Volta npm shim ignores the --dry-run flag

[jasonmobley]

Running npm install -g --dry-run <package> should not actually install anything. Volta's npm shim doesn't honor the --dry-run flag and does the actual install.

→ volta ls yarn
⚡️ Yarn versions in your toolchain:

    v1.22.17
    v1.22.19
    v1.22.21 (default)

→ npm install -g --dry-run yarn
   note: using Volta to install Yarn
success: installed and set [email protected] as default

→ volta ls yarn
⚡️ Yarn versions in your toolchain:

    v1.22.17
    v1.22.19
    v1.22.21
    v4.0.2 (default)

→

[chriskrycho]

Thanks for the report! Is this package-manager-specific behavior or do we get it wrong for regular packages as well?

[jasonmobley]

Thanks for the report! Is this package-manager-specific behavior or do we get it wrong for regular packages as well?

I think it is specific to the special packages that volta considers "tools" like npm, pnpm, yarn, etc. But there's also a volta bug in the general package case, because it thinks it should be trying to identify a newly installed package when there isn't one.

→ volta ls gulp
⚡️ No tools or packages installed.

You can safely install packages by running `volta install <package name>`.
See `volta help install` for details and more options.

→ npm ls -g gulp
/Users/me/.volta/tools/image/node/16.20.2/lib
└── (empty)


→ npm install -g --dry-run gulp

added 336 packages in 8s

16 packages are looking for funding
  run `npm fund` for details
Volta error: Could not determine the name of the package that was just installed.

Please rerun the command that triggered this error with the environment
variable `VOLTA_LOGLEVEL` set to `debug` and open an issue at
https://github.com/volta-cli/volta/issues with the details!

[chriskrycho]

Ah, very interesting. Thanks for flagging up that second issue as well! If you have time and interest to dig in, the relevant code is here:

volta/crates/volta-core/src/tool/package/install.rs

Lines 1 to 58 in 589116d

	use std::path::PathBuf;
	use super::manager::PackageManager;
	use crate::command::create_command;
	use crate::error::{Context, ErrorKind, Fallible};
	use crate::platform::Image;
	use crate::style::progress_spinner;
	use log::debug;
	/// Use `npm install --global` to install the package
	///
	/// Sets the environment variable `npm_config_prefix` to redirect the install to the Volta
	/// data directory, taking advantage of the standard global install behavior with a custom
	/// location
	pub(super) fn run_global_install(
	package: String,
	staging_dir: PathBuf,
	platform_image: &Image,
	) -> Fallible<()> {
	let mut command = create_command("npm");
	command.args(&[
	"install",
	"--global",
	"--loglevel=warn",
	"--no-update-notifier",
	"--no-audit",
	]);
	command.arg(&package);
	command.env("PATH", platform_image.path()?);
	PackageManager::Npm.setup_global_command(&mut command, staging_dir);
	debug!("Installing {} with command: {:?}", package, command);
	let spinner = progress_spinner(format!("Installing {}", package));
	let output_result = command
	.output()
	.with_context(|| ErrorKind::PackageInstallFailed {
	package: package.clone(),
	});
	spinner.finish_and_clear();
	let output = output_result?;
	let stderr = String::from_utf8_lossy(&output.stderr);
	debug!("[install stderr]\n{}", stderr);
	debug!(
	"[install stdout]\n{}",
	String::from_utf8_lossy(&output.stdout)
	);
	if output.status.success() {
	Ok(())
	} else if stderr.contains("code E404") {
	// npm outputs "code E404" as part of the error output when a package couldn't be found
	// Detect that and show a nicer error message (since we likely know the problem in that case)
	Err(ErrorKind::PackageNotFound { package }.into())
	} else {
	Err(ErrorKind::PackageInstallFailed { package }.into())
	}
	}

(No worries if not!)