Merge pull request #12 from vrmiguel/oof-argparsing

Change argparsing lib

Cargo.toml

@@ -4,28 +4,33 @@ version = "0.1.4"
 authors = ["Vinícius Rodrigues Miguel <vrmiguel99@gmail.com>", "João M. Bezerra <marcospb19@hotmail.com>"]
 edition = "2018"
 readme = "README.md"
-homepage = "https://github.com/vrmiguel/ouch"
 repository = "https://github.com/vrmiguel/ouch"
 license = "MIT"
 keywords = ["decompression", "compression", "zip", "tar", "gzip"]
 categories = ["command-line-utilities", "compression", "encoding"]
 description = "A command-line utility for easily compressing and decompressing files and directories."
 
-
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
 colored = "2.0.0"
 walkdir = "2.3.2"
-clap    = "2.33.3"
 tar     = "0.4.33"
 xz2     = "0.1.6"
 bzip2   = "0.4.2"
 flate2  = "1.0.14"
 zip     = "0.5.11"
 
+# Dependency from workspace
+oof = { path = "./oof" }
 
 [profile.release]
 lto = true
 codegen-units = 1
 opt-level = 3
+
+[workspace]
+members = [
+    ".",
+    "oof",
+]

oof/Cargo.toml

@@ -0,0 +1,9 @@
+[package]
+name = "oof"
+version = "0.1.0"
+authors = ["João M. Bezerra <marcospb19@hotmail.com>"]
+edition = "2018"
+description = "Ouch's argparsing library"
+repository = "https://github.com/vrmiguel/ouch"
+
+[dependencies]

oof/src/error.rs

@@ -0,0 +1,35 @@
+use std::{error, ffi::OsString, fmt};
+
+use crate::Flag;
+
+#[derive(Debug)]
+pub enum OofError {
+    FlagValueConflict {
+        flag: Flag,
+        previous_value: OsString,
+        new_value: OsString,
+    },
+}
+
+impl error::Error for OofError {
+    fn source(&self) -> Option<&(dyn error::Error + 'static)> {
+        None
+    }
+}
+
+impl fmt::Display for OofError {
+    fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
+        // TODO: implement proper debug messages
+        match self {
+            OofError::FlagValueConflict {
+                flag,
+                previous_value,
+                new_value,
+            } => write!(
+                f,
+                "CLI flag value conflicted for flag '--{}', previous: {:?}, new: {:?}.",
+                flag.long, previous_value, new_value
+            ),
+        }
+    }
+}

oof/src/flags.rs

@@ -0,0 +1,110 @@
+use std::{
+    collections::{BTreeMap, BTreeSet},
+    ffi::{OsStr, OsString},
+};
+
+/// Shallow type, created to indicate a `Flag` that accepts a argument.
+///
+/// ArgFlag::long(), is actually a Flag::long(), but sets a internal attribute.
+///
+/// Examples in here pls
+#[derive(Debug)]
+pub struct ArgFlag;
+
+impl ArgFlag {
+    pub fn long(name: &'static str) -> Flag {
+        Flag {
+            long: name,
+            short: None,
+            takes_value: true,
+        }
+    }
+}
+
+#[derive(Debug, PartialEq, Clone)]
+pub struct Flag {
+    // Also the name
+    pub long: &'static str,
+    pub short: Option<char>,
+    pub takes_value: bool,
+}
+
+impl Flag {
+    pub fn long(name: &'static str) -> Self {
+        Self {
+            long: name,
+            short: None,
+            takes_value: false,
+        }
+    }
+
+    pub fn short(mut self, short_flag_char: char) -> Self {
+        self.short = Some(short_flag_char);
+        self
+    }
+}
+
+#[derive(Default, PartialEq, Eq, Debug)]
+pub struct Flags {
+    pub boolean_flags: BTreeSet<&'static str>,
+    pub argument_flags: BTreeMap<&'static str, OsString>,
+}
+
+impl Flags {
+    pub fn new() -> Self {
+        Self::default()
+    }
+}
+
+impl Flags {
+    pub fn is_present(&self, flag_name: &str) -> bool {
+        self.boolean_flags.contains(flag_name) || self.argument_flags.contains_key(flag_name)
+    }
+
+    pub fn arg(&self, flag_name: &str) -> Option<&OsString> {
+        self.argument_flags.get(flag_name)
+    }
+
+    pub fn take_arg(&mut self, flag_name: &str) -> Option<OsString> {
+        self.argument_flags.remove(flag_name)
+    }
+}
+
+#[derive(Debug)]
+pub enum FlagType {
+    None,
+    Short,
+    Long,
+}
+
+impl FlagType {
+    pub fn from(text: impl AsRef<OsStr>) -> Self {
+        let text = text.as_ref();
+
+        let mut iter;
+
+        #[cfg(target_family = "unix")]
+        {
+            use std::os::unix::ffi::OsStrExt;
+            iter = text.as_bytes().iter();
+        }
+        #[cfg(target_family = "windows")]
+        {
+            use std::os::windows::ffi::OsStrExt;
+            iter = text.encode_wide
+        }
+
+        // 45 is the code for a hyphen
+        // Typed as 45_u16 for Windows
+        // Typed as 45_u8 for Unix
+        if let Some(45) = iter.next() {
+            if let Some(45) = iter.next() {
+                Self::Long
+            } else {
+                Self::Short
+            }
+        } else {
+            Self::None
+        }
+    }
+}

