fix(build): respect PATH-less pnpm environments

scripts/lib/format-generated-module.mjs

@@ -25,6 +25,8 @@ export function resolveGeneratedModuleFormatter(params) {
 
   return resolvePnpmRunner({
     comSpec: params.comSpec,
+    cwd: params.repoRoot,
+    env: params.env,
     npmExecPath: params.npmExecPath,
     nodeExecPath: params.nodeExecPath,
     platform,

scripts/pnpm-runner.mjs

@@ -2,7 +2,7 @@
 import { spawn } from "node:child_process";
 import { accessSync, closeSync, constants, openSync, readSync, statSync } from "node:fs";
 import path from "node:path";
-import { buildCmdExeCommandLine } from "./windows-cmd-helpers.mjs";
+import { buildCmdExeCommandLine, resolvePathEnvKey } from "./windows-cmd-helpers.mjs";
 
 function getPortableBasename(value) {
   return value.split(/[/\\]/).at(-1) ?? value;
@@ -55,22 +55,47 @@ function isFile(value) {
   }
 }
 
-function findExecutableOnPath(command, envPath) {
+function findExecutableOnPath(command, envPath, platform, env, cwd) {
   if (typeof envPath !== "string" || envPath.length === 0) {
     return null;
   }
-  for (const directory of envPath.split(path.delimiter)) {
+  const extensions =
+    platform === "win32"
+      ? (env[Object.keys(env).find((key) => key.toLowerCase() === "pathext") ?? "PATHEXT"] ??
+          ".COM;.EXE;.BAT;.CMD")
+          .split(";")
+          .filter(Boolean)
+          .map((extension) => extension.toLowerCase())
+      : [""];
+  const pathDelimiter = platform === "win32" ? ";" : path.delimiter;
+  for (const directory of envPath.split(pathDelimiter)) {
     if (!directory) {
       continue;
     }
-    const candidate = path.join(directory, command);
-    if (isExecutableFile(candidate)) {
-      return candidate;
+    const resolvedDirectory = path.isAbsolute(directory) ? directory : path.resolve(cwd, directory);
+    for (const extension of extensions) {
+      const candidate = path.join(resolvedDirectory, `${command}${extension}`);
+      if ((platform === "win32" ? isFile(candidate) : isExecutableFile(candidate))) {
+        return candidate;
+      }
     }
   }
   return null;
 }
 
+function createWindowsRunner(command, args, comSpec) {
+  const extension = getPortableExtension(command);
+  if (extension === ".cmd" || extension === ".bat") {
+    return {
+      command: comSpec,
+      args: ["/d", "/s", "/c", buildCmdExeCommandLine(command, args)],
+      shell: false,
+      windowsVerbatimArguments: true,
+    };
+  }
+  return { command, args, shell: false };
+}
+
 function isNodeRunnablePnpmExecPath(value) {
   if (!isPnpmExecPath(value)) {
     return false;
@@ -95,7 +120,9 @@ export function resolvePnpmRunner(params = {}) {
   const nodeExecPath = params.nodeExecPath ?? process.execPath;
   const platform = params.platform ?? process.platform;
   const comSpec = params.comSpec ?? process.env.ComSpec ?? "cmd.exe";
-  const envPath = params.env?.PATH ?? process.env.PATH;
+  const env = params.env ?? process.env;
+  const envPath = env[platform === "win32" ? resolvePathEnvKey(env) : "PATH"];
+  const cwd = params.cwd ?? process.cwd();
 
   if (typeof npmExecPath === "string" && npmExecPath.length > 0 && isPnpmExecPath(npmExecPath)) {
     if (isNodeRunnablePnpmExecPath(npmExecPath)) {
@@ -131,30 +158,22 @@ export function resolvePnpmRunner(params = {}) {
     }
   }
 
-  if (platform === "win32") {
-    return {
-      command: comSpec,
-      args: ["/d", "/s", "/c", buildCmdExeCommandLine("pnpm.cmd", pnpmArgs)],
-      shell: false,
-      windowsVerbatimArguments: true,
-    };
+  const pnpmPath = findExecutableOnPath("pnpm", envPath, platform, env, cwd);
+  if (pnpmPath) {
+    return platform === "win32"
+      ? createWindowsRunner(pnpmPath, pnpmArgs, comSpec)
+      : { command: pnpmPath, args: pnpmArgs, shell: false };
+  }
+  const corepackPath = findExecutableOnPath("corepack", envPath, platform, env, cwd);
+  if (corepackPath) {
+    const args = ["pnpm", ...pnpmArgs];
+    return platform === "win32"
+      ? createWindowsRunner(corepackPath, args, comSpec)
+      : { command: corepackPath, args, shell: false };
   }
 
-  const pnpmPath = findExecutableOnPath("pnpm", envPath);
-  if (pnpmPath) {
-    return {
-      command: pnpmPath,
-      args: pnpmArgs,
-      shell: false,
-    };
-  }
-  const corepackPath = findExecutableOnPath("corepack", envPath);
-  if (corepackPath) {
-    return {
-      command: corepackPath,
-      args: ["pnpm", ...pnpmArgs],
-      shell: false,
-    };
+  if (platform === "win32") {
+    return createWindowsRunner("pnpm.cmd", pnpmArgs, comSpec);
   }
 
