session-viewer/tests/unit/session-metadata.test.ts

import { describe, it, expect } from "vitest";
import { extractSessionMetadata } from "../../src/server/services/session-metadata.js";
import { parseSessionContent } from "../../src/server/services/session-parser.js";
import fs from "fs/promises";
import path from "path";

describe("session-metadata", () => {
  it("messageCount matches parseSessionContent on sample-session.jsonl", async () => {
    const fixturePath = path.join(__dirname, "../fixtures/sample-session.jsonl");
    const content = await fs.readFile(fixturePath, "utf-8");

    const meta = extractSessionMetadata(content);
    const parsed = parseSessionContent(content);

    expect(meta.messageCount).toBe(parsed.length);
  });

  it("messageCount matches parseSessionContent on edge-cases.jsonl", async () => {
    const fixturePath = path.join(__dirname, "../fixtures/edge-cases.jsonl");
    const content = await fs.readFile(fixturePath, "utf-8");

    const meta = extractSessionMetadata(content);
    const parsed = parseSessionContent(content);

    expect(meta.messageCount).toBe(parsed.length);
  });

  it("firstPrompt skips system-reminder messages", () => {
    const content = [
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "<system-reminder>hook output</system-reminder>" },
        uuid: "u-sr",
        timestamp: "2025-01-01T00:00:00Z",
      }),
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "What is the project structure?" },
        uuid: "u-real",
        timestamp: "2025-01-01T00:00:01Z",
      }),
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.firstPrompt).toBe("What is the project structure?");
  });

  it("firstPrompt truncated to 200 chars", () => {
    const longMessage = "a".repeat(300);
    const content = JSON.stringify({
      type: "user",
      message: { role: "user", content: longMessage },
      uuid: "u-long",
      timestamp: "2025-01-01T00:00:00Z",
    });

    const meta = extractSessionMetadata(content);
    expect(meta.firstPrompt).toHaveLength(200);
    expect(meta.firstPrompt).toBe("a".repeat(200));
  });

  it("summary captures the LAST summary line", () => {
    const content = [
      JSON.stringify({ type: "summary", summary: "First summary", uuid: "s-1" }),
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "Hello" },
        uuid: "u-1",
      }),
      JSON.stringify({ type: "summary", summary: "Last summary", uuid: "s-2" }),
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.summary).toBe("Last summary");
  });

  it("timestamps captured from first and last lines with timestamps", () => {
    const content = [
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "Hello" },
        uuid: "u-1",
        timestamp: "2025-01-01T10:00:00Z",
      }),
      JSON.stringify({
        type: "assistant",
        message: { role: "assistant", content: "Hi" },
        uuid: "a-1",
        timestamp: "2025-01-01T10:05:00Z",
      }),
      JSON.stringify({
        type: "summary",
        summary: "Session done",
        uuid: "s-1",
      }),
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.firstTimestamp).toBe("2025-01-01T10:00:00Z");
    expect(meta.lastTimestamp).toBe("2025-01-01T10:05:00Z");
  });

  it("empty content returns zero counts and empty strings", () => {
    const meta = extractSessionMetadata("");
    expect(meta.messageCount).toBe(0);
    expect(meta.firstPrompt).toBe("");
    expect(meta.summary).toBe("");
    expect(meta.firstTimestamp).toBe("");
    expect(meta.lastTimestamp).toBe("");
    expect(meta.parseErrors).toBe(0);
  });

  it("JSONL with no user messages returns empty firstPrompt", () => {
    const content = [
      JSON.stringify({ type: "summary", summary: "No user", uuid: "s-1" }),
      JSON.stringify({ type: "progress", data: { type: "hook" }, uuid: "p-1" }),
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.firstPrompt).toBe("");
  });

  it("JSONL with all system-reminder users returns empty firstPrompt", () => {
    const content = [
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "<system-reminder>r1</system-reminder>" },
        uuid: "u-1",
      }),
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "<system-reminder>r2</system-reminder>" },
        uuid: "u-2",
      }),
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.firstPrompt).toBe("");
  });

  it("single-line JSONL: firstTimestamp equals lastTimestamp", () => {
    const content = JSON.stringify({
      type: "user",
      message: { role: "user", content: "solo" },
      uuid: "u-solo",
      timestamp: "2025-06-15T12:00:00Z",
    });

    const meta = extractSessionMetadata(content);
    expect(meta.firstTimestamp).toBe("2025-06-15T12:00:00Z");
    expect(meta.lastTimestamp).toBe("2025-06-15T12:00:00Z");
  });

  it("reports parseErrors from malformed lines", () => {
    const content = [
      "broken json",
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "ok" },
        uuid: "u-1",
      }),
      "{truncated",
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.parseErrors).toBe(2);
    expect(meta.messageCount).toBe(1);
  });

  it("skips array user content for firstPrompt (only captures string content)", () => {
    const content = [
      JSON.stringify({
        type: "user",
        message: {
          role: "user",
          content: [
            { type: "tool_result", tool_use_id: "t1", content: "result" },
          ],
        },
        uuid: "u-arr",
      }),
      JSON.stringify({
        type: "user",
        message: { role: "user", content: "Second prompt as string" },
        uuid: "u-str",
      }),
    ].join("\n");

    const meta = extractSessionMetadata(content);
    expect(meta.firstPrompt).toBe("Second prompt as string");
  });
});