oof/src/lib.rs

@@ -0,0 +1,371 @@
+//! Ouch's argparsing crate.
+//!
+//! The usage of this crate is heavily based on boolean_flags and
+//! argument_flags, there should be an more _obvious_ naming.
+
+mod error;
+mod flags;
+pub mod util;
+
+use std::{
+    collections::BTreeMap,
+    ffi::{OsStr, OsString},
+};
+
+pub use error::OofError;
+pub use flags::{ArgFlag, Flag, FlagType, Flags};
+use util::trim_double_hyphen;
+
+/// Pop leading application `subcommand`, if valid.
+///
+/// `args` can be a Vec of `OsString` or `OsStr`
+/// `subcommands` is any container that can yield `&str` through `AsRef`, can be `Vec<&str>` or
+/// a GREAT `BTreeSet<String>` (or `BTreeSet<&str>`).
+pub fn pop_subcommand<'a, T, I, II>(args: &mut Vec<T>, subcommands: I) -> Option<&'a II>
+where
+    I: IntoIterator<Item = &'a II>,
+    II: AsRef<str>,
+    T: AsRef<OsStr>,
+{
+    if args.is_empty() {
+        return None;
+    }
+
+    for subcommand in subcommands.into_iter() {
+        if subcommand.as_ref() == args[0].as_ref() {
+            args.remove(0);
+            return Some(subcommand);
+        }
+    }
+
+    None
+}
+
+/// Detect flags from args and filter from args.
+///
+/// Each flag received via flags_info should must have unique long and short identifiers.
+///
+/// # Panics (Developer errors)
+/// - If there are duplicated short flag identifiers.
+/// - If there are duplicated long flag identifiers.
+///
+/// Both conditions cause panic because your program's flags specification is meant to have unique
+/// flags. There shouldn't be two "--verbose" flags, for example.
+/// Caller should guarantee it, fortunately, this can almost always be caught while prototyping in
+/// debug mode, test your CLI flags once, if it works once, you're good,
+///
+/// # Errors (User errors)
+/// - Argument flag comes at last arg, so there's no way to provide an argument.
+///     - Or if it doesn't comes at last, but the rest are just flags, no possible and valid arg.
+/// - Short flags with multiple letters in the same arg contain a argument flag that does not come
+/// as the last one in the list (example "-oahc", where 'o', 'a', or 'h' is a argument flag, but do
+/// not comes at last, so it is impossible for them to receive the required argument.
+/// - User passes same flag twice (short or long, boolean or arg).
+///
+/// ...
+pub fn filter_flags(
+    args: Vec<OsString>,
+    flags_info: &[Flag],
+) -> Result<(Vec<OsString>, Flags), OofError> {
+    let mut short_flags_info = BTreeMap::<char, &Flag>::new();
+    let mut long_flags_info = BTreeMap::<&'static str, &Flag>::new();
+
+    for flag in flags_info.iter() {
+        // Panics if duplicated/conflicts
+        assert!(
+            !long_flags_info.contains_key(flag.long),
+            "DEV ERROR: duplicated long flag '{}'.",
+            flag.long
+        );
+
+        long_flags_info.insert(flag.long, &flag);
+
+        if let Some(short) = flag.short {
+            // Panics if duplicated/conflicts
+            assert!(
+                !short_flags_info.contains_key(&short),
+                "DEV ERROR: duplicated short flag '-{}'.",
+                short
+            );
+            short_flags_info.insert(short, &flag);
+        }
+    }
+
+    // Consume args, filter out flags, and add back to args new vec
+    let mut iter = args.into_iter();
+    let mut new_args = vec![];
+    let mut result_flags = Flags::new();
+
+    while let Some(arg) = iter.next() {
+        let flag_type = FlagType::from(&arg);
+
+        // If it isn't a flag, retrieve to `args` and skip this iteration
+        if let FlagType::None = flag_type {
+            new_args.push(arg);
+            continue;
+        }
+
+        // If it is a flag, now we try to interpret as valid utf-8
+        let flag: &str = arg
+            .to_str()
+            .unwrap_or_else(|| panic!("User error: The flag needs to be valid utf8"));
+
+        // Only one hyphen in the flag
+        // A short flag can be of form "-", "-abcd", "-h", "-v", etc
+        if let FlagType::Short = flag_type {
+            assert_eq!(flag.chars().next(), Some('-'));
+
+            // TODO
+            // TODO: what should happen if the flag is empty?????
+            // if flags.chars().skip(1).next().is_none() {
+            //     panic!("User error: flag is empty???");
+            // }
+
+            // Skip hyphen and get all letters
+            let letters = flag.chars().skip(1).collect::<Vec<char>>();
+
+            // For each letter in the short arg, except the last one
+            for (i, letter) in letters.iter().copied().enumerate() {
+                // Safety: this loop only runs when len >= 1
+                let is_last_letter = i == letters.len() - 1;
+
+                let flag_info = short_flags_info.get(&letter).unwrap_or_else(|| {
+                    panic!("User error: Unexpected/UNKNOWN flag `letter`, error")
+                });
+
+                if !is_last_letter && flag_info.takes_value {
+                    panic!("User error: Only the last letter can refer to flag that takes values");
+                    // Because "-AB argument" only works if B takes values, not A.
+                    // That is, the short flag that takes values need to come at the end
+                    // of this piece of text
+                }
+
+                let flag_name: &'static str = flag_info.long;
+
+                if flag_info.takes_value {
+                    // If it was already inserted
+                    if result_flags.argument_flags.contains_key(flag_name) {
+                        panic!("User error: duplicated, found this flag TWICE!");
+                    }
+
+                    // pop the next one
+                    let flag_argument = iter.next();
+                    flag_argument.unwrap_or_else(|| {
+                        panic!(
+                            "USer errror: argument flag `argument_flag` came at last, but it \
+                             requires an argument"
+                        )
+                    });
+
+                    // Otherwise, insert it (TODO: grab next one and add it)
+                    // result_flags.argument_flags.insert(flag_info.long);
+                } else {
+                    // If it was already inserted
+                    if result_flags.boolean_flags.contains(flag_name) {
+                        panic!("User error: duplicated, found this flag TWICE!");
+                    }
+                    // Otherwise, insert it
+                    result_flags.boolean_flags.insert(flag_name);
+                }
+            }
+        }
+
+        if let FlagType::Long = flag_type {
+            let flag = trim_double_hyphen(flag);
+
+            let flag_info = long_flags_info.get(flag).unwrap_or_else(|| {
+                panic!("User error: Unexpected/UNKNOWN flag '{}'", flag);
+            });
+
+            let flag_name = flag_info.long;
+
+            if flag_info.takes_value {
+                // If it was already inserted
+                if result_flags.argument_flags.contains_key(&flag_name) {
+                    panic!("User error: duplicated, found this flag TWICE!");
+                }
+
+                let flag_argument = iter.next().unwrap_or_else(|| {
+                    panic!(
+                        "USer errror: argument flag `argument_flag` came at last, but it requires \
+                         an argument"
+                    )
+                });
+                result_flags.argument_flags.insert(flag_name, flag_argument);
+            } else {
+                // If it was already inserted
+                if result_flags.boolean_flags.contains(&flag_name) {
+                    panic!("User error: duplicated, found this flag TWICE!");
+                }
+                // Otherwise, insert it
+                result_flags.boolean_flags.insert(&flag_name);
+            }
+
+            // // TODO
+            // TODO: what should happen if the flag is empty?????
+            // if flag.is_empty() {
+            //     panic!("Is this an error?");
+            // }
+        }
+    }
+
+    Ok((new_args, result_flags))
+}
+
+/// Says if any text matches any arg
+pub fn matches_any_arg<T, U>(args: &[T], texts: &[U]) -> bool
+where
+    T: AsRef<OsStr>,
+    U: AsRef<str>,
+{
+    texts
+        .iter()
+        .any(|text| args.iter().any(|arg| arg.as_ref() == text.as_ref()))
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::*;
+
+    fn gen_args(text: &str) -> Vec<OsString> {
+        let args = text.split_whitespace();
+        args.map(OsString::from).collect()
+    }
+
+    // asdasdsa
+    #[test]
+    fn test_filter_flags() {
+        let flags_info = [
+            ArgFlag::long("output_file").short('o'),
+            Flag::long("verbose").short('v'),
+            Flag::long("help").short('h'),
+        ];
+        let args = gen_args("ouch a.zip -v b.tar.gz --output_file new_folder c.tar");
+
+        let (args, mut flags) = filter_flags(args, &flags_info).unwrap();
+
+        assert_eq!(args, gen_args("ouch a.zip b.tar.gz c.tar"));
+        assert!(flags.is_present("output_file"));
+        assert_eq!(
+            Some(&OsString::from("new_folder")),
+            flags.arg("output_file")
+        );
+        assert_eq!(
+            Some(OsString::from("new_folder")),
+            flags.take_arg("output_file")
+        );
+        assert!(!flags.is_present("output_file"));
+    }
+
+    #[test]
+    fn test_pop_subcommand() {
+        let subcommands = &["commit", "add", "push", "remote"];
+        let mut args = gen_args("add a b c");
+
+        let result = pop_subcommand(&mut args, subcommands);
+
+        assert_eq!(result, Some(&"add"));
+        assert_eq!(args[0], "a");
+
+        // Check when no subcommand matches
+        let mut args = gen_args("a b c");
+        let result = pop_subcommand(&mut args, subcommands);
+
+        assert_eq!(result, None);
+        assert_eq!(args[0], "a");
+    }
+
+    // #[test]
+    // fn test_flag_info_macros() {
+    //     let flags_info = [
+    //         arg_flag!('o', "output_file"),
+    //         arg_flag!("delay"),
+    //         flag!('v', "verbose"),
+    //         flag!('h', "help"),
+    //         flag!("version"),
+    //     ];
+
+    //     let expected = [
+    //         ArgFlag::long("output_file").short('o'),
+    //         ArgFlag::long("delay"),
+    //         Flag::long("verbose").short('v'),
+    //         Flag::long("help").short('h'),
+    //         Flag::long("version"),
+    //     ];
+
+    //     assert_eq!(flags_info, expected);
+    // }
+
+    #[test]
+    // TODO: remove should_panic and use proper error handling inside of filter_args
+    #[should_panic]
+    fn test_flag_info_with_long_flag_conflict() {
+        let flags_info = [
+            ArgFlag::long("verbose").short('a'),
+            Flag::long("verbose").short('b'),
+        ];
+
+        // Should panic here
+        let result = filter_flags(vec![], &flags_info);
+        assert!(matches!(result, Err(OofError::FlagValueConflict { .. })));
+    }
+
+    #[test]
+    // TODO: remove should_panic and use proper error handling inside of filter_args
+    #[should_panic]
+    fn test_flag_info_with_short_flag_conflict() {
+        let flags_info = [
+            ArgFlag::long("output_file").short('o'),
+            Flag::long("verbose").short('o'),
+        ];
+
+        // Should panic here
+        filter_flags(vec![], &flags_info).unwrap_err();
+    }
+
+    #[test]
+    fn test_matches_any_arg_function() {
+        let args = gen_args("program a -h b");
+        assert!(matches_any_arg(&args, &["--help", "-h"]));
+
+        let args = gen_args("program a b --help");
+        assert!(matches_any_arg(&args, &["--help", "-h"]));
+
+        let args = gen_args("--version program a b");
+        assert!(matches_any_arg(&args, &["--version", "-v"]));
+
+        let args = gen_args("program -v a --version b");
+        assert!(matches_any_arg(&args, &["--version", "-v"]));
+
+        // Cases without it
+        let args = gen_args("program a b c");
+        assert!(!matches_any_arg(&args, &["--help", "-h"]));
+
+        let args = gen_args("program a --version -v b c");
+        assert!(!matches_any_arg(&args, &["--help", "-h"]));
+    }
+}
+
+/// Create a flag with long flag (?).
+#[macro_export]
+macro_rules! flag {
+    ($short:expr, $long:expr) => {{
+        oof::Flag::long($long).short($short)
+    }};
+
+    ($long:expr) => {{
+        oof::Flag::long($long)
+    }};
+}
+
+/// Create a flag with long flag (?), receives argument (?).
+#[macro_export]
+macro_rules! arg_flag {
+    ($short:expr, $long:expr) => {{
+        oof::ArgFlag::long($long).short($short)
+    }};
+
+    ($long:expr) => {{
+        oof::ArgFlag::long($long)
+    }};
+}

oof/src/util.rs

@@ -0,0 +1,14 @@
+/// Util function to skip the two leading long flag hyphens.
+pub fn trim_double_hyphen(flag_text: &str) -> &str {
+    let mut chars = flag_text.chars();
+    chars.nth(1); // Skipping 2 chars
+    chars.as_str()
+}
+
+/// Util function to skip the single leading short flag hyphen.
+pub fn trim_single_hyphen(flag_text: &str) -> &str {
+    let mut chars = flag_text.chars();
+
+    chars.next(); // Skipping 1 char
+    chars.as_str()
+}

src/cli.rs

@@ -1,212 +1,199 @@
-use std::{
-    convert::TryFrom,
-    fs,
-    path::{Path, PathBuf},
-    vec::Vec,
-};
+use std::{env, ffi::OsString, io, path::PathBuf, vec::Vec};
 