   return {

scripts/ui.js

@@ -67,7 +67,9 @@ export function resolveSpawnCall(cmd, args, envOverride, params = {}) {
 export function resolvePnpmSpawnCall(pnpmArgs, envOverride, params = {}) {
   const env = envOverride ?? process.env;
   const platform = params.platform ?? process.platform;
+  const cwd = params.cwd ?? uiDir;
   const runner = resolvePnpmRunner({
+    cwd,
     env,
     pnpmArgs,
     nodeExecPath: params.nodeExecPath ?? process.execPath,
@@ -79,7 +81,7 @@ export function resolvePnpmSpawnCall(pnpmArgs, envOverride, params = {}) {
     command: runner.command,
     args: runner.args,
     options: {
-      cwd: params.cwd ?? uiDir,
+      cwd,
       stdio: "inherit",
       env,
       shell: runner.shell,

test/scripts/format-generated-module.test.ts

@@ -49,6 +49,7 @@ describe("resolveGeneratedModuleFormatter", () => {
     expect(
       resolveGeneratedModuleFormatter({
         comSpec: "C:\\Windows\\System32\\cmd.exe",
+        env: { PATH: "" },
         existsSync: () => false,
         npmExecPath: "",
         outputPath: "C:\\Users\\test\\AppData\\Local\\Temp\\generated output.ts",

test/scripts/pnpm-runner.test.ts

@@ -4,6 +4,7 @@ import os from "node:os";
 import path from "node:path";
 import { describe, expect, it } from "vitest";
 import { createPnpmRunnerSpawnSpec, resolvePnpmRunner } from "../../scripts/pnpm-runner.mjs";
+import { buildCmdExeCommandLine } from "../../scripts/windows-cmd-helpers.mjs";
 
 describe("resolvePnpmRunner", () => {
   const posixIt = process.platform === "win32" ? it.skip : it;
@@ -171,6 +172,7 @@ describe("resolvePnpmRunner", () => {
     expect(
       resolvePnpmRunner({
         comSpec: "C:\\Windows\\System32\\cmd.exe",
+        env: { PATH: "" },
         npmExecPath:
           "C:\\Users\\test\\AppData\\Local\\Temp\\cache\\corepack\\v1\\pnpm\\10.32.1\\bin\\pnpm.mjs",
         nodeExecPath: "C:\\Program Files\\nodejs\\node.exe",
@@ -221,6 +223,43 @@ describe("resolvePnpmRunner", () => {
     });
   });
 
+  posixIt("does not resolve executables from the parent PATH for an explicit empty env", () => {
+    expect(
+      resolvePnpmRunner({
+        npmExecPath: "",
+        env: {},
+        pnpmArgs: ["exec", "vitest", "run"],
+        platform: "linux",
+      }),
+    ).toEqual({
+      command: "pnpm",
+      args: ["exec", "vitest", "run"],
+      shell: false,
+    });
+  });
+
+  posixIt("resolves relative PATH entries from the child working directory", () => {
+    const childDir = mkdtempSync(path.join(os.tmpdir(), "pnpm-runner-child-"));
+
+    try {
+      expect(
+        resolvePnpmRunner({
+          cwd: childDir,
+          npmExecPath: "",
+          env: { PATH: "node_modules/.bin" },
+          pnpmArgs: ["exec", "vitest", "run"],
+          platform: "linux",
+        }),
+      ).toEqual({
+        command: "pnpm",
+        args: ["exec", "vitest", "run"],
+        shell: false,
+      });
+    } finally {
+      rmSync(childDir, { recursive: true, force: true });
+    }
+  });
+
   posixIt("uses Corepack when pnpm is not directly available on PATH", () => {
     const tempDir = mkdtempSync(path.join(os.tmpdir(), "pnpm-runner-corepack-"));
     const corepackPath = path.join(tempDir, "corepack");
@@ -276,8 +315,8 @@ describe("resolvePnpmRunner", () => {
     expect(
       resolvePnpmRunner({
         comSpec: "C:\\Windows\\System32\\cmd.exe",
-        npmExecPath: "",
         env: { PATH: "" },
+        npmExecPath: "",
         pnpmArgs: ["exec", "vitest", "run", "-t", "path with spaces"],
         platform: "win32",
       }),
@@ -289,10 +328,41 @@ describe("resolvePnpmRunner", () => {
     });
   });
 
+  it("uses Corepack on Windows when no pnpm shim is available", () => {
+    const tempDir = mkdtempSync(path.join(os.tmpdir(), "pnpm-runner-corepack-"));
+    const corepackPath = path.join(tempDir, "corepack.cmd");
+    writeFileSync(corepackPath, "@exit /b 0\r\n");
+
+    try {
+      expect(
+        resolvePnpmRunner({
+          comSpec: "C:\\Windows\\System32\\cmd.exe",
+          npmExecPath: "",
+          env: { Path: tempDir, PATHEXT: ".CMD;.EXE" },
+          pnpmArgs: ["exec", "vitest", "run"],
+          platform: "win32",
+        }),
+      ).toEqual({
+        command: "C:\\Windows\\System32\\cmd.exe",
+        args: [
+          "/d",
+          "/s",
+          "/c",
+          buildCmdExeCommandLine(corepackPath, ["pnpm", "exec", "vitest", "run"]),
+        ],
+        shell: false,
+        windowsVerbatimArguments: true,
+      });
+    } finally {
+      rmSync(tempDir, { recursive: true, force: true });
+    }
+  });
+
   it("escapes caret arguments for Windows cmd.exe", () => {
     expect(
       resolvePnpmRunner({
         comSpec: "C:\\Windows\\System32\\cmd.exe",
+        env: { PATH: "" },
         npmExecPath: "",
         pnpmArgs: ["exec", "vitest", "-t", "@scope/pkg@^1.2.3"],
         platform: "win32",