build: add bazel rules

Cargo.toml

@@ -3,7 +3,7 @@
 #   https://doc.rust-lang.org/cargo/reference/resolver.html#feature-resolver-version-2
 resolver = "2"
 
-members = ["crates/committer"]
+members = ["crates/committer", "crates/committer_cli"]
 
 [workspace.package]
 version = "0.1.0-rc.0"

crates/committer_cli/BUILD

@@ -0,0 +1,12 @@
+# To be used together with a bazel WORKSPACE file that contains the following definitions.
+load("@committer_crate//:defs.bzl", "all_crate_deps")
+load("@rules_rust//rust:defs.bzl", "rust_binary")
+
+rust_binary(
+    name="committer_exe",
+    srcs=glob(["src/**/*.rs"]),
+    visibility=["//visibility:public"],
+    deps=all_crate_deps(),
+    proc_macro_deps=all_crate_deps(proc_macro=True),
+    edition="2021",
+)

crates/committer_cli/Cargo.toml

@@ -0,0 +1,13 @@
+[package]
+name = "committer_cli"
+version.workspace = true
+edition.workspace = true
+repository.workspace = true
+license-file.workspace = true
+description = "Cli for the committer package."
+
+[lints]
+workspace = true
+
+[dev-dependencies]
+pretty_assertions.workspace = true

crates/committer_cli/src/main.rs

@@ -0,0 +1,20 @@
+use std::env;
+use std::path::Path;
+
+/// Main entry point of the committer CLI.
+fn main() {
+    // Open the input file.
+    let args: Vec<String> = env::args().collect();
+    let input_file_name = Path::new(&args[1]);
+    let output_file_name = Path::new(&args[2]);
+    assert!(
+        input_file_name.is_absolute() && output_file_name.is_absolute(),
+        "Given paths must be absolute"
+    );
+
+    // Business logic to be implemented here.
+    let output = std::fs::read(input_file_name).unwrap();
+
+    // Output to file.
+    std::fs::write(output_file_name, output).expect("Failed to write output");
+}