-use clap::{Arg, Values};
-use colored::Colorize;
-
-use crate::{extension::Extension, file::File};
+use oof::{arg_flag, flag};
 
 #[derive(PartialEq, Eq, Debug)]
-pub enum CommandKind {
-    Compression(
-        /// Files to be compressed
-        Vec<PathBuf>,
-    ),
-    Decompression(
-        /// Files to be decompressed and their extensions
-        Vec<File>,
-    ),
-}
-
-#[derive(PartialEq, Eq, Copy, Clone, Debug)]
-pub enum Flags {
-    // No flags supplied
-    None,
-    // Flag -y, --yes supplied
-    AlwaysYes,
-    // Flag -n, --no supplied
-    AlwaysNo,
+pub enum Command {
+    /// Files to be compressed
+    Compress {
+        files: Vec<PathBuf>,
+        compressed_output_path: PathBuf,
+    },
+    /// Files to be decompressed and their extensions
+    Decompress {
+        files: Vec<PathBuf>,
+        output_folder: Option<PathBuf>,
+    },
+    ShowHelp,
+    ShowVersion,
 }
 
 #[derive(PartialEq, Eq, Debug)]
-pub struct Command {
-    pub kind: CommandKind,
-    pub output: Option<File>,
+pub struct CommandInfo {
+    pub command: Command,
+    pub flags: oof::Flags,
+    // pub config: Config, // From .TOML, maybe, in the future
 }
 
-pub fn clap_app<'a, 'b>() -> clap::App<'a, 'b> {
-    clap::App::new("ouch")
-        .version("0.1.4")
-        .about("ouch is a unified compression & decompression utility")
-        .after_help(
-"ouch infers what to based on the extensions of the input files and output file received.
-Examples: `ouch -i movies.tar.gz classes.zip -o Videos/` in order to decompress files into a folder.
-          `ouch -i headers/ sources/ Makefile -o my-project.tar.gz`
-          `ouch -i image{1..50}.jpeg -o images.zip`
-Please relate any issues or contribute at https://github.com/vrmiguel/ouch")
-        .author("Vinícius R. Miguel")
-        .help_message("Displays this message and exits")
-        .settings(&[
-            clap::AppSettings::ColoredHelp,
-            clap::AppSettings::ArgRequiredElseHelp,
-        ])
-        .arg(
-            Arg::with_name("input")
-                .required(true)
-                .multiple(true)
-                .long("input")
-                .short("i")
-                .help("The input files or directories.")
-                .takes_value(true),
-        )
-        .arg(
-            Arg::with_name("output")
-                // --output/-o not required when output can be inferred from the input files
-                .required(false)
-                .multiple(false)
-                .long("output")
-                .short("o")
-                .help("The output directory or compressed file.")
-                .takes_value(true),
-        )
-        .arg(
-            Arg::with_name("yes")
-                .required(false)
-                .multiple(false)
-                .long("yes")
-                .short("y")
-                .help("Says yes to all confirmation dialogs.")
-                .conflicts_with("no")
-                .takes_value(false),
-        )
-        .arg(
-            Arg::with_name("no")
-                .required(false)
-                .multiple(false)
-                .long("no")
-                .short("n")
-                .help("Says no to all confirmation dialogs.")
-                .conflicts_with("yes")
-                .takes_value(false),
-        )
+/// Calls parse_args_and_flags_from using std::env::args_os ( argv )
+pub fn parse_args() -> crate::Result<ParsedArgs> {
+    let args = env::args_os().skip(1).collect();
+    parse_args_from(args)
 }
 
-pub fn get_matches() -> clap::ArgMatches<'static> {
-    clap_app().get_matches()
+pub struct ParsedArgs {
+    pub command: Command,
+    pub flags: oof::Flags,
+    // pub program_called: OsString, // Useful?
 }
 
-pub fn parse_matches(matches: clap::ArgMatches<'static>) -> crate::Result<(Command, Flags)> {
-    let flag = match (matches.is_present("yes"), matches.is_present("no")) {
-        (true, true) => unreachable!(),
-        (true, _) => Flags::AlwaysYes,
-        (_, true) => Flags::AlwaysNo,
-        (_, _) => Flags::None,
+fn canonicalize_files(files: Vec<PathBuf>) -> io::Result<Vec<PathBuf>> {
+    files.into_iter().map(|path| path.canonicalize()).collect()
+}
+
+pub fn parse_args_from(mut args: Vec<OsString>) -> crate::Result<ParsedArgs> {
+    if oof::matches_any_arg(&args, &["--help", "-h"]) || args.is_empty() {
+        return Ok(ParsedArgs {
+            command: Command::ShowHelp,
+            flags: oof::Flags::default(),
+        });
+    }
+
+    if oof::matches_any_arg(&args, &["--version"]) {
+        return Ok(ParsedArgs {
+            command: Command::ShowVersion,
+            flags: oof::Flags::default(),
+        });
+    }
+
+    let subcommands = &["compress"];
+
+    let mut flags_info = vec![flag!('y', "yes"), flag!('n', "no")];
+
+    let parsed_args = match oof::pop_subcommand(&mut args, subcommands) {
+        Some(&"compress") => {
+            let (args, flags) = oof::filter_flags(args, &flags_info)?;
+            let mut files: Vec<PathBuf> = args.into_iter().map(PathBuf::from).collect();
+
+            if files.len() < 2 {
+                panic!("The compress subcommands demands at least 2 arguments, see usage:.......");
+            }
+            // Safety: we checked that args.len() >= 2
+            let compressed_output_path = files.pop().unwrap();
+
+            let files = canonicalize_files(files)?;
+
+            let command = Command::Compress {
+                files,
+                compressed_output_path,
+            };
+            ParsedArgs { command, flags }
+        }
+        // Defaults to decompression when there is no subcommand
+        None => {
+            flags_info.push(arg_flag!('o', "output"));
+
+            // Parse flags
+            let (args, mut flags) = oof::filter_flags(args, &flags_info)?;
+
+            let files: Vec<_> = args.into_iter().map(PathBuf::from).collect();
+            let output_folder = flags.take_arg("output").map(PathBuf::from);
+
+            // Is the output here fully correct?
+            // With the paths not canonicalized?
+
+            let command = Command::Decompress {
+                files,
+                output_folder,
+            };
+            ParsedArgs { command, flags }
+        }
+        _ => unreachable!("You should match each subcommand passed."),
     };
 
-    Ok((Command::try_from(matches)?, flag))
+    Ok(parsed_args)
 }
 
-impl TryFrom<clap::ArgMatches<'static>> for Command {
-    type Error = crate::Error;
+#[cfg(test)]
+mod tests {
+    use super::*;
 
