From 97937a097e8fe52cdefd55bf12a92e19d627aca4 Mon Sep 17 00:00:00 2001
From: David Sherret <dsherret@users.noreply.github.com>
Date: Wed, 3 Jan 2024 09:45:10 -0500
Subject: [PATCH] fix(jupyter): error message when install fails due to jupyter
 command not being on PATH (#21767)

We were failing silently in this scenario.
---
 cli/tests/integration/jupyter_tests.rs        |  8 +++++
 cli/tests/integration/mod.rs                  |  5 ++-
 .../jupyter/install_command_not_exists.out    |  4 +++
 cli/tools/jupyter/install.rs                  | 36 +++++++++++++------
 4 files changed, 42 insertions(+), 11 deletions(-)
 create mode 100644 cli/tests/integration/jupyter_tests.rs
 create mode 100644 cli/tests/testdata/jupyter/install_command_not_exists.out

diff --git a/cli/tests/integration/jupyter_tests.rs b/cli/tests/integration/jupyter_tests.rs
new file mode 100644
index 0000000000..847290ef82
--- /dev/null
+++ b/cli/tests/integration/jupyter_tests.rs
@@ -0,0 +1,8 @@
+// Copyright 2018-2024 the Deno authors. All rights reserved. MIT license.
+
+itest!(jupyter_install_command_not_exists {
+  args: "jupyter --unstable --install",
+  output: "jupyter/install_command_not_exists.out",
+  envs: vec![("PATH".to_string(), "".to_string())],
+  exit_code: 1,
+});
diff --git a/cli/tests/integration/mod.rs b/cli/tests/integration/mod.rs
index f599e2e879..19796f245f 100644
--- a/cli/tests/integration/mod.rs
+++ b/cli/tests/integration/mod.rs
@@ -121,7 +121,10 @@ mod inspector;
 mod install;
 #[path = "js_unit_tests.rs"]
 mod js_unit_tests;
-mod jsr_tests;
+#[path = "jsr_tests.rs"]
+mod jsr;
+#[path = "jupyter_tests.rs"]
+mod jupyter;
 #[path = "lint_tests.rs"]
 mod lint;
 #[path = "lsp_tests.rs"]
diff --git a/cli/tests/testdata/jupyter/install_command_not_exists.out b/cli/tests/testdata/jupyter/install_command_not_exists.out
new file mode 100644
index 0000000000..3d599f7fc1
--- /dev/null
+++ b/cli/tests/testdata/jupyter/install_command_not_exists.out
@@ -0,0 +1,4 @@
+error: Failed to spawn 'jupyter' command. Is JupyterLab installed (https://jupyter.org/install) and available on the PATH?
+
+Caused by:
+[WILDCARD]
diff --git a/cli/tools/jupyter/install.rs b/cli/tools/jupyter/install.rs
index ef442e1255..3b2079db06 100644
--- a/cli/tools/jupyter/install.rs
+++ b/cli/tools/jupyter/install.rs
@@ -6,6 +6,7 @@ use deno_core::error::AnyError;
 use deno_core::serde_json;
 use deno_core::serde_json::json;
 use std::env::current_exe;
+use std::io::ErrorKind;
 use std::io::Write;
 use std::path::Path;
 use tempfile::TempDir;
@@ -76,19 +77,34 @@ pub fn install() -> Result<(), AnyError> {
       &temp_dir.path().to_string_lossy(),
     ])
     .spawn();
+  let mut child = match child_result {
+    Ok(child) => child,
+    Err(err)
+      if matches!(
+        err.kind(),
+        ErrorKind::NotFound | ErrorKind::PermissionDenied
+      ) =>
+    {
+      return Err(err).context(concat!(
+        "Failed to spawn 'jupyter' command. Is JupyterLab installed ",
+        "(https://jupyter.org/install) and available on the PATH?"
+      ));
+    }
+    Err(err) => {
+      return Err(err).context("Failed to spawn 'jupyter' command.");
+    }
+  };
 
-  if let Ok(mut child) = child_result {
-    let wait_result = child.wait();
-    match wait_result {
-      Ok(status) => {
-        if !status.success() {
-          bail!("Failed to install kernelspec, try again.");
-        }
-      }
-      Err(err) => {
-        bail!("Failed to install kernelspec: {}", err);
+  let wait_result = child.wait();
+  match wait_result {
+    Ok(status) => {
+      if !status.success() {
+        bail!("Failed to install kernelspec, try again.");
       }
     }
+    Err(err) => {
+      bail!("Failed to install kernelspec: {}", err);
+    }
   }
 
   let _ = std::fs::remove_dir(temp_dir);