Refactor CLI to use clap

packages/perseus-cli/Cargo.toml

@@ -21,12 +21,13 @@ include = [
 [dependencies]
 include_dir = "0.6"
 thiserror = "1"
-anyhow = "1"
+fmterr = "0.1"
 cargo_toml = "0.9"
 indicatif = "0.17.0-beta.1" # Not stable, but otherwise error handling is just about impossible
 console = "0.14"
 serde = "1"
 serde_json = "1"
+clap = "3.0.0-beta.4"
 
 [lib]
 name = "perseus_cli"

packages/perseus-cli/src/bin/main.rs

@@ -1,7 +1,10 @@
+use clap::Clap;
+use fmterr::fmt_err;
 use perseus_cli::errors::*;
 use perseus_cli::{
-    build, check_env, delete_artifacts, delete_bad_dir, eject, export, has_ejected, help, prepare,
-    report_err, serve, PERSEUS_VERSION,
+    build, check_env, delete_artifacts, delete_bad_dir, eject, export, has_ejected,
+    parse::{Opts, Subcommand},
+    prepare, serve,
 };
 use std::env;
 use std::io::Write;
@@ -26,7 +29,10 @@ fn real_main() -> i32 {
     let dir = match dir {
         Ok(dir) => dir,
         Err(err) => {
-            report_err!(PrepError::CurrentDirUnavailable { source: err });
+            eprintln!(
+                "{}",
+                fmt_err(&PrepError::CurrentDirUnavailable { source: err })
+            );
             return 1;
         }
     };
@@ -37,11 +43,11 @@ fn real_main() -> i32 {
         // If something failed, we print the error to `stderr` and return a failure exit code
         Err(err) => {
             let should_cause_deletion = err_should_cause_deletion(&err);
-            report_err!(err);
+            eprintln!("{}", fmt_err(&err));
             // Check if the error needs us to delete a partially-formed '.perseus/' directory
             if should_cause_deletion {
                 if let Err(err) = delete_bad_dir(dir) {
-                    report_err!(err);
+                    eprintln!("{}", fmt_err(&err));
                 }
             }
             1
@@ -56,105 +62,76 @@ fn real_main() -> i32 {
 fn core(dir: PathBuf) -> Result<i32, Error> {
     // Get `stdout` so we can write warnings appropriately
     let stdout = &mut std::io::stdout();
-    // Get the arguments to this program, removing the first one (something like `perseus`)
-    let mut prog_args: Vec<String> = env::args().collect();
-    // This will panic if the first argument is not found (which is probably someone trying to fuzz us)
-    let _executable_name = prog_args.remove(0);
-    // Check the user's environment to make sure they have prerequisites
-    check_env()?;
+
     // Warn the user if they're using the CLI single-threaded mode
     if env::var("PERSEUS_CLI_SEQUENTIAL").is_ok() {
         writeln!(stdout, "Note: the Perseus CLI is running in single-threaded mode, which is less performant on most modern systems. You can switch to multi-threaded mode by unsetting the 'PERSEUS_CLI_SEQUENTIAL' environment variable. If you've deliberately enabled single-threaded mode, you can safely ignore this.\n").expect("Failed to write to stdout.");
     }
-    // Check for special arguments
-    if matches!(prog_args.get(0), Some(_)) {
-        if prog_args[0] == "-v" || prog_args[0] == "--version" {
-            writeln!(stdout, "You are currently running the Perseus CLI v{}! You can see the latest release at https://github.com/arctic-hen7/perseus/releases.", PERSEUS_VERSION).expect("Failed to write to stdout.");
-            Ok(0)
-        } else if prog_args[0] == "-h" || prog_args[0] == "--help" {
-            help(stdout);
-            Ok(0)
-        } else {
-            // Now we can check commands
-            if prog_args[0] == "build" {
-                // Set up the '.perseus/' directory if needed
-                prepare(dir.clone())?;
-                // Delete old build artifacts
+
+    // Parse the CLI options with `clap`
+    let opts: Opts = Opts::parse();
+    // Check the user's environment to make sure they have prerequisites
+    // We do this after any help pages or version numbers have been parsed for snappiness
+    check_env()?;
+    // If we're not cleaning up artifacts, create them if needed
+    if !matches!(opts.subcmd, Subcommand::Clean(_)) {
+        prepare(dir.clone())?;
+    }
+    let exit_code = match opts.subcmd {
+        Subcommand::Build(build_opts) => {
+            // Delete old build artifacts
+            delete_artifacts(dir.clone(), "static")?;
+            build(dir, build_opts)?
+        }
+        Subcommand::Export(export_opts) => {
+            // Delete old build/exportation artifacts
+            delete_artifacts(dir.clone(), "static")?;
+            delete_artifacts(dir.clone(), "exported")?;
+            export(dir, export_opts)?
+        }
+        Subcommand::Serve(serve_opts) => {
+            // Delete old build artifacts if `--no-build` wasn't specified
+            if !serve_opts.no_build {
                 delete_artifacts(dir.clone(), "static")?;
-                let exit_code = build(dir, &prog_args)?;
-                Ok(exit_code)
-            } else if prog_args[0] == "export" {
-                // Set up the '.perseus/' directory if needed
-                prepare(dir.clone())?;
-                // Delete old build/exportation artifacts
+            }
+            serve(dir, serve_opts)?
+        }
+        Subcommand::Test(test_opts) => {
