Implement 'roc format <dir_or_files>' command

cli/src/format.rs

@@ -0,0 +1,39 @@
+use std::path::PathBuf;
+
+use bumpalo::collections::String;
+use bumpalo::Bump;
+use roc_fmt::def::fmt_def;
+use roc_fmt::module::fmt_module;
+use roc_parse::{
+    module::{self, module_defs},
+    parser::{Parser, State},
+};
+use roc_reporting::user_error;
+
+pub fn format(files: Vec<PathBuf>) {
+    for file in files {
+        let arena = Bump::new();
+
+        let src = std::fs::read_to_string(&file).unwrap();
+
+        match module::parse_header(&arena, State::new(src.as_bytes())) {
+            Ok((result, state)) => {
+                let mut buf = String::new_in(&arena);
+
+                fmt_module(&mut buf, &result);
+
+                match module_defs().parse(&arena, state) {
+                    Ok((_, loc_defs, _)) => {
+                        for loc_def in loc_defs {
+                            fmt_def(&mut buf, arena.alloc(loc_def.value), 0);
+                        }
+                    }
+                    Err(error) => user_error!("Unexpected parse failure when parsing this for defs formatting:\n\n{:?}\n\nParse error was:\n\n{:?}\n\n", src, error)
+                }
+
+                std::fs::write(&file, buf).unwrap();
+            }
+            Err(error) => user_error!("Unexpected parse failure when parsing this for module header formatting:\n\n{:?}\n\nParse error was:\n\n{:?}\n\n", src, error)
+        };
+    }
+}

cli/src/lib.rs

@@ -9,14 +9,17 @@ use roc_load::file::LoadingProblem;
 use roc_mono::ir::OptLevel;
 use std::env;
 use std::io;
-use std::path::{Path, PathBuf};
+use std::path::Path;
+use std::path::PathBuf;
 use std::process;
 use std::process::Command;
 use target_lexicon::BinaryFormat;
 use target_lexicon::{Architecture, OperatingSystem, Triple, X86_32Architecture};
 
 pub mod build;
+mod format;
 pub mod repl;
+pub use format::format;
 
 pub const CMD_BUILD: &str = "build";
 pub const CMD_REPL: &str = "repl";
@@ -24,6 +27,7 @@ pub const CMD_EDIT: &str = "edit";
 pub const CMD_DOCS: &str = "docs";
 pub const CMD_CHECK: &str = "check";
 pub const CMD_VERSION: &str = "version";
+pub const CMD_FORMAT: &str = "format";
 
 pub const FLAG_DEBUG: &str = "debug";
 pub const FLAG_DEV: &str = "dev";
@@ -35,6 +39,7 @@ pub const FLAG_LINK: &str = "roc-linker";
 pub const FLAG_PRECOMPILED: &str = "precompiled-host";
 pub const FLAG_VALGRIND: &str = "valgrind";
 pub const ROC_FILE: &str = "ROC_FILE";
+pub const ROC_DIR: &str = "ROC_DIR";
 pub const BACKEND: &str = "BACKEND";
 pub const DIRECTORY_OR_FILES: &str = "DIRECTORY_OR_FILES";
 pub const ARGS_FOR_APP: &str = "ARGS_FOR_APP";
@@ -111,6 +116,14 @@ pub fn build_app<'a>() -> App<'a> {
         .subcommand(App::new(CMD_REPL)
             .about("Launch the interactive Read Eval Print Loop (REPL)")
         )
+        .subcommand(App::new(CMD_FORMAT)
+            .about("Format Roc code")
+            .arg(
+                Arg::new(DIRECTORY_OR_FILES)
+                    .index(1)
+                    .multiple_values(true)
+                    .required(false))
+        )
         .subcommand(App::new(CMD_VERSION)
             .about("Print version information")
         )

cli/src/main.rs

@@ -1,7 +1,7 @@
 use roc_cli::build::check_file;
 use roc_cli::{
-    build_app, docs, repl, BuildConfig, CMD_BUILD, CMD_CHECK, CMD_DOCS, CMD_EDIT, CMD_REPL,
+    build_app, docs, format, repl, BuildConfig, CMD_BUILD, CMD_CHECK, CMD_DOCS, CMD_EDIT,
-    CMD_VERSION, DIRECTORY_OR_FILES, FLAG_TIME, ROC_FILE,
+    CMD_FORMAT, CMD_REPL, CMD_VERSION, DIRECTORY_OR_FILES, FLAG_TIME, ROC_FILE,
 };
 use roc_load::file::LoadingProblem;
 use std::fs::{self, FileType};
@@ -125,6 +125,41 @@ fn main() -> io::Result<()> {
 
             Ok(0)
         }
+        Some(CMD_FORMAT) => {
+            let maybe_values = matches
+                .subcommand_matches(CMD_FORMAT)
+                .unwrap()
+                .values_of_os(DIRECTORY_OR_FILES);
+
+            let mut values: Vec<OsString> = Vec::new();
+
+            match maybe_values {
+                None => {
+                    let mut os_string_values: Vec<OsString> = Vec::new();
+                    read_all_roc_files(&OsStr::new("./").to_os_string(), &mut os_string_values)?;
+                    for os_string in os_string_values {
+                        values.push(os_string);
+                    }
+                }
+                Some(os_values) => {
+                    for os_str in os_values {
+                        values.push(os_str.to_os_string());
+                    }
+                }
+            }
+
+            let mut roc_files = Vec::new();
+
+            // Populate roc_files
+            for os_str in values {
+                let metadata = fs::metadata(os_str.clone())?;
+                roc_files_recursive(os_str.as_os_str(), metadata.file_type(), &mut roc_files)?;
+            }
+
+            format(roc_files);
+
+            Ok(0)
+        }
         Some(CMD_VERSION) => {
             println!("roc {}", concatcp!(include_str!("../../version.txt"), "\n"));