Add --health command for troubleshooting (#1669)

* Move runtime file location definitions to core

* Add basic --health command

* Add language specific --health

* Show summary for all langs with bare --health

* Use TsFeature from xtask for --health

* cargo fmt

Co-authored-by: Blaž Hrastnik <blaz@mxxn.io>

6 files changed, 259 insertions, 18 deletions

diff --git a/helix-term/Cargo.toml b/helix-term/Cargo.toml
index 5b5a8f64..9f7821f6 100644
--- a/helix-term/Cargo.toml
+++ b/helix-term/Cargo.toml
@@ -30,6 +30,8 @@ helix-dap = { version = "0.6", path = "../helix-dap" }
 anyhow = "1"
 once_cell = "1.10"
 
+which = "4.2"
+
 tokio = { version = "1", features = ["rt", "rt-multi-thread", "io-util", "io-std", "time", "process", "macros", "fs", "parking_lot"] }
 num_cpus = "1"
 tui = { path = "../helix-tui", package = "helix-tui", default-features = false, features = ["crossterm"] }
diff --git a/helix-term/src/application.rs b/helix-term/src/application.rs
index 1b8aba6a..3eee3396 100644
--- a/helix-term/src/application.rs
+++ b/helix-term/src/application.rs
@@ -66,7 +66,6 @@ impl Application {
         let theme_loader =
             std::sync::Arc::new(theme::Loader::new(&conf_dir, &helix_core::runtime_dir()));
 
-        // load default and user config, and merge both
         let true_color = config.editor.true_color || crate::true_color();
         let theme = config
             .theme
diff --git a/helix-term/src/args.rs b/helix-term/src/args.rs
index 3e50f66f..4f386aea 100644
--- a/helix-term/src/args.rs
+++ b/helix-term/src/args.rs
@@ -1,4 +1,4 @@
-use anyhow::{Error, Result};
+use anyhow::Result;
 use helix_core::Position;
 use std::path::{Path, PathBuf};
 
@@ -6,6 +6,8 @@ use std::path::{Path, PathBuf};
 pub struct Args {
     pub display_help: bool,
     pub display_version: bool,
+    pub health: bool,
+    pub health_arg: Option<String>,
     pub load_tutor: bool,
     pub verbosity: u64,
     pub files: Vec<(PathBuf, Position)>,
@@ -14,22 +16,22 @@ pub struct Args {
 impl Args {
     pub fn parse_args() -> Result<Args> {
         let mut args = Args::default();
-        let argv: Vec<String> = std::env::args().collect();
-        let mut iter = argv.iter();
+        let mut argv = std::env::args().peekable();
 
-        iter.next(); // skip the program, we don't care about that
+        argv.next(); // skip the program, we don't care about that
 
-        for arg in &mut iter {
+        while let Some(arg) = argv.next() {
             match arg.as_str() {
                 "--" => break, // stop parsing at this point treat the remaining as files
                 "--version" => args.display_version = true,
                 "--help" => args.display_help = true,
                 "--tutor" => args.load_tutor = true,
+                "--health" => {
+                    args.health = true;
+                    args.health_arg = argv.next_if(|opt| !opt.starts_with('-'));
+                }
                 arg if arg.starts_with("--") => {
-                    return Err(Error::msg(format!(
-                        "unexpected double dash argument: {}",
-                        arg
-                    )))
+                    anyhow::bail!("unexpected double dash argument: {}", arg)
                 }
                 arg if arg.starts_with('-') => {
                     let arg = arg.get(1..).unwrap().chars();
@@ -38,7 +40,7 @@ impl Args {
                             'v' => args.verbosity += 1,
                             'V' => args.display_version = true,
                             'h' => args.display_help = true,
-                            _ => return Err(Error::msg(format!("unexpected short arg {}", chr))),
+                            _ => anyhow::bail!("unexpected short arg {}", chr),
                         }
                     }
                 }
@@ -47,8 +49,8 @@ impl Args {
         }
 
         // push the remaining args, if any to the files
-        for arg in iter {
-            args.files.push(parse_file(arg));
+        for arg in argv {
+            args.files.push(parse_file(&arg));
         }
 