+            // This will be used by the subcrates
+            env::set_var("PERSEUS_TESTING", "true");
+            // Set up the '.perseus/' directory if needed
+            prepare(dir.clone())?;
+            // Delete old build artifacts if `--no-build` wasn't specified
+            if !test_opts.no_build {
                 delete_artifacts(dir.clone(), "static")?;
+            }
+            serve(dir, test_opts)?
+        }
+        Subcommand::Clean(clean_opts) => {
+            if clean_opts.dist {
+                // The user only wants to remove distribution artifacts
+                // We don't delete `render_conf.json` because it's literally impossible for that to be the source of a problem right now
+                delete_artifacts(dir.clone(), "static")?;
+                delete_artifacts(dir.clone(), "pkg")?;
                 delete_artifacts(dir.clone(), "exported")?;
-                let exit_code = export(dir, &prog_args)?;
-                Ok(exit_code)
-            } else if prog_args[0] == "serve" {
-                // Set up the '.perseus/' directory if needed
-                prepare(dir.clone())?;
-                // Delete old build artifacts if `--no-build` wasn't specified
-                if !prog_args.contains(&"--no-build".to_string()) {
-                    delete_artifacts(dir.clone(), "static")?;
-                }
-                let exit_code = serve(dir, &prog_args)?;
-                Ok(exit_code)
-            } else if prog_args[0] == "test" {
-                // The `test` command serves in the exact same way, but it also sets `PERSEUS_TESTING`
-                // This will be used by the subcrates
-                env::set_var("PERSEUS_TESTING", "true");
-                // Set up the '.perseus/' directory if needed
-                prepare(dir.clone())?;
-                // Delete old build artifacts if `--no-build` wasn't specified
-                if !prog_args.contains(&"--no-build".to_string()) {
-                    delete_artifacts(dir.clone(), "static")?;
-                }
-                let exit_code = serve(dir, &prog_args)?;
-                Ok(exit_code)
-            } else if prog_args[0] == "prep" {
-                // This command is deliberately undocumented, it's only used for testing
-                // Set up the '.perseus/' directory if needed
-                prepare(dir)?;
-                Ok(0)
-            } else if prog_args[0] == "eject" {
-                // Set up the '.perseus/' directory if needed
-                prepare(dir.clone())?;
-                eject(dir)?;
-                Ok(0)
-            } else if prog_args[0] == "clean" {
-                if prog_args.get(1) == Some(&"--dist".to_string()) {
-                    // The user only wants to remove distribution artifacts
-                    // We don't delete `render_conf.json` because it's literally impossible for that to be the source of a problem right now
-                    delete_artifacts(dir.clone(), "static")?;
-                    delete_artifacts(dir, "pkg")?;
-                } else {
-                    // This command deletes the `.perseus/` directory completely, which musn't happen if the user has ejected
-                    if has_ejected(dir.clone()) && prog_args.get(1) != Some(&"--force".to_string())
-                    {
-                        return Err(EjectionError::CleanAfterEject.into());
-                    }
-                    // Just delete the '.perseus/' directory directly, as we'd do in a corruption
-                    delete_bad_dir(dir)?;
-                }
-
-                Ok(0)
             } else {
-                writeln!(
-                    stdout,
-                    "Unknown command '{}'. You can see the help page with -h/--help.",
-                    prog_args[0]
-                )
-                .expect("Failed to write to stdout.");
-                Ok(1)
+                // This command deletes the `.perseus/` directory completely, which musn't happen if the user has ejected
+                if has_ejected(dir.clone()) && !clean_opts.force {
+                    return Err(EjectionError::CleanAfterEject.into());
+                }
+                // Just delete the '.perseus/' directory directly, as we'd do in a corruption
+                delete_bad_dir(dir)?;
             }
+            0
         }
-    } else {
-        writeln!(
-            stdout,
-            "Please provide a command to run, or use -h/--help to see the help page."
-        )
-        .expect("Failed to write to stdout.");
-        Ok(1)
-    }
+        Subcommand::Eject => {
+            eject(dir)?;
+            0
+        }
+        Subcommand::Prep => {
+            // The `.perseus/` directory has already been set up in the preliminaries, so we don't need to do anything here
+            0
+        }
+    };
+    Ok(exit_code)
 }

packages/perseus-cli/src/build.rs

@@ -1,5 +1,6 @@
 use crate::cmd::{cfg_spinner, run_stage};
 use crate::errors::*;
+use crate::parse::BuildOpts;
 use crate::thread::{spawn_thread, ThreadHandle};
 use console::{style, Emoji};
 use indicatif::{MultiProgress, ProgressBar};
@@ -107,7 +108,7 @@ pub fn build_internal(
 }
 
