import { describe, expect, it } from "@effect/vitest"; import {  decodeScanCache,  dedupeWithinFile,  encodeScanCache,  pruneScanCache,  type ScanCache,} from "./usageScanCache.ts";import type { UsageRecord } from "./usageTranscripts.ts"; function record(overrides: Partial<UsageRecord> = {}): UsageRecord {  return {    provider: "claude",    timestampMs: 1_786_000_000_000,    model: "claude-fable-5",    sessionId: "session-a",    totals: {      uncachedInputTokens: 2,      cachedInputTokens: 1000,      cacheCreationTokens: 10,      outputTokens: 50,      reasoningTokens: 0,    },    reportedCostUsd: null,    dedupeKey: "msg_1:",    ...overrides,  };} function cacheWith(entries: readonly [string, number, readonly UsageRecord[]][]): ScanCache {  const cache: ScanCache = new Map();  for (const [path, mtimeMs, records] of entries) {    cache.set(path, { size: records.length * 10, mtimeMs, provider: "claude", records });  }  return cache;} describe("scan cache round trip", () => {  it("restores records unchanged", () => {    const original = cacheWith([      ["/a.jsonl", 100, [record(), record({ dedupeKey: "msg_2:", model: "claude-opus-5" })]],      ["/b.jsonl", 200, [record({ sessionId: "session-b", reportedCostUsd: 1.5 })]],    ]);     const restored = decodeScanCache(JSON.parse(JSON.stringify(encodeScanCache(original))));     expect(restored.size).toBe(2);    expect(restored.get("/a.jsonl")).toEqual(original.get("/a.jsonl"));    expect(restored.get("/b.jsonl")).toEqual(original.get("/b.jsonl"));  });   it("interns repeated model and session strings", () => {    const encoded = encodeScanCache(      cacheWith([["/a.jsonl", 100, [record(), record({ dedupeKey: "msg_2:" }), record()]]]),    );     expect(encoded.models).toEqual(["claude-fable-5"]);    expect(encoded.sessions).toEqual(["session-a"]);  });   it("treats a corrupt or foreign document as an empty cache", () => {    // A bad cache should cost one cold scan, never a broken page.    expect(decodeScanCache(null).size).toBe(0);    expect(decodeScanCache("nonsense").size).toBe(0);    expect(decodeScanCache({ version: 999, models: [], sessions: [], files: {} }).size).toBe(0);  });   it("skips malformed file entries but keeps good ones", () => {    const encoded = encodeScanCache(cacheWith([["/good.jsonl", 100, [record()]]]));    const withJunk = {      ...encoded,      files: { ...encoded.files, "/bad.jsonl": { s: "nope", m: 1, p: "claude", r: [] } },    };     const restored = decodeScanCache(JSON.parse(JSON.stringify(withJunk)));    expect([...restored.keys()]).toEqual(["/good.jsonl"]);  });   it("rejects the whole cache when an intern table holds a non-string", () => {    // models: [1] would pass the undefined guard, put a number in a record's    // model, and crash normalizeModelName at aggregate time.    const encoded = encodeScanCache(cacheWith([["/a.jsonl", 100, [record()]]]));    const poisoned = { ...encoded, models: [1] };     expect(decodeScanCache(JSON.parse(JSON.stringify(poisoned))).size).toBe(0);  });   it("drops the whole entry when any row is corrupt, forcing a cold re-parse", () => {    // Keeping the surviving rows under the original (size, mtime) would read    // as a valid warm hit and the file would never be re-parsed.    const encoded = encodeScanCache(      cacheWith([["/a.jsonl", 100, [record(), record({ dedupeKey: "msg_2:" })]]]),    );    const rows = encoded.files["/a.jsonl"]!.r;    const poisoned = {      ...encoded,      files: {        "/a.jsonl": {          ...encoded.files["/a.jsonl"]!,          r: [rows[0]!, [...rows[1]!.slice(0, 3), "not-a-number", ...rows[1]!.slice(4)]],        },      },    };     const restored = decodeScanCache(JSON.parse(JSON.stringify(poisoned)));    expect(restored.has("/a.jsonl")).toBe(false);  });}); describe("pruneScanCache", () => {  const retentionCutoffMs = 1000;   it("drops entries older than retention", () => {    const cache = cacheWith([["/old.jsonl", 500, [record()]]]);     const removed = pruneScanCache(cache, {      livePaths: new Set(),      walkedRoots: ["/"],      windowStartMs: 400,      retentionCutoffMs,    });     expect(removed).toBe(1);    expect(cache.size).toBe(0);  });   it("drops in-window entries whose file has disappeared", () => {    const cache = cacheWith([["/gone.jsonl", 5000, [record()]]]);     pruneScanCache(cache, {      livePaths: new Set(),      walkedRoots: ["/"],      windowStartMs: 4000,      retentionCutoffMs,    });     expect(cache.size).toBe(0);  });   it("keeps entries outside the walked window that are still within retention", () => {    // Viewing 7 days must not evict the 30-day entries, which that walk never    // looked for and so cannot prove are gone.    const cache = cacheWith([["/older-but-valid.jsonl", 2000, [record()]]]);     const removed = pruneScanCache(cache, {      livePaths: new Set(),      walkedRoots: ["/"],      windowStartMs: 4000,      retentionCutoffMs,    });     expect(removed).toBe(0);    expect(cache.size).toBe(1);  });   it("keeps entries the walk saw", () => {    const cache = cacheWith([["/live.jsonl", 5000, [record()]]]);     pruneScanCache(cache, {      livePaths: new Set(["/live.jsonl"]),      walkedRoots: ["/"],      windowStartMs: 4000,      retentionCutoffMs,    });     expect(cache.size).toBe(1);  });}); describe("pruneScanCache with an unwalked root", () => {  it("keeps in-window entries for a provider whose directory was not walked", () => {    // A missing provider root or failed settings read leaves livePaths without    // that provider's files. Its warm entries must survive the pass.    const cache = cacheWith([["/codex/sessions/a.jsonl", 5000, [record()]]]);     const removed = pruneScanCache(cache, {      livePaths: new Set(),      walkedRoots: ["/claude/projects"],      windowStartMs: 4000,      retentionCutoffMs: 1000,    });     expect(removed).toBe(0);    expect(cache.size).toBe(1);  });}); describe("dedupeWithinFile", () => {  it("keeps the first record per dedupe key", () => {    const kept = dedupeWithinFile([      record({ totals: { ...record().totals, outputTokens: 1 } }),      record({ totals: { ...record().totals, outputTokens: 999 } }),      record({ dedupeKey: "msg_2:" }),    ]);     expect(kept).toHaveLength(2);    expect(kept[0]?.totals.outputTokens).toBe(1);  });   it("keeps every record that has no dedupe key", () => {    expect(      dedupeWithinFile([record({ dedupeKey: null }), record({ dedupeKey: null })]),    ).toHaveLength(2);  });});