-    fn try_from(matches: clap::ArgMatches<'static>) -> crate::Result<Command> {
-        let process_decompressible_input = |input_files: Values| {
-            let input_files =
-                input_files.map(|filename| (Path::new(filename), Extension::new(filename)));
-
-            for file in input_files.clone() {
-                match file {
-                    (filename, Ok(_)) => {
-                        let path = Path::new(filename);
-                        if !path.exists() {
-                            return Err(crate::Error::FileNotFound(filename.into()));
-                        }
-                    }
-                    (filename, Err(_)) => {
-                        return Err(crate::Error::InputsMustHaveBeenDecompressible(
-                            filename.into(),
-                        ));
-                    }
-                }
-            }
-
-            Ok(input_files
-                .map(|(filename, extension)| {
-                    (fs::canonicalize(filename).unwrap(), extension.unwrap())
-                })
-                .map(File::from)
-                .collect::<Vec<_>>())
-        };
-
-        // Possibilities:
-        //   * Case 1: output not supplied, therefore try to infer output by checking if all input files are decompressible
-        //   * Case 2: output supplied
-
-        let output_was_supplied = matches.is_present("output");
-
-        let input_files = matches.values_of("input").unwrap(); // Safe to unwrap since input is an obligatory argument
-
-        if output_was_supplied {
-            let output_file = matches.value_of("output").unwrap(); // Safe unwrap since we've established that output was supplied
-
-            let output_file_extension = Extension::new(output_file);
-
-            let output_is_compressible = output_file_extension.is_ok();
-            if output_is_compressible {
-                // The supplied output is compressible, so we'll compress our inputs to it
-
-                let canonical_paths = input_files.clone().map(Path::new).map(fs::canonicalize);
-                for (filename, canonical_path) in input_files.zip(canonical_paths.clone()) {
-                    if let Err(err) = canonical_path {
-                        let path = PathBuf::from(filename);
-                        if !path.exists() {
-                            return Err(crate::Error::FileNotFound(path));
-                        }
-
-                        eprintln!("{} {}", "[ERROR]".red(), err);
-                        return Err(crate::Error::IoError);
-                    }
-                }
-
-                let input_files = canonical_paths.map(Result::unwrap).collect();
-
-                Ok(Command {
-                    kind: CommandKind::Compression(input_files),
-                    output: Some(File {
-                        path: output_file.into(),
-                        contents_in_memory: None,
-                        extension: Some(output_file_extension.unwrap()),
-                    }),
-                })
-            } else {
-                // Output not supplied
-                // Checking if input files are decompressible
-
-                let input_files = process_decompressible_input(input_files)?;
-
-                Ok(Command {
-                    kind: CommandKind::Decompression(input_files),
-                    output: Some(File {
-                        path: output_file.into(),
-                        contents_in_memory: None,
-                        extension: None,
-                    }),
-                })
-            }
-        } else {
-            // else: output file not supplied
-            // Case 1: all input files are decompressible
-            // Case 2: error
-            let input_files = process_decompressible_input(input_files)?;
-
-            Ok(Command {
-                kind: CommandKind::Decompression(input_files),
-                output: None,
-            })
-        }
+    fn gen_args(text: &str) -> Vec<OsString> {
+        let args = text.split_whitespace();
+        args.map(OsString::from).collect()
     }
+
+    // // util for test the argument parsing
+    // macro_rules! test {
+    //     ($expected_command:expr, $input_text:expr) => {{
+    //         assert_eq!(
+    //             $expected_command,
+    //             oof::try_arg_parsing($input_text.split_whitespace())
+    //         )
+    //     }};
+    // }
+
+    macro_rules! parse {
+        ($input_text:expr) => {{
+            let args = gen_args($input_text);
+            parse_args_from(args).unwrap()
+        }};
+    }
+
+    #[test]
+    // The absolute flags that ignore all the other argparsing rules are --help and --version
+    fn test_absolute_flags() {
+        let expected = Command::ShowHelp;
+        assert_eq!(expected, parse!("").command);
+        assert_eq!(expected, parse!("-h").command);
+        assert_eq!(expected, parse!("--help").command);
+        assert_eq!(expected, parse!("aaaaaaaa --help -o -e aaa").command);
+        assert_eq!(expected, parse!("aaaaaaaa -h").command);
+        assert_eq!(expected, parse!("--help compress aaaaaaaa").command);
+        assert_eq!(expected, parse!("compress --help").command);
+        assert_eq!(expected, parse!("--version --help").command);
+        assert_eq!(expected, parse!("aaaaaaaa -v aaaa -h").command);
+
+        let expected = Command::ShowVersion;
+        assert_eq!(expected, parse!("ouch --version").command);
+        assert_eq!(expected, parse!("ouch a --version b").command);
+    }
+
+    #[test]
+    fn test_arg_parsing_compress_subcommand() {
+        let files = ["a", "b", "c"].iter().map(PathBuf::from).collect();
+
+        let expected = Command::Compress {
+            files,
+            compressed_output_path: "d".into(),
+        };
+        assert_eq!(expected, parse!("compress a b c d").command);
+    }
+
+    #[test]
+    fn test_arg_parsing_decompress_subcommand() {
+        let files: Vec<_> = ["a", "b", "c"].iter().map(PathBuf::from).collect();
+
+        let expected = Command::Decompress {
+            files: files.clone(),
+            output_folder: None,
+        };
+        assert_eq!(expected, parse!("a b c").command);
+
+        let expected = Command::Decompress {
+            files,
+            output_folder: Some("folder".into()),
+        };
+        assert_eq!(expected, parse!("a b c --output folder").command);
+        assert_eq!(expected, parse!("a b --output folder c").command);
+        assert_eq!(expected, parse!("a --output folder b c").command);
+        assert_eq!(expected, parse!("--output folder a b c").command);
+    }
+
+    // #[test]
+    // fn test_arg_parsing_decompress_subcommand() {
+    //     let files: Vec<PathBuf> = ["a", "b", "c"].iter().map(PathBuf::from).collect();
+
+    //     let expected = Ok(Command::Decompress {
+    //         files: files.clone(),
+    //     });
+    //     test!(expected, "ouch a b c");
+
+    //     let files: Vec<PathBuf> = ["a", "b", "c", "d"].iter().map(PathBuf::from).collect();
+
+    //     let expected = Ok(Command::Decompress {
+    //         files: files.clone(),
+    //     });
+    //     test!(expected, "ouch a b c d");
+    // }
 }

src/compressors/compressor.rs

@@ -8,9 +8,9 @@ use crate::file::File;
 //     FileInMemory(Vec<u8>)
 // }
 
-pub enum Entry {
+pub enum Entry<'a> {
     Files(Vec<PathBuf>),
-    InMemory(File),
+    InMemory(File<'a>),
 }
 
 pub trait Compressor {

src/compressors/tar.rs

@@ -5,8 +5,7 @@ use tar::Builder;
 use walkdir::WalkDir;
 
 use super::compressor::Entry;
-use crate::utils;
-use crate::{compressors::Compressor, file::File};
+use crate::{compressors::Compressor, file::File, utils};
 
 pub struct TarCompressor {}
 

src/decompressors/decompressor.rs

@@ -1,6 +1,6 @@
 use std::path::PathBuf;
 
-use crate::{cli::Flags, file::File};
+use crate::file::File;
 
 pub enum DecompressionResult {
     FilesUnpacked(Vec<PathBuf>),
@@ -12,6 +12,6 @@ pub trait Decompressor {
         &self,
         from: File,
         into: &Option<File>,
-        flags: Flags,
+        flags: &oof::Flags,
     ) -> crate::Result<DecompressionResult>;
 }

src/decompressors/tar.rs

@@ -8,13 +8,13 @@ use colored::Colorize;
 use tar::{self, Archive};
 
 use super::decompressor::{DecompressionResult, Decompressor};
-use crate::{cli::Flags, dialogs::Confirmation, file::File, utils};
+use crate::{dialogs::Confirmation, file::File, utils};
 
 #[derive(Debug)]
 pub struct TarDecompressor {}
 
 impl TarDecompressor {
-    fn unpack_files(from: File, into: &Path, flags: Flags) -> crate::Result<Vec<PathBuf>> {
+    fn unpack_files(from: File, into: &Path, flags: &oof::Flags) -> crate::Result<Vec<PathBuf>> {
         println!(
             "{}: attempting to decompress {:?}",
             "ouch".bright_blue(),
@@ -35,11 +35,11 @@ impl TarDecompressor {
             let mut file = file?;
 
             let file_path = PathBuf::from(into).join(file.path()?);
-            if file_path.exists() {
-                if !utils::permission_for_overwriting(&file_path, flags, &confirm)? {
-                    // The user does not want to overwrite the file
-                    continue;
-                }
+            if file_path.exists()
+                && !utils::permission_for_overwriting(&file_path, flags, &confirm)?
+            {
+                // The user does not want to overwrite the file
+                continue;
             }
 
             file.unpack_in(into)?;
@@ -64,7 +64,7 @@ impl Decompressor for TarDecompressor {
         &self,
         from: File,
         into: &Option<File>,
-        flags: Flags,
+        flags: &oof::Flags,
     ) -> crate::Result<DecompressionResult> {
         let destination_path = utils::get_destination_path(into);
 

src/decompressors/to_memory.rs

@@ -6,7 +6,7 @@ use std::{
 use colored::Colorize;
 
 use super::decompressor::{DecompressionResult, Decompressor};
-use crate::{cli::Flags, utils};
+use crate::utils;
 // use niffler;
 use crate::{extension::CompressionFormat, file::File};
 
@@ -28,8 +28,8 @@ fn get_decoder<'a>(
 }
 
 impl DecompressorToMemory {
-    fn unpack_file(from: &Path, format: CompressionFormat) -> crate::Result<Vec<u8>> {
-        let file = std::fs::read(from)?;
+    fn unpack_file(path: &Path, format: CompressionFormat) -> crate::Result<Vec<u8>> {
+        let file = std::fs::read(path)?;
 
         let mut reader = get_decoder(format, Box::new(&file[..]));
 
@@ -39,7 +39,7 @@ impl DecompressorToMemory {
         println!(
             "{}: {:?} extracted into memory ({} bytes).",
             "info".yellow(),
-            from,
+            path,
             bytes_read
         );
 