 /// Builds the subcrates to get a directory that we can serve. Returns an exit code.
-pub fn build(dir: PathBuf, _prog_args: &[String]) -> Result<i32, ExecutionError> {
+pub fn build(dir: PathBuf, _opts: BuildOpts) -> Result<i32, ExecutionError> {
     let spinners = MultiProgress::new();
 
     let (sg_thread, wb_thread) = build_internal(dir.clone(), &spinners, 2)?;

packages/perseus-cli/src/errors.rs

@@ -153,13 +153,3 @@ pub enum ExportError {
     #[error(transparent)]
     ExecutionError(#[from] ExecutionError),
 }
-
-/// Reports the given error to the user with `anyhow`.
-#[macro_export]
-macro_rules! report_err {
-    ($err:expr) => {
-        let err = ::anyhow::anyhow!($err);
-        // This will include a `Caused by` section
-        eprintln!("Error: {:?}", err);
-    };
-}

packages/perseus-cli/src/export.rs

@@ -1,5 +1,6 @@
 use crate::cmd::{cfg_spinner, run_stage};
 use crate::errors::*;
+use crate::parse::ExportOpts;
 use crate::thread::{spawn_thread, ThreadHandle};
 use console::{style, Emoji};
 use indicatif::{MultiProgress, ProgressBar};
@@ -191,7 +192,7 @@ pub fn export_internal(
 }
 
 /// Builds the subcrates to get a directory that we can serve. Returns an exit code.
-pub fn export(dir: PathBuf, _prog_args: &[String]) -> Result<i32, ExportError> {
+pub fn export(dir: PathBuf, _opts: ExportOpts) -> Result<i32, ExportError> {
     let spinners = MultiProgress::new();
 
     let (ep_thread, wb_thread) = export_internal(dir.clone(), &spinners, 2)?;

packages/perseus-cli/src/lib.rs

@@ -32,7 +32,8 @@ mod cmd;
 mod eject;
 pub mod errors;
 mod export;
-mod help;
+/// Parsing utilities for arguments.
+pub mod parse;
 mod prepare;
 mod serve;
 mod thread;
@@ -48,7 +49,6 @@ pub const PERSEUS_VERSION: &str = env!("CARGO_PKG_VERSION");
 pub use build::build;
 pub use eject::{eject, has_ejected};
 pub use export::export;
-pub use help::help;
 pub use prepare::{check_env, prepare};
 pub use serve::serve;
 

packages/perseus-cli/src/parse.rs

@@ -0,0 +1,66 @@
+#![allow(missing_docs)] // Prevents double-documenting some things
+
+use crate::PERSEUS_VERSION;
+use clap::{AppSettings, Clap};
+
+// The documentation for the `Opts` struct will appear in the help page, hence the lack of puncutation and the lowercasing in places
+
+/// The command-line interface for Perseus, a super-fast WebAssembly frontend development framework!
+#[derive(Clap)]
+#[clap(version = PERSEUS_VERSION)]
+#[clap(setting = AppSettings::ColoredHelp)]
+pub struct Opts {
+    #[clap(subcommand)]
+    pub subcmd: Subcommand,
+}
+
+#[derive(Clap)]
+pub enum Subcommand {
+    Build(BuildOpts),
+    Export(ExportOpts),
+    Serve(ServeOpts),
+    /// Serves your app as `perseus serve` does, but puts it in testing mode
+    Test(ServeOpts),
+    Clean(CleanOpts),
+    /// Ejects you from the CLI harness, enabling you to work with the internals of Perseus
+    Eject,
+    /// Prepares the `.perseus/` directory (done automatically by `build` and `serve`)
+    Prep,
+}
+/// Builds your app
+#[derive(Clap)]
+pub struct BuildOpts {
+    /// Build for production
+    #[clap(long)]
+    release: bool,
+}
+/// Exports your app to purely static files
+#[derive(Clap)]
+pub struct ExportOpts {
+    /// Export for production
+    #[clap(long)]
+    release: bool,
+}
+/// Serves your app (set the `$HOST` and `$PORT` environment variables to change the location it's served at)
+#[derive(Clap)]
+pub struct ServeOpts {
+    /// Don't run the final binary, but print its location instead as the last line of output
+    #[clap(long)]
+    pub no_run: bool,
+    /// Only build the server, and use the results of a previous `perseus build`
+    #[clap(long)]
+    pub no_build: bool,
+    /// Build and serve for production
+    #[clap(long)]
+    release: bool,
+}
+/// Removes `.perseus/` entirely for updates or to fix corruptions
+#[derive(Clap)]
+pub struct CleanOpts {
+    /// Only remove the `.perseus/dist/` folder (use if you've ejected)
+    #[clap(short, long)]
+    pub dist: bool,
+    /// Remove the directory, even if you've ejected (this will permanently destroy any changes you've made to `.perseus/`!)
+    #[clap(short, long)]
+    pub force: bool,
+}