my-pi/pi-compaction/test/native-compaction.test.ts

import test from "node:test";
import assert from "node:assert/strict";
import {
  buildReplacementHistory,
  findNativeCheckpoint,
  parseNativeCompactionDetails,
  type NativeCompactionDetails,
} from "../src/native-compaction.ts";

const details: NativeCompactionDetails = {
  kind: "pi-compaction",
  version: 1,
  checkpoint: "native",
  modelKey: "openai-codex/openai-codex-responses/gpt-test",
  replacementHistory: [{ type: "compaction", encrypted_content: "opaque" }],
  portableSummary: "portable",
  sourceFingerprint: "abc",
};

test("recognizes only the unified native checkpoint format", () => {
  assert.deepEqual(parseNativeCompactionDetails(details), details);
  assert.equal(parseNativeCompactionDetails({ ...details, kind: "openai-codex-native-compaction" }), undefined);
  assert.equal(parseNativeCompactionDetails({ ...details, portableSummary: undefined }), undefined);
});

test("latest Pi compaction entry is the authoritative native checkpoint", () => {
  const branch = [
    { type: "message", id: "m1" },
    { type: "compaction", id: "c1", details },
  ] as any;
  const found = findNativeCheckpoint(branch);
  assert.equal(found.status, "valid");
  if (found.status === "valid") assert.equal(found.checkpoint.entryIndex, 1);

  const shadowed = findNativeCheckpoint([...branch, { type: "compaction", id: "c2", details: { kind: "other" } }] as any);
  assert.equal(shadowed.status, "none");
  const portable = findNativeCheckpoint([
    ...branch,
    { type: "compaction", id: "c3", details: { kind: "pi-compaction", version: 1, checkpoint: "portable" } },
  ] as any);
  assert.equal(portable.status, "none");
});

test("replacement history ends with exactly one native item", () => {
  const history = buildReplacementHistory([
    { role: "user", content: [{ type: "input_text", text: "recent" }] },
  ], { type: "compaction", encrypted_content: "opaque" }, 1_000);
  assert.equal(history.at(-1)?.type, "compaction");
  assert.equal(history.filter((item) => item.type === "compaction").length, 1);
});