@@ -66,7 +66,7 @@ impl Decompressor for GzipDecompressor {
         &self,
         from: File,
         into: &Option<File>,
-        _: Flags,
+        _: &oof::Flags,
     ) -> crate::Result<DecompressionResult> {
         DecompressorToMemory::decompress(from, CompressionFormat::Gzip, into)
     }
@@ -77,7 +77,7 @@ impl Decompressor for BzipDecompressor {
         &self,
         from: File,
         into: &Option<File>,
-        _: Flags,
+        _: &oof::Flags,
     ) -> crate::Result<DecompressionResult> {
         DecompressorToMemory::decompress(from, CompressionFormat::Bzip, into)
     }
@@ -88,7 +88,7 @@ impl Decompressor for LzmaDecompressor {
         &self,
         from: File,
         into: &Option<File>,
-        _: Flags,
+        _: &oof::Flags,
     ) -> crate::Result<DecompressionResult> {
         DecompressorToMemory::decompress(from, CompressionFormat::Lzma, into)
     }

src/decompressors/zip.rs

@@ -8,10 +8,10 @@ use colored::Colorize;
 use zip::{self, read::ZipFile, ZipArchive};
 
 use super::decompressor::{DecompressionResult, Decompressor};
-use crate::{cli::Flags, dialogs::Confirmation, file::File, utils};
+use crate::{dialogs::Confirmation, file::File, utils};
 
 #[cfg(unix)]
-fn __unix_set_permissions(file_path: &PathBuf, file: &ZipFile) {
+fn __unix_set_permissions(file_path: &Path, file: &ZipFile) {
     use std::os::unix::fs::PermissionsExt;
 
     if let Some(mode) = file.unix_mode() {
@@ -34,13 +34,13 @@ impl ZipDecompressor {
         }
     }
 
-    pub fn zip_decompress<T>(
-        archive: &mut ZipArchive<T>,
+    pub fn zip_decompress<R>(
+        archive: &mut ZipArchive<R>,
         into: &Path,
-        flags: Flags,
+        flags: &oof::Flags,
     ) -> crate::Result<Vec<PathBuf>>
     where
-        T: Read + Seek,
+        R: Read + Seek,
     {
         let confirm = Confirmation::new("Do you want to overwrite 'FILE'?", Some("FILE"));
         let mut unpacked_files = vec![];
@@ -52,11 +52,11 @@ impl ZipDecompressor {
             };
 
             let file_path = into.join(file_path);
-            if file_path.exists() {
-                if !utils::permission_for_overwriting(&file_path, flags, &confirm)? {
-                    // The user does not want to overwrite the file
-                    continue;
-                }
+            if file_path.exists()
+                && !utils::permission_for_overwriting(&file_path, flags, &confirm)?
+            {
+                // The user does not want to overwrite the file
+                continue;
             }
 
             Self::check_for_comments(&file);
@@ -94,7 +94,7 @@ impl ZipDecompressor {
         Ok(unpacked_files)
     }
 
-    fn unpack_files(from: File, into: &Path, flags: Flags) -> crate::Result<Vec<PathBuf>> {
+    fn unpack_files(from: File, into: &Path, flags: &oof::Flags) -> crate::Result<Vec<PathBuf>> {
         println!("{} decompressing {:?}", "[OUCH]".bright_blue(), &from.path);
 
         match from.contents_in_memory {
@@ -119,7 +119,7 @@ impl Decompressor for ZipDecompressor {
         &self,
         from: File,
         into: &Option<File>,
-        flags: Flags,
+        flags: &oof::Flags,
     ) -> crate::Result<DecompressionResult> {
         let destination_path = utils::get_destination_path(into);
 

src/error.rs

@@ -15,10 +15,10 @@ pub enum Error {
     InvalidZipArchive(&'static str),
     PermissionDenied,
     UnsupportedZipArchive(&'static str),
-    InputsMustHaveBeenDecompressible(PathBuf),
+    // InputsMustBeDecompressible(PathBuf),
     InternalError,
     CompressingRootFolder,
-    WalkdirError
+    WalkdirError,
 }
 
 pub type Result<T> = std::result::Result<T, Error>;
@@ -44,11 +44,11 @@ impl fmt::Display for Error {
                 write!(f, "{} ", "[ERROR]".red())?;
                 write!(f, "cannot compress to \'{}\', likely because it has an unsupported (or missing) extension.", filename)
             }
-            Error::InputsMustHaveBeenDecompressible(file) => {
-                write!(f, "{} ", "[ERROR]".red())?;
-                write!(f, "file '{:?}' is not decompressible", file)
-            }
-            Error::WalkdirError => {                
+            // Error::InputsMustBeDecompressible(file) => {
+            //     write!(f, "{} ", "[ERROR]".red())?;
+            //     write!(f, "file '{:?}' is not decompressible", file)
+            // }
+            Error::WalkdirError => {
                 // Already printed in the From block
                 write!(f, "")
             }
@@ -61,8 +61,17 @@ impl fmt::Display for Error {
                 write!(f, "{} ", "[ERROR]".red())?;
                 let spacing = "        ";
                 writeln!(f, "It seems you're trying to compress the root folder.")?;
-                writeln!(f, "{}This is unadvisable since ouch does compressions in-memory.", spacing)?;
-                write!(f, "{}Use a more appropriate tool for this, such as {}.", spacing, "rsync".green())
+                writeln!(
+                    f,
+                    "{}This is unadvisable since ouch does compressions in-memory.",
+                    spacing
+                )?;
+                write!(
+                    f,
+                    "{}Use a more appropriate tool for this, such as {}.",
+                    spacing,
+                    "rsync".green()
+                )
             }
             Error::InternalError => {
                 write!(f, "{} ", "[ERROR]".red())?;
@@ -79,7 +88,7 @@ impl fmt::Display for Error {
 impl From<std::io::Error> for Error {
     fn from(err: std::io::Error) -> Self {
         match err.kind() {
-            std::io::ErrorKind::NotFound => Self::FileNotFound("".into()),
+            std::io::ErrorKind::NotFound => panic!("{}", err),
             std::io::ErrorKind::PermissionDenied => Self::PermissionDenied,
             std::io::ErrorKind::AlreadyExists => Self::AlreadyExists,
             _other => {
@@ -108,3 +117,9 @@ impl From<walkdir::Error> for Error {
         Self::WalkdirError
     }
 }
+
+impl From<oof::OofError> for Error {
+    fn from(_err: oof::OofError) -> Self {
+        todo!("We need to implement this properly");
+    }
+}

src/evaluator.rs

@@ -1,9 +1,13 @@
-use std::{ffi::OsStr, fs, io::Write, path::PathBuf};
+use std::{
+    fs,
+    io::Write,
+    path::{Path, PathBuf},
+};
 
 use colored::Colorize;
 
 use crate::{
-    cli::{Command, CommandKind, Flags},
+    cli::Command,
     compressors::{
         BzipCompressor, Compressor, Entry, GzipCompressor, LzmaCompressor, TarCompressor,
         ZipCompressor,
@@ -20,10 +24,13 @@ use crate::{
 
 pub struct Evaluator {}
 
+type BoxedCompressor = Box<dyn Compressor>;
+type BoxedDecompressor = Box<dyn Decompressor>;
+
 impl Evaluator {
     pub fn get_compressor(
         file: &File,
-    ) -> crate::Result<(Option<Box<dyn Compressor>>, Box<dyn Compressor>)> {
+    ) -> crate::Result<(Option<BoxedCompressor>, BoxedCompressor)> {
         let extension = match &file.extension {
             Some(extension) => extension.clone(),
             None => {
@@ -65,7 +72,7 @@ impl Evaluator {
 
     pub fn get_decompressor(
         file: &File,
-    ) -> crate::Result<(Option<Box<dyn Decompressor>>, Box<dyn Decompressor>)> {
+    ) -> crate::Result<(Option<BoxedDecompressor>, BoxedDecompressor)> {
         let extension = match &file.extension {
             Some(extension) => extension.clone(),
             None => {
@@ -100,24 +107,25 @@ impl Evaluator {
 
     fn decompress_file_in_memory(
         bytes: Vec<u8>,
-        file_path: PathBuf,
+        file_path: &Path,
         decompressor: Option<Box<dyn Decompressor>>,
-        output_file: &Option<File>,
+        output_file: Option<File>,
         extension: Option<Extension>,
-        flags: Flags,
+        flags: &oof::Flags,
     ) -> crate::Result<()> {
-        let output_file_path = utils::get_destination_path(output_file);
+        let output_file_path = utils::get_destination_path(&output_file);
 
-        let mut filename = file_path
+        let file_name = file_path
             .file_stem()
-            .unwrap_or_else(|| output_file_path.as_os_str());
+            .map(Path::new)
+            .unwrap_or(output_file_path);
 