         Ok(args)
diff --git a/helix-term/src/health.rs b/helix-term/src/health.rs
new file mode 100644
index 00000000..5ef20d93
--- /dev/null
+++ b/helix-term/src/health.rs
@@ -0,0 +1,221 @@
+use crossterm::style::{Color, Print, Stylize};
+use helix_core::{
+    config::{default_syntax_loader, user_syntax_loader},
+    syntax::load_runtime_file,
+};
+
+#[derive(Copy, Clone)]
+pub enum TsFeature {
+    Highlight,
+    TextObject,
+    AutoIndent,
+}
+
+impl TsFeature {
+    pub fn all() -> &'static [Self] {
+        &[Self::Highlight, Self::TextObject, Self::AutoIndent]
+    }
+
+    pub fn runtime_filename(&self) -> &'static str {
+        match *self {
+            Self::Highlight => "highlights.scm",
+            Self::TextObject => "textobjects.scm",
+            Self::AutoIndent => "indents.toml",
+        }
+    }
+
+    pub fn long_title(&self) -> &'static str {
+        match *self {
+            Self::Highlight => "Syntax Highlighting",
+            Self::TextObject => "Treesitter Textobjects",
+            Self::AutoIndent => "Auto Indent",
+        }
+    }
+
+    pub fn short_title(&self) -> &'static str {
+        match *self {
+            Self::Highlight => "Highlight",
+            Self::TextObject => "Textobject",
+            Self::AutoIndent => "Indent",
+        }
+    }
+}
+
+/// Display general diagnostics.
+pub fn general() {
+    let config_file = helix_core::config_file();
+    let lang_file = helix_core::lang_config_file();
+    let log_file = helix_core::log_file();
+    let rt_dir = helix_core::runtime_dir();
+
+    if config_file.exists() {
+        println!("Config file: {}", config_file.display());
+    } else {
+        println!("Config file: default")
+    }
+    if lang_file.exists() {
+        println!("Language file: {}", lang_file.display());
+    } else {
+        println!("Language file: default")
+    }
+    println!("Log file: {}", log_file.display());
+    println!("Runtime directory: {}", rt_dir.display());
+
+    if let Ok(path) = std::fs::read_link(&rt_dir) {
+        let msg = format!("Runtime directory is symlinked to {}", path.display());
+        println!("{}", msg.yellow());
+    }
+    if !rt_dir.exists() {
+        println!("{}", "Runtime directory does not exist.".red());
+    }
+    if rt_dir.read_dir().ok().map(|it| it.count()) == Some(0) {
+        println!("{}", "Runtime directory is empty.".red());
+    }
+}
+
+pub fn languages_all() {
+    let mut syn_loader_conf = user_syntax_loader().unwrap_or_else(|err| {
+        eprintln!("{}: {}", "Error parsing user language config".red(), err);
+        eprintln!("{}", "Using default language config".yellow());
+        default_syntax_loader()
+    });
+
+    let mut headings = vec!["Language", "LSP", "DAP"];
+
+    for feat in TsFeature::all() {
+        headings.push(feat.short_title())
+    }
+
+    let terminal_cols = crossterm::terminal::size().map(|(c, _)| c).unwrap_or(80);
+    let column_width = terminal_cols as usize / headings.len();
+
+    let column = |item: &str, color: Color| {
+        let data = format!(
+            "{:column_width$}",
+            item.get(..column_width - 2)
+                .map(|s| format!("{s}…"))
+                .unwrap_or_else(|| item.to_string())
+        )
+        .stylize()
+        .with(color);
+
+        // We can't directly use println!() because of
+        // https://github.com/crossterm-rs/crossterm/issues/589
+        let _ = crossterm::execute!(std::io::stdout(), Print(data));
+    };
+
+    for heading in headings {
+        column(heading, Color::White);
+    }
+    println!();
+
+    syn_loader_conf
+        .language
+        .sort_unstable_by_key(|l| l.language_id.clone());
+
+    let check_binary = |cmd: Option<String>| match cmd {
+        Some(cmd) => match which::which(&cmd) {
+            Ok(_) => column(&cmd, Color::Green),
+            Err(_) => column(&cmd, Color::Red),
+        },
+        None => column("None", Color::Yellow),
+    };
+
+    for lang in &syn_loader_conf.language {
+        column(&lang.language_id, Color::Reset);
+
+        let lsp = lang
+            .language_server
+            .as_ref()
+            .map(|lsp| lsp.command.to_string());
+        check_binary(lsp);
+
+        let dap = lang.debugger.as_ref().map(|dap| dap.command.to_string());
+        check_binary(dap);
+
+        for ts_feat in TsFeature::all() {
+            match load_runtime_file(&lang.language_id, ts_feat.runtime_filename()).is_ok() {
+                true => column("Found", Color::Green),
+                false => column("Not Found", Color::Red),
+            }
+        }
+
+        println!();
+    }
+}
+
+/// Display diagnostics pertaining to a particular language (LSP,
+/// highlight queries, etc).
+pub fn language(lang_str: String) {
+    let syn_loader_conf = user_syntax_loader().unwrap_or_else(|err| {
+        eprintln!("{}: {}", "Error parsing user language config".red(), err);
+        eprintln!("{}", "Using default language config".yellow());
+        default_syntax_loader()
+    });
+
+    let lang = match syn_loader_conf
+        .language
+        .iter()
+        .find(|l| l.language_id == lang_str)
+    {
+        Some(l) => l,
+        None => {
+            let msg = format!("Language '{lang_str}' not found");
+            println!("{}", msg.red());
+            let suggestions: Vec<&str> = syn_loader_conf
+                .language
+                .iter()
+                .filter(|l| l.language_id.starts_with(lang_str.chars().next().unwrap()))
+                .map(|l| l.language_id.as_str())
+                .collect();
+            if !suggestions.is_empty() {
+                let suggestions = suggestions.join(", ");
+                println!("Did you mean one of these: {} ?", suggestions.yellow());
+            }
+            return;
+        }
+    };
+
+    probe_protocol(
+        "language server",
+        lang.language_server
+            .as_ref()
+            .map(|lsp| lsp.command.to_string()),
+    );
+
+    probe_protocol(
+        "debug adapter",
+        lang.debugger.as_ref().map(|dap| dap.command.to_string()),
+    );
+
+    for ts_feat in TsFeature::all() {
+        probe_treesitter_feature(&lang_str, *ts_feat)
+    }
+}
+
+/// Display diagnostics about LSP and DAP.
+fn probe_protocol(protocol_name: &str, server_cmd: Option<String>) {
+    let cmd_name = match server_cmd {
+        Some(ref cmd) => cmd.as_str().green(),
+        None => "None".yellow(),
+    };
+    println!("Configured {}: {}", protocol_name, cmd_name);
+
+    if let Some(cmd) = server_cmd {
+        let path = match which::which(&cmd) {
+            Ok(path) => path.display().to_string().green(),
+            Err(_) => "Not found in $PATH".to_string().red(),
+        };
+        println!("Binary for {}: {}", protocol_name, path);
+    }
+}
+
+/// Display diagnostics about a feature that requires tree-sitter
+/// query files (highlights, textobjects, etc).
+fn probe_treesitter_feature(lang: &str, feature: TsFeature) {
+    let found = match load_runtime_file(lang, feature.runtime_filename()).is_ok() {
+        true => "Found".green(),
+        false => "Not found".red(),
+    };
+    println!("{} queries: {}", feature.short_title(), found);
+}
diff --git a/helix-term/src/lib.rs b/helix-term/src/lib.rs
index 58cb139c..fc8e934e 100644
--- a/helix-term/src/lib.rs
+++ b/helix-term/src/lib.rs
@@ -6,6 +6,7 @@ pub mod args;
 pub mod commands;
 pub mod compositor;
 pub mod config;
+pub mod health;
 pub mod job;
 pub mod keymap;
 pub mod ui;
diff --git a/helix-term/src/main.rs b/helix-term/src/main.rs
index 0f504046..cde26c2e 100644
--- a/helix-term/src/main.rs
+++ b/helix-term/src/main.rs
@@ -40,12 +40,12 @@ fn main() -> Result<()> {
 
