feat: add admin /logs command to view bot log lines

Signed-off-by: Michael Cramer <michael@bigmichi1.de>

Author: BigMichi1

src/bot/bot.ts

@@ -18,6 +18,7 @@ import { buildCodesPage } from './commands/codes';
 import * as autoredeemCommand from './commands/autoredeem';
 import * as helpCommand from './commands/help';
 import * as inventoryCommand from './commands/inventory';
+import * as logsCommand from './commands/logs';
 import * as makepublicCommand from './commands/makepublic';
 import * as notificationsCommand from './commands/notifications';
 import * as openCommand from './commands/open';
@@ -61,6 +62,7 @@ const commands = [
   deleteaccountCommand,
   helpCommand,
   inventoryCommand,
+  logsCommand,
   makepublicCommand,
   notificationsCommand,
   openCommand,

src/bot/commands/help.ts

@@ -76,6 +76,11 @@ export async function execute(interaction: ChatInputCommandInteraction) {
           value: '`/backfill [channel:<channel>]`\nRecover missed codes from message history (admin only).',
           inline: false,
         },
+        {
+          name: '📋 Logs',
+          value: '`/logs [lines:<n>]`\nShow the last N lines of the bot log (admin only, default 20, max 100).',
+          inline: false,
+        },
         {
           name: '🗑️ Delete Account',
           value:

src/bot/commands/logs.test.ts

@@ -0,0 +1,272 @@
+import { describe, test, expect, beforeEach, afterEach, spyOn } from 'bun:test';
+import { MessageFlags } from 'discord.js';
+import fs from 'fs';
+import { execute } from './logs';
+
+// ---------------------------------------------------------------------------
+// Interaction mock helpers
+// ---------------------------------------------------------------------------
+
+function makeInteraction(opts: { hasPermission?: boolean; lines?: number | null } = {}) {
+  const { hasPermission = true, lines = null } = opts;
+
+  const editReplySpy = spyOn({ editReply: async (_: unknown) => {} }, 'editReply');
+  const replySpy = spyOn({ reply: async (_: unknown) => {} }, 'reply');
+
+  const interaction = {
+    user: { id: 'admin-1', tag: 'admin#0001' },
+    deferred: false,
+    replied: false,
+    memberPermissions: hasPermission ? { has: () => true } : null,
+    deferReply: async () => {
+      (interaction as any).deferred = true;
+    },
+    editReply: editReplySpy,
+    reply: replySpy,
+    options: {
+      getInteger: (name: string) => (name === 'lines' ? lines : null),
+    },
+  } as any;
+
+  return { interaction, editReplySpy, replySpy };
+}
+
+// Sample log lines used across multiple tests
+const SAMPLE_LINES = Array.from(
+  { length: 50 },
+  (_, i) => `2026-05-24 12:00:${String(i).padStart(2, '0')} [INFO]: Log message ${i}`
+);
+const SAMPLE_CONTENT = SAMPLE_LINES.join('\n');
+
+// ---------------------------------------------------------------------------
+// Permission denied
+// ---------------------------------------------------------------------------
+
+describe('/logs – permission denied', () => {
+  test('replies ephemerally with "Permission Denied" when user lacks ManageMessages', async () => {
+    const { interaction, replySpy } = makeInteraction({ hasPermission: false });
+
+    await execute(interaction);
+
+    expect(replySpy).toHaveBeenCalledTimes(1);
+    const reply = replySpy.mock.calls[0]![0] as any;
+    expect(reply.embeds[0].data.title).toContain('Permission Denied');
+    expect(reply.flags).toBe(MessageFlags.Ephemeral);
+    expect(interaction.deferred).toBe(false);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Log file missing
+// ---------------------------------------------------------------------------
+
+describe('/logs – log file missing', () => {
+  let existsSpy: ReturnType<typeof spyOn>;
+
+  beforeEach(() => {
+    existsSpy = spyOn(fs, 'existsSync').mockReturnValue(false);
+  });
+
+  afterEach(() => {
+    existsSpy.mockRestore();
+  });
+
+  test('defers reply and shows "No log entries found" when combined.log does not exist', async () => {
+    const { interaction, editReplySpy } = makeInteraction();
+
+    await execute(interaction);
+
+    expect(interaction.deferred).toBe(true);
+    expect(editReplySpy).toHaveBeenCalledTimes(1);
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.description).toContain('No log entries found');
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Reading log lines
+// ---------------------------------------------------------------------------
+
+describe('/logs – reading log lines', () => {
+  let existsSpy: ReturnType<typeof spyOn>;
+  let readSpy: ReturnType<typeof spyOn>;
+
+  beforeEach(() => {
+    existsSpy = spyOn(fs, 'existsSync').mockReturnValue(true);
+    readSpy = spyOn(fs, 'readFileSync').mockReturnValue(SAMPLE_CONTENT);
+  });
+
+  afterEach(() => {
+    existsSpy.mockRestore();
+    readSpy.mockRestore();
+  });
+
+  test('defers reply', async () => {
+    const { interaction } = makeInteraction({ lines: 5 });
+
+    await execute(interaction);
+
+    expect(interaction.deferred).toBe(true);
+  });
+
+  test('defaults to 20 lines when no lines param is provided', async () => {
+    const { interaction, editReplySpy } = makeInteraction({ lines: null });
+
+    await execute(interaction);
+
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.title).toContain('last 20 lines');
+    const lastTwenty = SAMPLE_LINES.slice(-20);
+    expect(embed.description).toContain(lastTwenty[0]);
+    expect(embed.description).toContain(lastTwenty[19]);
+  });
+
+  test('respects custom lines parameter', async () => {
+    const { interaction, editReplySpy } = makeInteraction({ lines: 5 });
+
+    await execute(interaction);
+
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.title).toContain('last 5 lines');
+    const lastFive = SAMPLE_LINES.slice(-5);
+    for (const line of lastFive) {
+      expect(embed.description).toContain(line);
+    }
+    // Lines outside the requested range must not appear
+    expect(embed.description).not.toContain(SAMPLE_LINES[0]);
+  });
+
+  test('wraps output in a code block', async () => {
+    const { interaction, editReplySpy } = makeInteraction({ lines: 3 });
+
+    await execute(interaction);
+
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.description).toMatch(/^```\n/);
+    expect(embed.description).toMatch(/\n```$/);
+  });
+
+  test('title includes the actual number of lines returned', async () => {
+    const { interaction, editReplySpy } = makeInteraction({ lines: 10 });
+
+    await execute(interaction);
+
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.title).toContain('10 lines');
+  });
+
+  test('redacts sensitive credential fields from log lines', async () => {
+    const sensitiveContent = [
+      '2026-05-24 12:00:01 [INFO]: [CMD] admin#0001 used /setup: user_id=123456 user_hash=supersecret',
+      '2026-05-24 12:00:02 [INFO]: [CMD] admin#0001 used /redeem: code=ABC-123',
+      '2026-05-24 12:00:03 [INFO]: token=mytoken hash=myhash normal log line',
+    ].join('\n');
+
+    readSpy.mockReturnValue(sensitiveContent);
+    const { interaction, editReplySpy } = makeInteraction({ lines: 10 });
+
+    await execute(interaction);
+
+    const desc = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data.description;
+    expect(desc).not.toContain('supersecret');
+    expect(desc).not.toContain('mytoken');
+    expect(desc).not.toContain('myhash');
+    expect(desc).toContain('user_hash=[REDACTED]');
+    expect(desc).toContain('user_id=[REDACTED]');
+    expect(desc).toContain('token=[REDACTED]');
+    expect(desc).toContain('hash=[REDACTED]');
+    // Non-sensitive fields must not be redacted
+    expect(desc).toContain('code=ABC-123');
+  });
+
+  test('escapes triple-backticks in log content to prevent breaking the code block', async () => {
+    const contentWithBackticks = '2026-05-24 12:00:01 [INFO]: line with ```backticks``` inside';
+    readSpy.mockReturnValue(contentWithBackticks);
+    const { interaction, editReplySpy } = makeInteraction({ lines: 5 });
+
+    await execute(interaction);
+
+    const desc = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data.description;
+    // The injected triple-backticks must be replaced
+    expect(desc).toContain("'''backticks'''");
+    // Overall structure must still be a valid code block
+    expect(desc).toMatch(/^```\n/);
+    expect(desc).toMatch(/\n```$/);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Truncation
+// ---------------------------------------------------------------------------
+
+describe('/logs – truncation', () => {
+  let existsSpy: ReturnType<typeof spyOn>;
+  let readSpy: ReturnType<typeof spyOn>;
+
+  // Build a log whose content far exceeds the 4096-char embed limit
+  const bigLine = 'X'.repeat(80);
+  const bigLines = Array.from({ length: 100 }, (_, i) => `${bigLine} line-${i}`);
+  const bigContent = bigLines.join('\n');
+
+  beforeEach(() => {
+    existsSpy = spyOn(fs, 'existsSync').mockReturnValue(true);
+    readSpy = spyOn(fs, 'readFileSync').mockReturnValue(bigContent);
+  });
+
+  afterEach(() => {
+    existsSpy.mockRestore();
+    readSpy.mockRestore();
+  });
+
+  test('embed description stays within the 4096-char limit', async () => {
+    const { interaction, editReplySpy } = makeInteraction({ lines: 100 });
+
+    await execute(interaction);
+
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.description.length).toBeLessThanOrEqual(4096);
+  });
+
+  test('title shows displayed vs requested line count when truncated', async () => {
+    const { interaction, editReplySpy } = makeInteraction({ lines: 100 });
+
+    await execute(interaction);
+
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.title).toContain('truncated');
+    // e.g. "showing 45 of 100 lines — truncated"
+    expect(embed.title).toMatch(/showing \d+ of 100 lines/);
+  });
+});
+
+// ---------------------------------------------------------------------------
+// Error handling
+// ---------------------------------------------------------------------------
+
+describe('/logs – error handling', () => {
+  let existsSpy: ReturnType<typeof spyOn>;
+  let readSpy: ReturnType<typeof spyOn>;
+
+  beforeEach(() => {
+    existsSpy = spyOn(fs, 'existsSync').mockReturnValue(true);
+    readSpy = spyOn(fs, 'readFileSync').mockImplementation(() => {
+      throw new Error('disk read error');
+    });
+  });
+
+  afterEach(() => {
+    existsSpy.mockRestore();
+    readSpy.mockRestore();
+  });
+
+  test('replies with error embed when log file cannot be read', async () => {
+    const { interaction, editReplySpy } = makeInteraction();
+
+    await execute(interaction);
+
+    expect(editReplySpy).toHaveBeenCalledTimes(1);
+    const embed = (editReplySpy.mock.calls[0]![0] as any).embeds[0].data;
+    expect(embed.title).toContain('Error');
+    expect(embed.description).toContain('Failed to read log file');
+  });
+});