-        if filename == "." {
+        if "." == file_name.as_os_str() {
             // I believe this is only possible when the supplied input has a name
             // of the sort `.tar` or `.zip' and no output has been supplied.
-            filename = OsStr::new("ouch-output");
+            // file_name = OsStr::new("ouch-output");
+            todo!("Pending review, what is this supposed to do??");
         }
-        let filename = PathBuf::from(filename);
 
         // If there is a decompressor to use, we'll create a file in-memory and decompress it
         let decompressor = match decompressor {
@@ -125,48 +133,52 @@ impl Evaluator {
             None => {
                 // There is no more processing to be done on the input file (or there is but currently unsupported)
                 // Therefore, we'll save what we have in memory into a file.
-                println!("{}: saving to {:?}.", "info".yellow(), filename);
+                println!("{}: saving to {:?}.", "info".yellow(), file_name);
 
-                if filename.exists() {
+                if file_name.exists() {
                     let confirm =
                         Confirmation::new("Do you want to overwrite 'FILE'?", Some("FILE"));
-                    if !utils::permission_for_overwriting(&filename, flags, &confirm)? {
+                    if !utils::permission_for_overwriting(&file_name, flags, &confirm)? {
                         return Ok(());
                     }
                 }
 
-                let mut f = fs::File::create(output_file_path.join(filename))?;
+                let mut f = fs::File::create(output_file_path.join(file_name))?;
                 f.write_all(&bytes)?;
                 return Ok(());
             }
         };
 
         let file = File {
-            path: filename,
+            path: file_name,
             contents_in_memory: Some(bytes),
             extension,
         };
 
-        let decompression_result = decompressor.decompress(file, output_file, flags)?;
+        let decompression_result = decompressor.decompress(file, &output_file, flags)?;
         if let DecompressionResult::FileInMemory(_) = decompression_result {
-            // Should not be reachable.
-            unreachable!();
+            unreachable!("Shouldn't");
         }
 
         Ok(())
     }
 
-    fn compress_files(files: Vec<PathBuf>, mut output: File, flags: Flags) -> crate::Result<()> {
+    fn compress_files(
+        files: Vec<PathBuf>,
+        output_path: &Path,
+        flags: &oof::Flags,
+    ) -> crate::Result<()> {
+        let mut output = File::from(output_path)?;
+
         let confirm = Confirmation::new("Do you want to overwrite 'FILE'?", Some("FILE"));
         let (first_compressor, second_compressor) = Self::get_compressor(&output)?;
 
         // TODO: use -y and -n here
-        let output_path = output.path.clone();
-        if output_path.exists() {
-            if !utils::permission_for_overwriting(&output_path, flags, &confirm)? {
-                // The user does not want to overwrite the file
-                return Ok(());
-            }
+        if output_path.exists()
+            && !utils::permission_for_overwriting(&output_path, flags, &confirm)?
+        {
+            // The user does not want to overwrite the file
+            return Ok(());
         }
 
         let bytes = match first_compressor {
@@ -187,7 +199,7 @@ impl Evaluator {
         println!(
             "{}: writing to {:?}. ({} bytes)",
             "info".yellow(),
-            &output_path,
+            output_path,
             bytes.len()
         );
         fs::write(output_path, bytes)?;
@@ -195,13 +207,21 @@ impl Evaluator {
         Ok(())
     }
 
-    fn decompress_file(file: File, output: &Option<File>, flags: Flags) -> crate::Result<()> {
+    fn decompress_file(
+        file_path: &Path,
+        output: Option<&Path>,
+        flags: &oof::Flags,
+    ) -> crate::Result<()> {
+        let file = File::from(file_path)?;
+        let output = match output {
+            Some(inner) => Some(File::from(inner)?),
+            None => None,
+        };
         let (first_decompressor, second_decompressor) = Self::get_decompressor(&file)?;
 
-        let file_path = file.path.clone();
         let extension = file.extension.clone();
 
-        let decompression_result = second_decompressor.decompress(file, output, flags)?;
+        let decompression_result = second_decompressor.decompress(file, &output, &flags)?;
 
         match decompression_result {
             DecompressionResult::FileInMemory(bytes) => {
@@ -230,20 +250,24 @@ impl Evaluator {
         Ok(())
     }
 
-    pub fn evaluate(command: Command, flags: Flags) -> crate::Result<()> {
-        let output = command.output.clone();
-
-        match command.kind {
-            CommandKind::Compression(files_to_compress) => {
-                // Safe to unwrap since output is mandatory for compression
-                let output = output.unwrap();
-                Self::compress_files(files_to_compress, output, flags)?;
-            }
-            CommandKind::Decompression(files_to_decompress) => {
-                for file in files_to_decompress {
-                    Self::decompress_file(file, &output, flags)?;
+    pub fn evaluate(command: Command, flags: &oof::Flags) -> crate::Result<()> {
+        match command {
+            Command::Compress {
+                files,
+                compressed_output_path,
+            } => Self::compress_files(files, &compressed_output_path, flags)?,
+            Command::Decompress {
+                files,
+                output_folder,
+            } => {
+                // From Option<PathBuf> to Option<&Path>
+                let output_folder = output_folder.as_ref().map(|path| Path::new(path));
+                for file in files.iter() {
+                    Self::decompress_file(file, output_folder, flags)?;
                 }
             }
+            Command::ShowHelp => todo!("call help function"),
+            Command::ShowVersion => todo!("call version function"),
         }
         Ok(())
     }

src/extension.rs

@@ -7,6 +7,8 @@ use std::{
 
 use CompressionFormat::*;
 
+use crate::utils::to_utf;
+
 /// Represents the extension of a file, but only really caring about
 /// compression formats (and .tar).
 /// Ex.: Extension::new("file.tar.gz") == Extension { first_ext: Some(Tar), second_ext: Gzip }
@@ -16,20 +18,17 @@ pub struct Extension {
     pub second_ext: CompressionFormat,
 }
 
-pub fn get_extension_from_filename(filename: &str) -> Option<(&str, &str)> {
-    let path = Path::new(filename);
+pub fn get_extension_from_filename(file_name: &OsStr) -> Option<(&OsStr, &OsStr)> {
+    let path = Path::new(file_name);
 
-    let ext = path.extension().and_then(OsStr::to_str)?;
+    let ext = path.extension()?;
 
-    let previous_extension = path
-        .file_stem()
-        .and_then(OsStr::to_str)
-        .and_then(get_extension_from_filename);
+    let previous_extension = path.file_stem().and_then(get_extension_from_filename);
 
     if let Some((_, prev)) = previous_extension {
         Some((prev, ext))
     } else {
-        Some(("", ext))
+        Some((OsStr::new(""), ext))
     }
 }
 
@@ -43,32 +42,32 @@ impl From<CompressionFormat> for Extension {
 }
 
 impl Extension {
-    pub fn new(filename: &str) -> crate::Result<Self> {
-        let ext_from_str = |ext| match ext {
-            "zip" => Ok(Zip),
-            "tar" => Ok(Tar),
-            "gz" => Ok(Gzip),
-            "bz" | "bz2" => Ok(Bzip),
-            "xz" | "lz" | "lzma" => Ok(Lzma),
-            other => Err(crate::Error::UnknownExtensionError(other.into())),
+    pub fn from(file_name: &OsStr) -> crate::Result<Self> {
+        let compression_format_from = |ext: &OsStr| match ext {
+            _ if ext == "zip" => Ok(Zip),
+            _ if ext == "tar" => Ok(Tar),
+            _ if ext == "gz" => Ok(Gzip),
+            _ if ext == "bz" || ext == "bz2" => Ok(Bzip),
+            _ if ext == "xz" || ext == "lz" || ext == "lzma" => Ok(Lzma),
+            other => Err(crate::Error::UnknownExtensionError(to_utf(other))),
         };
 
-        let (first_ext, second_ext) = match get_extension_from_filename(filename) {
+        let (first_ext, second_ext) = match get_extension_from_filename(&file_name) {
             Some(extension_tuple) => match extension_tuple {
-                ("", snd) => (None, snd),
+                (os_str, snd) if os_str.is_empty() => (None, snd),
                 (fst, snd) => (Some(fst), snd),
             },
-            None => return Err(crate::Error::MissingExtensionError(filename.into())),
+            None => return Err(crate::Error::MissingExtensionError(to_utf(file_name))),
         };
 
         let (first_ext, second_ext) = match (first_ext, second_ext) {
             (None, snd) => {
-                let ext = ext_from_str(snd)?;
+                let ext = compression_format_from(snd)?;
                 (None, ext)
             }
             (Some(fst), snd) => {
-                let snd = ext_from_str(snd)?;
-                let fst = ext_from_str(fst).ok();
+                let snd = compression_format_from(snd)?;
+                let fst = compression_format_from(fst).ok();
                 (fst, snd)
             }
         };
@@ -130,9 +129,9 @@ impl TryFrom<&PathBuf> for CompressionFormat {
 impl TryFrom<&str> for CompressionFormat {
     type Error = crate::Error;
 