 #[tokio::main]
 async fn main_impl() -> Result<i32> {
-    let cache_dir = helix_core::cache_dir();
-    if !cache_dir.exists() {
-        std::fs::create_dir_all(&cache_dir).ok();
+    let logpath = helix_core::log_file();
+    let parent = logpath.parent().unwrap();
+    if !parent.exists() {
+        std::fs::create_dir_all(parent).ok();
     }
 
-    let logpath = cache_dir.join("helix.log");
     let help = format!(
         "\
 {} {}
@@ -61,6 +61,8 @@ ARGS:
 FLAGS:
     -h, --help       Prints help information
     --tutor          Loads the tutorial
+    --health [LANG]  Checks for potential errors in editor setup
+                     If given, checks for config errors in language LANG
     -v               Increases logging verbosity each use for up to 3 times
                      (default file: {})
     -V, --version    Prints version information
@@ -85,12 +87,26 @@ FLAGS:
         std::process::exit(0);
     }
 
+    if args.health {
+        if let Some(lang) = args.health_arg {
+            match lang.as_str() {
+                "all" => helix_term::health::languages_all(),
+                _ => helix_term::health::language(lang),
+            }
+        } else {
+            helix_term::health::general();
+            println!();
+            helix_term::health::languages_all();
+        }
+        std::process::exit(0);
+    }
+
     let conf_dir = helix_core::config_dir();
     if !conf_dir.exists() {
         std::fs::create_dir_all(&conf_dir).ok();
     }
 
-    let config = match std::fs::read_to_string(conf_dir.join("config.toml")) {
+    let config = match std::fs::read_to_string(helix_core::config_file()) {
         Ok(config) => toml::from_str(&config)
             .map(merge_keys)
             .unwrap_or_else(|err| {