chore: import upstream snapshot with attribution

tests/setup/env-isolation.ts

@@ -0,0 +1,111 @@
+// Vitest setup file: isolates every test from the developer's shell environment.
+//
+// codeburn discovers sessions through a long list of provider-specific env
+// vars (CLAUDE_CONFIG_DIR, CODEX_HOME, CRUSH_GLOBAL_DATA, …) and via HOME /
+// XDG_* / APPDATA / LOCALAPPDATA. Without this file, any value set in the
+// developer's shell (e.g. CLAUDE_CONFIG_DIRS=/Users/me/.claude:…) bleeds into
+// fixture-based tests: the parser reads the developer's REAL sessions instead
+// of the temp-dir fixture, producing nonsense totals and false failures that
+// pass on a clean CI runner.
+//
+// What this file does:
+//   1. Mints an empty sandbox temp dir once per worker.
+//   2. REDIRECTED vars (HOME / XDG_* / APPDATA / LOCALAPPDATA) point at the
+//      sandbox so any fallback to homedir() / platform defaults lands in an
+//      empty filesystem.
+//   3. CLEARED vars (every provider's explicit override) are deleted so a test
+//      that does NOT set one gets "unconfigured" rather than the dev's value.
+//   4. PRESERVED vars (PATH, COLUMNS, …) are snapshotted from the dev's shell
+//      and restored every test. We can't wipe them - Node uses PATH for spawn
+//      and module resolution, terminal code uses COLUMNS - but a test that
+//      mutates them shouldn't leak the change into the next test.
+//   5. Re-asserts the above before EVERY test (global beforeEach), so a test
+//      that mutates an env var doesn't leak its value into the next test.
+//      Tests can freely set process.env['HOME'] = customDir without saving the
+//      previous value - the next test gets a fresh sandbox baseline.
+//
+// CAVEAT: env vars set in a test file's beforeAll() get overwritten by this
+// file's beforeEach before each test runs. Use beforeEach (not beforeAll) when
+// the test body depends on a specific env var value.
+
+import { mkdtempSync } from 'fs'
+import { tmpdir } from 'os'
+import { join } from 'path'
+import { beforeEach } from 'vitest'
+
+const sandbox = mkdtempSync(join(tmpdir(), 'codeburn-test-env-'))
+
+const REDIRECTED = [
+  'HOME',
+  'XDG_CONFIG_HOME',
+  'XDG_DATA_HOME',
+  'XDG_CACHE_HOME',
+  'XDG_STATE_HOME',
+  'APPDATA',
+  'LOCALAPPDATA',
+] as const
+
+const CLEARED = [
+  // Provider session-discovery dirs
+  'CLAUDE_CONFIG_DIR',
+  'CLAUDE_CONFIG_DIRS',
+  'CODEX_HOME',
+  'CRUSH_GLOBAL_DATA',
+  'CODEBUFF_DATA_DIR',
+  'FACTORY_DIR',
+  'GOOSE_PATH_ROOT',
+  'GROK_HOME',
+  'KIRO_HOME',
+  'KIMI_SHARE_DIR',
+  'MUX_ROOT',
+  'QWEN_DATA_DIR',
+  'VIBE_HOME',
+  'WARP_DB_PATH',
+  'ZS_DATA_DIR',
+  // codeburn override dirs / paths
+  'CODEBURN_CACHE_DIR',
+  'CODEBURN_COPILOT_JETBRAINS_DIR',
+  'CODEBURN_COPILOT_OTEL_DB',
+  'CODEBURN_COPILOT_SESSION_STATE_DIR',
+  'CODEBURN_COPILOT_WS_STORAGE_DIR',
+  'CODEBURN_DESKTOP_SESSIONS_DIR',
+  'CODEBURN_MUX_DIR',
+  'CODEBURN_ANTIGRAVITY_SETTINGS_PATH',
+  // codeburn behavior toggles (set by the dev to tweak local runs)
+  'CODEBURN_COPILOT_DISABLE_OTEL',
+  'CODEBURN_TZ',
+  'CODEBURN_VERBOSE',
+  'CODEBURN_CURSOR_MAX_BUBBLES',
+  'CODEBURN_FORCE_MACOS_MAJOR',
+  // Provider model/credential overrides
+  'KIMI_MODEL_NAME',
+  'AI_GATEWAY_API_KEY',
+  'VERCEL_OIDC_TOKEN',
+  // Read by detectBashBloat - a dev's real shell limit must not bleed in
+  'BASH_MAX_OUTPUT_LENGTH',
+] as const
+
+// Snapshotted from the dev's shell and restored every test. These can't be
+// wiped (Node needs PATH for spawn / module resolution, dashboard/table layout
+// reads COLUMNS) but a test that mutates them shouldn't leak.
+const PRESERVED = ['PATH', 'COLUMNS'] as const
+const preservedSnapshot = new Map<string, string | undefined>()
+for (const key of PRESERVED) preservedSnapshot.set(key, process.env[key])
+
+function applyIsolation(): void {
+  for (const key of REDIRECTED) process.env[key] = sandbox
+  for (const key of CLEARED) delete process.env[key]
+  for (const key of PRESERVED) {
+    const original = preservedSnapshot.get(key)
+    if (original === undefined) delete process.env[key]
+    else process.env[key] = original
+  }
+  // Pin the timezone so date grouping is deterministic regardless of the dev's
+  // shell TZ. Clearing it is not enough (Node falls back to the OS zone); a
+  // non-UTC TZ would otherwise shift day buckets versus a clean CI runner. A
+  // test that needs a specific zone can still set process.env.TZ in beforeEach.
+  process.env.TZ = 'UTC'
+}
+
+applyIsolation()
+beforeEach(applyIsolation)