-    fn try_from(filename: &str) -> Result<Self, Self::Error> {
-        let filename = Path::new(filename);
-        let ext = match filename.extension() {
+    fn try_from(file_name: &str) -> Result<Self, Self::Error> {
+        let file_name = Path::new(file_name);
+        let ext = match file_name.extension() {
             Some(ext) => ext,
             None => return Err(crate::Error::MissingExtensionError(String::new())),
         };

src/file.rs

@@ -1,11 +1,11 @@
-use std::path::PathBuf;
+use std::path::Path;
 
 use crate::extension::Extension;
 
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct File {
+pub struct File<'a> {
     /// File's (relative) path
-    pub path: PathBuf,
+    pub path: &'a Path,
     /// The bytes that compose the file.
     /// Only used when the whole file is kept in-memory
     pub contents_in_memory: Option<Vec<u8>>,
@@ -17,12 +17,15 @@ pub struct File {
     pub extension: Option<Extension>,
 }
 
-impl From<(PathBuf, Extension)> for File {
-    fn from((path, format): (PathBuf, Extension)) -> Self {
-        Self {
+impl<'a> File<'a> {
+    pub fn from(path: &'a Path) -> crate::Result<Self> {
+        let extension = Extension::from(path.as_ref())?;
+        eprintln!("dev warning: Should we really ignore the errors from the convertion above?");
+
+        Ok(File {
             path,
             contents_in_memory: None,
-            extension: Some(format),
-        }
+            extension: Some(extension),
+        })
     }
 }

src/main.rs

@@ -12,6 +12,8 @@ mod utils;
 use error::{Error, Result};
 use evaluator::Evaluator;
 
+use crate::cli::ParsedArgs;
+
 fn main() {
     if let Err(err) = run() {
         println!("{}", err);
@@ -20,7 +22,7 @@ fn main() {
 }
 
 fn run() -> crate::Result<()> {
-    let matches = cli::get_matches();
-    let (command, flags) = cli::parse_matches(matches)?;
-    Evaluator::evaluate(command, flags)
+    let ParsedArgs { command, flags } = cli::parse_args()?;
+    dbg!(&command);
+    Evaluator::evaluate(command, &flags)
 }

src/test.rs

@@ -1,211 +1,219 @@
 // TODO: remove tests of CompressionFormat::try_from since that's no longer used anywhere
 
-#[cfg(test)]
-mod cli {
-    use std::{convert::TryFrom, fs, path::Path};
+// use std::{
+//     convert::TryFrom,
+//     ffi::{OsStr, OsString},
+//     fs,
+//     path::Path,
+// };
 
-    use crate::{
-        cli::{clap_app, Command, CommandKind::*},
-        extension::{CompressionFormat::*, Extension},
-        file::File,
-    };
+// use crate::{
+//     cli::Command,
+//     extension::{CompressionFormat, CompressionFormat::*, Extension},
+//     file::File,
+// };
 
-    // ouch's command-line logic uses fs::canonicalize on its inputs so we cannot
-    // use made-up files for testing.
-    // make_dummy_file therefores creates a small temporary file to bypass fs::canonicalize errors
-    fn make_dummy_file<'a, P>(path: P) -> crate::Result<()>
-    where
-        P: AsRef<Path> + 'a,
-    {
-        fs::write(path.as_ref(), &[2, 3, 4, 5, 6, 7, 8, 9, 10])?;
-        Ok(())
-    }
+// // Helper
+// fn gen_args(text: &str) -> Vec<OsString> {
+//     let args = text.split_whitespace();
+//     args.map(OsString::from).collect()
+// }
 
-    #[test]
-    fn decompress_files_into_folder() -> crate::Result<()> {
-        make_dummy_file("file.zip")?;
-        let matches = clap_app().get_matches_from(vec!["ouch", "-i", "file.zip", "-o", "folder/"]);
-        let command_from_matches = Command::try_from(matches)?;
+// #[cfg(test)]
+// mod cli {
+//     use super::*;
 
-        assert_eq!(
-            command_from_matches,
-            Command {
-                kind: Decompression(vec![File {
-                    path: fs::canonicalize("file.zip")?,
-                    contents_in_memory: None,
-                    extension: Some(Extension::from(Zip))
-                }]),
-                output: Some(File {
-                    path: "folder".into(),
-                    contents_in_memory: None,
-                    extension: None
-                }),
-            }
-        );
+//     // ouch's command-line logic uses fs::canonicalize on its inputs so we cannot
+//     // use made-up files for testing.
+//     // make_dummy_file therefores creates a small temporary file to bypass fs::canonicalize errors
+//     fn make_dummy_file<'a, P>(path: P) -> crate::Result<()>
+//     where
+//         P: AsRef<Path> + 'a,
+//     {
+//         fs::write(path.as_ref(), &[2, 3, 4, 5, 6, 7, 8, 9, 10])?;
+//         Ok(())
+//     }
 
-        fs::remove_file("file.zip")?;
+//     #[test]
+//     fn decompress_files_into_folder() -> crate::Result<()> {
+//         make_dummy_file("file.zip")?;
+//         let args = gen_args("ouch -i file.zip -o folder/");
+//         let (command, flags) = cli::parse_args_and_flags_from(args)?;
 
-        Ok(())
-    }
+//         assert_eq!(
+//             command,
+//             Command::Decompress {
+//                 files: args,
+//                 compressed_output_path: PathBuf,
+//             } //     kind: Decompress(vec![File {
+//               //         path: fs::canonicalize("file.zip")?,
+//               //         contents_in_memory: None,
+//               //         extension: Some(Extension::from(Zip))
+//               //     }]),
+//               //     output: Some(File {
+//               //         path: "folder".into(),
+//               //         contents_in_memory: None,
+//               //         extension: None
+//               //     }),
+//               // }
+//         );
 
-    #[test]
-    fn decompress_files() -> crate::Result<()> {
-        make_dummy_file("my-cool-file.zip")?;
-        make_dummy_file("file.tar")?;
-        let matches =
-            clap_app().get_matches_from(vec!["ouch", "-i", "my-cool-file.zip", "file.tar"]);
-        let command_from_matches = Command::try_from(matches)?;
+//         fs::remove_file("file.zip")?;
 
-        assert_eq!(
-            command_from_matches,
-            Command {
-                kind: Decompression(vec![
-                    File {
-                        path: fs::canonicalize("my-cool-file.zip")?,
-                        contents_in_memory: None,
-                        extension: Some(Extension::from(Zip))
-                    },
-                    File {
-                        path: fs::canonicalize("file.tar")?,
-                        contents_in_memory: None,
-                        extension: Some(Extension::from(Tar))
-                    }
-                ],),
-                output: None,
-            }
-        );
+//         Ok(())
+//     }
 
-        fs::remove_file("my-cool-file.zip")?;
-        fs::remove_file("file.tar")?;
+//     #[test]
+//     fn decompress_files() -> crate::Result<()> {
+//         make_dummy_file("my-cool-file.zip")?;
+//         make_dummy_file("file.tar")?;
+//         let matches =
+//             clap_app().get_matches_from(vec!["ouch", "-i", "my-cool-file.zip", "file.tar"]);
+//         let command_from_matches = Command::try_from(matches)?;
 
-        Ok(())
-    }
+//         assert_eq!(
+//             command_from_matches,
+//             Command {
+//                 kind: Decompress(vec![
+//                     File {
+//                         path: fs::canonicalize("my-cool-file.zip")?,
+//                         contents_in_memory: None,
+//                         extension: Some(Extension::from(Zip))
+//                     },
+//                     File {
+//                         path: fs::canonicalize("file.tar")?,
+//                         contents_in_memory: None,
+//                         extension: Some(Extension::from(Tar))
+//                     }
+//                 ],),
+//                 output: None,
+//             }
+//         );
 
-    #[test]
-    fn compress_files() -> crate::Result<()> {
-        make_dummy_file("file")?;
-        make_dummy_file("file2.jpeg")?;
-        make_dummy_file("file3.ok")?;
+//         fs::remove_file("my-cool-file.zip")?;
+//         fs::remove_file("file.tar")?;
 
-        let matches = clap_app().get_matches_from(vec![
-            "ouch",
-            "-i",
-            "file",
-            "file2.jpeg",
-            "file3.ok",
-            "-o",
-            "file.tar",
-        ]);
-        let command_from_matches = Command::try_from(matches)?;
+//         Ok(())
+//     }
 
-        assert_eq!(
-            command_from_matches,
-            Command {
-                kind: Compression(vec![
-                    fs::canonicalize("file")?,
-                    fs::canonicalize("file2.jpeg")?,
-                    fs::canonicalize("file3.ok")?
-                ]),
-                output: Some(File {
-                    path: "file.tar".into(),
-                    contents_in_memory: None,
-                    extension: Some(Extension::from(Tar))
-                }),
-            }
-        );
+//     #[test]
+//     fn compress_files() -> crate::Result<()> {
+//         make_dummy_file("file")?;
+//         make_dummy_file("file2.jpeg")?;
+//         make_dummy_file("file3.ok")?;
 
