fix(task): regression where npx <command> sometimes couldn't find command (#23730)

Closes https://github.com/denoland/deno/issues/23724

Cargo.lock

@@ -1876,9 +1876,9 @@ dependencies = [
 
 [[package]]
 name = "deno_task_shell"
-version = "0.16.0"
+version = "0.16.1"
 source = "registry+https://github.com/rust-lang/crates.io-index"
-checksum = "6b44af10161906e1bccc1fc966f074bec0148997bb7e2221ecd29416dcad90b3"
+checksum = "97e5ff66a1e89edb7ca0c36b73a8fcdc008ba426c4ad7a36e1dfb3f4a166179e"
 dependencies = [
  "anyhow",
  "futures",

cli/Cargo.toml

@@ -75,7 +75,7 @@ deno_lockfile.workspace = true
 deno_npm = "=0.18.0"
 deno_runtime = { workspace = true, features = ["include_js_files_for_snapshotting"] }
 deno_semver = "=0.5.4"
-deno_task_shell = "=0.16.0"
+deno_task_shell = "=0.16.1"
 deno_terminal.workspace = true
 eszip = "=0.68.2"
 napi_sym.workspace = true

cli/tools/task.rs

@@ -16,6 +16,7 @@ use deno_core::futures;
 use deno_core::futures::future::LocalBoxFuture;
 use deno_runtime::deno_node::NodeResolver;
 use deno_semver::package::PackageNv;
+use deno_task_shell::ExecutableCommand;
 use deno_task_shell::ExecuteResult;
 use deno_task_shell::ShellCommand;
 use deno_task_shell::ShellCommandContext;
@@ -236,7 +237,15 @@ fn prepend_to_path(env_vars: &mut HashMap<String, String>, value: String) {
 
 fn collect_env_vars() -> HashMap<String, String> {
   // get the starting env vars (the PWD env var will be set by deno_task_shell)
-  let mut env_vars = std::env::vars().collect::<HashMap<String, String>>();
+  let mut env_vars = std::env::vars()
+    .map(|(k, v)| {
+      if cfg!(windows) {
+        (k.to_uppercase(), v)
+      } else {
+        (k, v)
+      }
+    })
+    .collect::<HashMap<String, String>>();
   const INIT_CWD_NAME: &str = "INIT_CWD";
   if !env_vars.contains_key(INIT_CWD_NAME) {
     if let Ok(cwd) = std::env::current_dir() {
@@ -318,10 +327,17 @@ impl ShellCommand for NpxCommand {
         };
         command.execute(context)
       } else {
-        let _ = context
-          .stderr
-          .write_line(&format!("npx: could not resolve command '{first_arg}'"));
-        Box::pin(futures::future::ready(ExecuteResult::from_exit_code(1)))
+        // can't find the command, so fallback to running the real npx command
+        let npx_path = match context.resolve_command_path("npx") {
+          Ok(npx) => npx,
+          Err(err) => {
+            let _ = context.stderr.write_line(&format!("{}", err));
+            return Box::pin(futures::future::ready(
+              ExecuteResult::from_exit_code(err.exit_code()),
+            ));
+          }
+        };
+        ExecutableCommand::new("npx".to_string(), npx_path).execute(context)
       }
     } else {
       let _ = context.stderr.write_line("npx: missing command");

tests/specs/task/npx_installed_pkg_non_byonm/__test__.jsonc

@@ -0,0 +1,11 @@
+{
+  "tempDir": true,
+  "steps": [{
+    "commandName": "npm",
+    "args": "install",
+    "output": "[WILDCARD]"
+  }, {
+    "args": "task say",
+    "output": "main.out"
+  }]
+}

tests/specs/task/npx_installed_pkg_non_byonm/deno.jsonc

@@ -0,0 +1,7 @@
+{
+  // not byonm
+  "nodeModulesDir": true,
+  "tasks": {
+    "say": "npx cowsay moo"
+  }
+}

tests/specs/task/npx_installed_pkg_non_byonm/main.out

@@ -0,0 +1,9 @@
+Task say npx cowsay moo
+ _____
+< moo >
+ -----
+        \   ^__^
+         \  (oo)\_______
+            (__)\       )\/\
+                ||----w |
+                ||     ||

tests/specs/task/npx_installed_pkg_non_byonm/package.json

@@ -0,0 +1,5 @@
+{
+  "dependencies": {
+    "cowsay": "*"
+  }
+}

tests/testdata/task/npx/non_existent.out

@@ -1,2 +1,4 @@
 Task non-existent npx this-command-should-not-exist-for-you
-npx: could not resolve command 'this-command-should-not-exist-for-you'
+npm ERR! code E404
+npm ERR! 404 Not Found - GET http://localhost:4260/this-command-should-not-exist-for-you
+[WILDCARD]