fix: workaround for pnpm and TMPDIR (#123)

src/jiti.ts

@@ -1,7 +1,7 @@
 import { existsSync, readFileSync, writeFileSync, mkdirSync } from "fs";
 import { Module, builtinModules } from "module";
 import { performance } from "perf_hooks";
-import { tmpdir, platform } from "os";
+import { platform } from "os";
 import vm from "vm";
 import { fileURLToPath, pathToFileURL } from "url";
 import { dirname, join, basename, extname } from "pathe";
@@ -14,6 +14,7 @@ import { addHook } from "pirates";
 import objectHash from "object-hash";
 import { hasESMSyntax, interopDefault, resolvePathSync } from "mlly";
 import {
+  getCacheDir,
   isDir,
   isWritable,
   md5,
@@ -106,7 +107,7 @@ export default function createJITI(
   }
 
   if (opts.cache === true) {
-    opts.cache = join(tmpdir(), "node-jiti");
+    opts.cache = getCacheDir();
   }
   if (opts.cache) {
     try {

src/utils.ts

@@ -1,8 +1,30 @@
 import { lstatSync, accessSync, constants, readFileSync } from "fs";
 import { createHash } from "crypto";
+import { tmpdir } from "os";
 import { join } from "pathe";
 import type { PackageJson } from "pkg-types";
 
+export function getCacheDir() {
+  let _tmpDir = tmpdir();
+
+  // Workaround for pnpm setting an incorrect `TMPDIR`.
+  // Set `JITI_RESPECT_TMPDIR_ENV` to a truthy value to disable this workaround.
+  // https://github.com/pnpm/pnpm/issues/6140
+  // https://github.com/unjs/jiti/issues/120
+  if (
+    process.env.TMPDIR &&
+    _tmpDir === process.cwd() &&
+    !process.env.JITI_RESPECT_TMPDIR_ENV
+  ) {
+    const _env = process.env.TMPDIR;
+    delete process.env.TMPDIR;
+    _tmpDir = tmpdir();
+    process.env.TMPDIR = _env;
+  }
+
+  return join(_tmpDir, "node-jiti");
+}
+
 export function isDir(filename: string): boolean {
   try {
     const stat = lstatSync(filename);

test/utils.test.ts

@@ -0,0 +1,43 @@
+import { afterEach, describe, beforeEach, it, expect, vi } from "vitest";
+
+import { getCacheDir } from "../src/utils";
+
+describe("utils", () => {
+  describe("getCacheDir", () => {
+    const cwd = "/cwd";
+    const notCwd = `${cwd}__NOT__`;
+
+    beforeEach(() => {
+      vi.spyOn(process, "cwd").mockImplementation(() => cwd);
+    });
+
+    afterEach(() => {
+      vi.restoreAllMocks();
+      vi.unstubAllEnvs();
+    });
+
+    it("returns the system's TMPDIR when TMPDIR is not set", () => {
+      const originalTmpdir = process.env.TMPDIR;
+      delete process.env.TMPDIR;
+      expect(getCacheDir()).toBe("/tmp/node-jiti");
+      process.env.TMPDIR = originalTmpdir;
+    });
+
+    it("returns TMPDIR when TMPDIR is not CWD", () => {
+      vi.stubEnv("TMPDIR", notCwd);
+      expect(getCacheDir()).toBe("/cwd__NOT__/node-jiti");
+    });
+
+    it("returns the system's TMPDIR when TMPDIR is CWD", () => {
+      vi.stubEnv("TMPDIR", cwd);
+      expect(getCacheDir()).toBe("/tmp/node-jiti");
+    });
+
+    it("returns TMPDIR when TMPDIR is CWD and TMPDIR is kept", () => {
+      vi.stubEnv("TMPDIR", cwd);
+      vi.stubEnv("JITI_RESPECT_TMPDIR_ENV", "true");
+
+      expect(getCacheDir()).toBe("/cwd/node-jiti");
+    });
+  });
+});