check: ignore environment checks if NH_NO_CHECKS is set

Author: NotAShelf

src/check.rs

@@ -13,6 +13,10 @@ use crate::util;
 ///
 /// * `Result<()>` - Ok if version requirements are met, error otherwise
 pub fn check_nix_version() -> Result<()> {
+    if env::var("NH_NO_CHECKS").is_ok() {
+        return Ok(());
+    }
+
     let version = util::get_nix_version()?;
     let is_lix_binary = util::is_lix()?;
 
@@ -63,6 +67,10 @@ pub fn check_nix_version() -> Result<()> {
 ///
 /// * `Result<()>` - Ok if all required features are enabled, error otherwise
 pub fn check_nix_features() -> Result<()> {
+    if env::var("NH_NO_CHECKS").is_ok() {
+        return Ok(());
+    }
+
     let mut required_features = vec!["nix-command", "flakes"];
 
     // Lix still uses repl-flake, which is removed in the latest version of Nix.
@@ -115,6 +123,10 @@ pub fn setup_environment() -> Result<bool> {
 ///
 /// * `Result<()>` - Ok if all checks pass, error otherwise
 pub fn verify_nix_environment() -> Result<()> {
+    if env::var("NH_NO_CHECKS").is_ok() {
+        return Ok(());
+    }
+
     check_nix_version()?;
     check_nix_features()?;
     Ok(())
@@ -134,6 +146,7 @@ fn cleanup_env_vars() {
     env::remove_var("NH_OS_FLAKE");
     env::remove_var("NH_HOME_FLAKE");
     env::remove_var("NH_DARWIN_FLAKE");
+    env::remove_var("NH_NO_CHECKS");
 }
 
 #[test]
@@ -276,3 +289,23 @@ fn test_setup_environment_flake_set_no_nh_flake_nh_darwin_flake_set() -> Result<
     cleanup_env_vars(); // Clean up after test
     Ok(())
 }
+
+#[test]
+fn test_checks_skip_when_no_checks_set() -> Result<()> {
+    let _lock = ENV_LOCK.lock().unwrap();
+    cleanup_env_vars();
+
+    env::set_var("NH_NO_CHECKS", "1");
+
+    // These should succeed even with invalid environment
+    let version_check = check_nix_version();
+    let features_check = check_nix_features();
+    let verify_check = verify_nix_environment();
+
+    assert!(version_check.is_ok(), "Version check should be skipped");
+    assert!(features_check.is_ok(), "Features check should be skipped");
+    assert!(verify_check.is_ok(), "Verify check should be skipped");
+
+    cleanup_env_vars();
+    Ok(())
+}

src/util.rs

@@ -1,11 +1,12 @@
 use std::collections::HashSet;
 use std::path::{Path, PathBuf};
-use std::process::Command;
 use std::str;
 
 use color_eyre::{eyre, Result};
 use tempfile::TempDir;
 
+use crate::commands::Command;
+
 /// Retrieves the installed Nix version as a string.
 ///
 /// This function executes the `nix --version` command, parses the output to extract the version string,
@@ -15,10 +16,12 @@ use tempfile::TempDir;
 ///
 /// * `Result<String>` - The Nix version string or an error if the version cannot be retrieved.
 pub fn get_nix_version() -> Result<String> {
-    let output = Command::new("nix").arg("--version").output()?;
+    let output = Command::new("nix")
+        .arg("--version")
+        .run_capture()?
+        .ok_or_else(|| eyre::eyre!("No output from command"))?;
 
-    let output_str = str::from_utf8(&output.stdout)?;
-    let version_str = output_str
+    let version_str = output
         .lines()
         .next()
         .ok_or_else(|| eyre::eyre!("No version string found"))?;
@@ -42,10 +45,12 @@ pub fn get_nix_version() -> Result<String> {
 ///
 /// * `Result<bool>` - True if the binary is Lix, false if it's standard Nix
 pub fn is_lix() -> Result<bool> {
-    let output = Command::new("nix").arg("--version").output()?;
-    let output_str = str::from_utf8(&output.stdout)?.to_lowercase();
+    let output = Command::new("nix")
+        .arg("--version")
+        .run_capture()?
+        .ok_or_else(|| eyre::eyre!("No output from command"))?;
 
-    Ok(output_str.contains("lix"))
+    Ok(output.to_lowercase().contains("lix"))
 }
 
 /// Represents an object that may be a temporary path
@@ -109,16 +114,14 @@ pub fn get_hostname() -> Result<String> {
 pub fn get_nix_experimental_features() -> Result<HashSet<String>> {
     let output = Command::new("nix")
         .args(["config", "show", "experimental-features"])
-        .output()?;
+        .run_capture()?;
 
-    if !output.status.success() {
-        return Err(eyre::eyre!(
-            "Failed to get experimental features: {}",
-            String::from_utf8_lossy(&output.stderr)
-        ));
-    }
+    // If running with dry=true, output might be None
+    let output_str = match output {
+        Some(output) => output,
+        None => return Ok(HashSet::new()),
+    };
 
-    let output_str = str::from_utf8(&output.stdout)?;
     let enabled_features: HashSet<String> =
         output_str.split_whitespace().map(String::from).collect();