1, { points }]),
+    );
+    const topWorldPrefixSums = buildPrefixSums(worldPoints);
+    const selectedPilotKeys = allPilots.map((pilot) => pilot.key);
+
+    const impacts = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys,
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    expect(Object.values(impacts).every((value) => value >= 0)).toBe(true);
+  });
+
+  it("returns positive would-add only for unselected pilots who can enter top half", () => {
+    const allPilots = Array.from({ length: 90 }, (_, index) => ({
+      key: `pilot-${index}`,
+      civlId: index + 1,
+    }));
+    const worldPoints = buildWorldPoints(300);
+    const rankedByCivlId = new Map(
+      worldPoints.map((points, index) => [index + 1, { points }]),
+    );
+    const topWorldPrefixSums = buildPrefixSums(worldPoints);
+    const selectedPilotKeys = allPilots.slice(5, 85).map((pilot) => pilot.key);
+
+    const impacts = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys,
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    expect((impacts["pilot-0"] ?? 0) > 0).toBe(true);
+    expect(impacts["pilot-89"]).toBe(0);
+  });
+
+  it("keeps would-add and selected impact aligned for the same pilot", () => {
+    const allPilots = Array.from({ length: 110 }, (_, index) => ({
+      key: `pilot-${index}`,
+      civlId: index + 1,
+    }));
+    const worldPoints = buildWorldPoints(300);
+    const rankedByCivlId = new Map(
+      worldPoints.map((points, index) => [index + 1, { points }]),
+    );
+    const topWorldPrefixSums = buildPrefixSums(worldPoints);
+    const selectedPilotKeys = allPilots.slice(20, 80).map((pilot) => pilot.key);
+    const pilotKey = "pilot-0";
+
+    const beforeAdd = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys,
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    const afterAdd = computeImpactContributions({
+      allPilots,
+      selectedPilotKeys: [...selectedPilotKeys, pilotKey],
+      rankedByCivlId,
+      topWorldPrefixSums,
+    });
+
+    expect((beforeAdd[pilotKey] ?? 0) > 0).toBe(true);
+    expect(afterAdd[pilotKey]).toBeCloseTo(beforeAdd[pilotKey] ?? 0, 12);
+  });
+});