feat(cli): warn when removing the last/host target for a toolchain, pt. 2

src/cli/rustup_mode.rs

@@ -1340,14 +1340,17 @@ fn target_remove(cfg: &Cfg, m: &ArgMatches) -> Result<utils::ExitCode> {
         if target == default_target {
             warn!("after removing the default host target, proc-macros and build scripts might no longer build");
         }
-        let has_at_most_one_target = {
-            let components = distributable.components()?;
-            // Every component target that is not `None` (wildcard).
-            let targets = components
-                .iter()
-                .filter_map(|c| c.installed.then(|| c.component.target.clone()).flatten());
-            targets.unique().at_most_one().is_ok()
-        };
+        // Whether we have at most 1 component target that is not `None` (wildcard).
+        let has_at_most_one_target = distributable
+            .components()?
+            .into_iter()
+            .filter_map(|c| match (c.installed, c.component.target) {
+                (true, Some(t)) => Some(t),
+                _ => None,
+            })
+            .unique()
+            .at_most_one()
+            .is_ok();
         if has_at_most_one_target {
             warn!("after removing the last target, no build targets will be available");
         }

src/lib.rs

@@ -16,6 +16,7 @@ pub use crate::errors::*;
 pub(crate) use crate::notifications::*;
 pub(crate) use crate::utils::toml_utils;
 use anyhow::{anyhow, Result};
+use itertools::{chain, Itertools};
 
 #[macro_use]
 extern crate rs_tracing;
@@ -41,23 +42,15 @@ pub static DUP_TOOLS: &[&str] = &["rust-analyzer", "rustfmt", "cargo-fmt"];
 
 // If the given name is one of the tools we proxy.
 pub fn is_proxyable_tools(tool: &str) -> Result<()> {
-    if TOOLS
-        .iter()
-        .chain(DUP_TOOLS.iter())
-        .any(|&name| name == tool)
-    {
+    if chain!(TOOLS, DUP_TOOLS).contains(&tool) {
         Ok(())
     } else {
-        Err(anyhow!(format!(
-            "unknown proxy name: '{}'; valid proxy names are {}",
-            tool,
-            TOOLS
-                .iter()
-                .chain(DUP_TOOLS.iter())
+        Err(anyhow!(
+            "unknown proxy name: '{tool}'; valid proxy names are {}",
+            chain!(TOOLS, DUP_TOOLS)
                 .map(|s| format!("'{s}'"))
-                .collect::<Vec<_>>()
-                .join(", ")
-        )))
+                .join(", "),
+        ))
     }
 }
 

src/toolchain/distributable.rs

@@ -10,7 +10,7 @@ use crate::{
     dist::{
         config::Config,
         dist::{Profile, ToolchainDesc},
-        manifest::{Component, Manifest},
+        manifest::{Component, ComponentStatus, Manifest},
         manifestation::{Changes, Manifestation},
         prefix::InstallPrefix,
     },
@@ -115,7 +115,7 @@ impl<'a> DistributableToolchain<'a> {
         Ok(())
     }
 
-    pub(crate) fn components(&self) -> anyhow::Result<Vec<crate::dist::manifest::ComponentStatus>> {
+    pub(crate) fn components(&self) -> anyhow::Result<Vec<ComponentStatus>> {
         let manifestation = self.get_manifestation()?;
         let config = manifestation.read_config()?.unwrap_or_default();
         let manifest = self.get_manifest()?;