refactor: Split CLI in subcommands

bin/src/cli_args.rs

@@ -1,14 +1,44 @@
-use clap::Parser;
+use clap::{Parser, Subcommand};
 
 #[derive(Parser, Debug)]
 #[command(author, version, about, long_about = None)]
 pub struct CliArgs {
-    /// Runs only the diffing algorithm and outputs if the two files matches.
-    #[arg(short, long, num_args = 0)]
-    pub(crate) diff_only: bool,
+    #[command(subcommand)]
+    pub command: CliSubCommands,
 
+    /// The minimum log level to be displayed in output
+    #[arg(long, global=true, default_value_t = log::LevelFilter::Info)]
+    pub log_level: log::LevelFilter,
+}
+
+#[derive(Subcommand, Debug)]
+pub enum CliSubCommands {
+    #[command(about = "Runs only the diffing step on both input files")]
+    Diff(DiffCliArgs),
+    #[command(about = "Runs structured merge on the scenario provided")]
+    Merge(MergeCliArgs),
+}
+
+#[derive(Parser, Debug)]
+pub struct DiffCliArgs {
+    /// Path to file in left revision
+    #[arg(short, long)]
+    pub(crate) left_path: std::path::PathBuf,
+
+    /// Path to file in right revision
+    #[arg(short, long)]
+    pub(crate) right_path: std::path::PathBuf,
+
+    /// The language that the files being diffed are written in.
+    /// If not provided the language will try to be inferred by the extension.
+    #[arg(long)]
+    pub(crate) language: Option<String>,
+}
+
+#[derive(Parser, Debug)]
+pub struct MergeCliArgs {
     /// Path to file in base revision
-    #[arg(short, long, requires_if("false", "diff_only"))]
+    #[arg(short, long)]
     pub(crate) base_path: Option<std::path::PathBuf>,
 
     /// Path to file in left revision
@@ -20,16 +50,11 @@ pub struct CliArgs {
     pub(crate) right_path: std::path::PathBuf,
 
     /// Path where the merged file should be written
-    #[arg(short, long, requires_if("false", "diff_only"))]
+    #[arg(short, long)]
     pub(crate) merge_path: Option<std::path::PathBuf>,
 
-    /// The language that the files being merged are written in.
-    /// If not provided the language will try to be inferred by the extension of the base file.
+    /// The language that the files being diffed are written in.
+    /// If not provided the language will try to be inferred by the extension.
     #[arg(long)]
     pub(crate) language: Option<String>,
-
-    /// The log level provided for the execution.
-    /// If not provided defaults to INFO.
-    #[arg(long)]
-    pub(crate) log_level: Option<log::LevelFilter>,
 }

bin/src/main.rs

@@ -1,27 +1,25 @@
+use clap::Parser;
+use cli_args::{CliArgs, CliSubCommands, DiffCliArgs, MergeCliArgs};
+
 mod cli_args;
 mod cli_exit_codes;
 mod control;
 mod language;
 
-use clap::Parser;
-use cli_args::CliArgs;
-
 fn main() {
-    let args = cli_args::CliArgs::parse();
-    env_logger::builder()
-        .filter_level(args.log_level.unwrap_or(log::LevelFilter::Info))
-        .init();
+    let args = CliArgs::parse();
+    env_logger::builder().filter_level(args.log_level).init();
 
     log::info!("Starting Generic Merge tool execution");
     log::debug!("Parsed arguments: {:?}", args);
 
-    match !args.diff_only {
-        true => run_merge(args),
-        false => run_diff(args),
+    match args.command {
+        CliSubCommands::Diff(args) => run_diff(args),
+        CliSubCommands::Merge(args) => run_merge(args),
     }
 }
 
-fn run_merge(args: CliArgs) {
+fn run_merge(args: MergeCliArgs) {
     let base_path = args.base_path.unwrap();
 
     let base = std::fs::read_to_string(&base_path).unwrap_or_else(|error| {
@@ -69,7 +67,7 @@ fn run_merge(args: CliArgs) {
     }
 }
 
-fn run_diff(args: CliArgs) {
+fn run_diff(args: DiffCliArgs) {
     let left = std::fs::read_to_string(&args.left_path).unwrap_or_else(|error| {
         log::error!("Error while reading left file: {}", error);
         std::process::exit(cli_exit_codes::READING_FILE_ERROR)

bin/tests/cli.rs

@@ -5,7 +5,8 @@ use assert_cmd::prelude::*;
 #[test]
 fn if_there_is_a_conflict_it_returns_valid_exit_code() {
     let mut cmd = Command::cargo_bin("generic-merge").unwrap();
-    cmd.arg("--base-path=tests/scenarios/smoke_java/base.java")
+    cmd.arg("merge")
+        .arg("--base-path=tests/scenarios/smoke_java/base.java")
         .arg("--left-path=tests/scenarios/smoke_java/left.java")
         .arg("--right-path=tests/scenarios/smoke_java/right.java")
         .arg("--merge-path=tests/scenarios/smoke_java/merge.output.java")
@@ -17,7 +18,8 @@ fn if_there_is_a_conflict_it_returns_valid_exit_code() {
 #[test]
 fn if_there_is_no_conflict_it_returns_valid_exit_code() {
     let mut cmd = Command::cargo_bin("generic-merge").unwrap();
-    cmd.arg("--base-path=tests/scenarios/no_conflicts/base.java")
+    cmd.arg("merge")
+        .arg("--base-path=tests/scenarios/no_conflicts/base.java")
         .arg("--left-path=tests/scenarios/no_conflicts/left.java")
         .arg("--right-path=tests/scenarios/no_conflicts/right.java")
         .arg("--merge-path=tests/scenarios/no_conflicts/merge.output.java")
@@ -29,7 +31,7 @@ fn if_there_is_no_conflict_it_returns_valid_exit_code() {
 #[test]
 fn if_i_am_running_on_diff_mode_and_files_fully_match_it_returns_zero() {
     let mut cmd = Command::cargo_bin("generic-merge").unwrap();
-    cmd.arg("--diff-only")
+    cmd.arg("diff")
         .arg("--left-path=tests/diff_scenarios/java_files_full_match/left.java")
         .arg("--right-path=tests/diff_scenarios/java_files_full_match/right.java")
         .arg("--language=java")
@@ -40,7 +42,7 @@ fn if_i_am_running_on_diff_mode_and_files_fully_match_it_returns_zero() {
 #[test]
 fn if_i_am_running_on_diff_mode_and_files_do_not_fully_match_it_returns_one() {
     let mut cmd = Command::cargo_bin("generic-merge").unwrap();
-    cmd.arg("--diff-only")
+    cmd.arg("diff")
         .arg("--left-path=tests/diff_scenarios/java_files_not_fully_matching/left.java")
         .arg("--right-path=tests/diff_scenarios/java_files_not_fully_matching/right.java")
         .arg("--language=java")