-        fs::remove_file("file")?;
-        fs::remove_file("file2.jpeg")?;
-        fs::remove_file("file3.ok")?;
+//         let matches = clap_app().get_matches_from(vec![
+//             "ouch",
+//             "-i",
+//             "file",
+//             "file2.jpeg",
+//             "file3.ok",
+//             "-o",
+//             "file.tar",
+//         ]);
+//         let command_from_matches = Command::try_from(matches)?;
 
-        Ok(())
-    }
-}
+//         assert_eq!(
+//             command_from_matches,
+//             Command {
+//                 kind: Compress(vec![
+//                     fs::canonicalize("file")?,
+//                     fs::canonicalize("file2.jpeg")?,
+//                     fs::canonicalize("file3.ok")?
+//                 ]),
+//                 output: Some(File {
+//                     path: "file.tar".into(),
+//                     contents_in_memory: None,
+//                     extension: Some(Extension::from(Tar))
+//                 }),
+//             }
+//         );
 
-#[cfg(test)]
-mod cli_errors {
+//         fs::remove_file("file")?;
+//         fs::remove_file("file2.jpeg")?;
+//         fs::remove_file("file3.ok")?;
 
-    use std::convert::TryFrom;
+//         Ok(())
+//     }
+// }
 
-    use crate::cli::{clap_app, Command};
+// #[cfg(test)]
+// mod cli_errors {
 
-    #[test]
-    fn compress_files() -> crate::Result<()> {
-        let matches =
-            clap_app().get_matches_from(vec!["ouch", "-i", "a_file", "file2.jpeg", "file3.ok"]);
-        let res = Command::try_from(matches);
+//     #[test]
+//     fn compress_files() -> crate::Result<()> {
+//         let matches =
+//             clap_app().get_matches_from(vec!["ouch", "-i", "a_file", "file2.jpeg", "file3.ok"]);
+//         let res = Command::try_from(matches);
 
-        assert_eq!(
-            res,
-            Err(crate::Error::InputsMustHaveBeenDecompressible(
-                "a_file".into()
-            ))
-        );
+//         assert_eq!(
+//             res,
+//             Err(crate::Error::InputsMustHaveBeenDecompressible(
+//                 "a_file".into()
+//             ))
+//         );
 
-        Ok(())
-    }
-}
+//         Ok(())
+//     }
+// }
 
-#[cfg(test)]
-mod extension_extraction {
-    use std::convert::TryFrom;
+// #[cfg(test)]
+// mod extension_extraction {
 
-    use crate::extension::{CompressionFormat, Extension};
+//     #[test]
+//     fn test_extension_zip() {
+//         let path = "filename.tar.zip";
+//         assert_eq!(
+//             CompressionFormat::try_from(path),
+//             Ok(CompressionFormat::Zip)
+//         );
+//     }
 
-    #[test]
-    fn test_extension_zip() {
-        let path = "filename.tar.zip";
-        assert_eq!(
-            CompressionFormat::try_from(path),
-            Ok(CompressionFormat::Zip)
-        );
-    }
+//     #[test]
+//     fn test_extension_tar_gz() {
+//         let extension = Extension::from(OsStr::new("folder.tar.gz")).unwrap();
+//         assert_eq!(
+//             extension,
+//             Extension {
+//                 first_ext: Some(CompressionFormat::Tar),
+//                 second_ext: CompressionFormat::Gzip
+//             }
+//         );
+//     }
 
-    #[test]
-    fn test_extension_tar_gz() {
-        let extension = Extension::new("folder.tar.gz").unwrap();
-        assert_eq!(
-            extension,
-            Extension {
-                first_ext: Some(CompressionFormat::Tar),
-                second_ext: CompressionFormat::Gzip
-            }
-        );
-    }
+//     #[test]
+//     fn test_extension_tar() {
+//         let path = "pictures.tar";
+//         assert_eq!(
+//             CompressionFormat::try_from(path),
+//             Ok(CompressionFormat::Tar)
+//         );
+//     }
 
-    #[test]
-    fn test_extension_tar() {
-        let path = "pictures.tar";
-        assert_eq!(
-            CompressionFormat::try_from(path),
-            Ok(CompressionFormat::Tar)
-        );
-    }
+//     #[test]
+//     fn test_extension_gz() {
+//         let path = "passwords.tar.gz";
+//         assert_eq!(
+//             CompressionFormat::try_from(path),
+//             Ok(CompressionFormat::Gzip)
+//         );
+//     }
 
-    #[test]
-    fn test_extension_gz() {
-        let path = "passwords.tar.gz";
-        assert_eq!(
-            CompressionFormat::try_from(path),
-            Ok(CompressionFormat::Gzip)
-        );
-    }
+//     #[test]
+//     fn test_extension_lzma() {
+//         let path = "mygame.tar.lzma";
+//         assert_eq!(
+//             CompressionFormat::try_from(path),
+//             Ok(CompressionFormat::Lzma)
+//         );
+//     }
 
-    #[test]
-    fn test_extension_lzma() {
-        let path = "mygame.tar.lzma";
-        assert_eq!(
-            CompressionFormat::try_from(path),
-            Ok(CompressionFormat::Lzma)
-        );
-    }
-
-    #[test]
-    fn test_extension_bz() {
-        let path = "songs.tar.bz";
-        assert_eq!(
-            CompressionFormat::try_from(path),
-            Ok(CompressionFormat::Bzip)
-        );
-    }
-}
+//     #[test]
+//     fn test_extension_bz() {
+//         let path = "songs.tar.bz";
+//         assert_eq!(
+//             CompressionFormat::try_from(path),
+//             Ok(CompressionFormat::Bzip)
+//         );
+//     }
+// }

src/utils.rs

@@ -1,11 +1,13 @@
 use std::{
-    env, fs,
+    env,
+    ffi::OsStr,
+    fs,
     path::{Path, PathBuf},
 };
 
 use colored::Colorize;
 
-use crate::{cli::Flags, dialogs::Confirmation, extension::CompressionFormat, file::File};
+use crate::{dialogs::Confirmation, extension::CompressionFormat, file::File};
 
 pub(crate) fn ensure_exists<'a, P>(path: P) -> crate::Result<()>
 where
@@ -47,19 +49,18 @@ pub(crate) fn create_path_if_non_existent(path: &Path) -> crate::Result<()> {
     Ok(())
 }
 
-pub(crate) fn get_destination_path(dest: &Option<File>) -> &Path {
+pub(crate) fn get_destination_path<'a>(dest: &'a Option<File>) -> &'a Path {
     match dest {
-        Some(output) => {
+        Some(output_file) => {
             // Must be None according to the way command-line arg. parsing in Ouch works
-            assert_eq!(output.extension, None);
-
-            Path::new(&output.path)
+            assert_eq!(output_file.extension, None);
+            Path::new(&output_file.path)
         }
         None => Path::new("."),
     }
 }
 
-pub(crate) fn change_dir_and_return_parent(filename: &PathBuf) -> crate::Result<PathBuf> {
+pub(crate) fn change_dir_and_return_parent(filename: &Path) -> crate::Result<PathBuf> {
     let previous_location = env::current_dir()?;
 
     let parent = if let Some(parent) = filename.parent() {
@@ -68,21 +69,30 @@ pub(crate) fn change_dir_and_return_parent(filename: &PathBuf) -> crate::Result<
         return Err(crate::Error::CompressingRootFolder);
     };
 
-    env::set_current_dir(parent)?;
+    env::set_current_dir(parent).unwrap();
+
     Ok(previous_location)
 }
 
 pub fn permission_for_overwriting(
-    path: &PathBuf,
-    flags: Flags,
+    path: &Path,
+    flags: &oof::Flags,
     confirm: &Confirmation,
 ) -> crate::Result<bool> {
-    match flags {
-        Flags::AlwaysYes => return Ok(true),
-        Flags::AlwaysNo => return Ok(false),
-        Flags::None => {}
+    match (flags.is_present("yes"), flags.is_present("false")) {
+        (true, true) => {
+            unreachable!("This shoul've been cutted out in the ~/src/cli.rs filter flags function.")
+        }
+        (true, _) => return Ok(true),
+        (_, true) => return Ok(false),
+        _ => {}
     }
 
-    let file_path_str = &*path.as_path().to_string_lossy();
-    Ok(confirm.ask(Some(file_path_str))?)
+    let file_path_str = to_utf(path);
+    confirm.ask(Some(&file_path_str))
+}
+
+pub fn to_utf(os_str: impl AsRef<OsStr>) -> String {
+    let text = format!("{:?}", os_str.as_ref());
+    text.trim_matches('"').to_string()
 }