Display modification times of input files in context diff

Fixes #31

Cargo.lock

@@ -11,6 +11,21 @@ dependencies = [
  "memchr",
 ]
 
+[[package]]
+name = "android-tzdata"
+version = "0.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e999941b234f3131b00bc13c22d06e8c5ff726d1b6318ac7eb276997bbb4fef0"
+
+[[package]]
+name = "android_system_properties"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "819e7219dbd41043ac279b19830f2efc897156490d7fd6ea916720117ee66311"
+dependencies = [
+ "libc",
+]
+
 [[package]]
 name = "anstyle"
 version = "1.0.6"
@@ -55,12 +70,44 @@ dependencies = [
  "serde",
 ]
 
+[[package]]
+name = "bumpalo"
+version = "3.15.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "7ff69b9dd49fd426c69a0db9fc04dd934cdb6645ff000864d98f7e2af8830eaa"
+
+[[package]]
+name = "cc"
+version = "1.0.90"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8cd6604a82acf3039f1144f54b8eb34e91ffba622051189e71b781822d5ee1f5"
+
 [[package]]
 name = "cfg-if"
 version = "1.0.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "baf1de4339761588bc0619e3cbc0120ee582ebb74b53b4efbf79117bd2da40fd"
 
+[[package]]
+name = "chrono"
+version = "0.4.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "8eaf5903dcbc0a39312feb77df2ff4c76387d591b9fc7b04a238dcf8bb62639a"
+dependencies = [
+ "android-tzdata",
+ "iana-time-zone",
+ "js-sys",
+ "num-traits",
+ "wasm-bindgen",
+ "windows-targets",
+]
+
+[[package]]
+name = "core-foundation-sys"
+version = "0.8.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "06ea2b9bc92be3c2baa9334a323ebca2d6f074ff852cd1d7b11064035cd3868f"
+
 [[package]]
 name = "diff"
 version = "0.1.13"
@@ -78,6 +125,7 @@ name = "diffutils"
 version = "0.3.0"
 dependencies = [
  "assert_cmd",
+ "chrono",
  "diff",
  "predicates",
  "pretty_assertions",
@@ -116,6 +164,38 @@ dependencies = [
  "num-traits",
 ]
 
+[[package]]
+name = "iana-time-zone"
+version = "0.1.60"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e7ffbb5a1b541ea2561f8c41c087286cc091e21e556a4f09a8f6cbf17b69b141"
+dependencies = [
+ "android_system_properties",
+ "core-foundation-sys",
+ "iana-time-zone-haiku",
+ "js-sys",
+ "wasm-bindgen",
+ "windows-core",
+]
+
+[[package]]
+name = "iana-time-zone-haiku"
+version = "0.1.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "f31827a206f56af32e590ba56d5d2d085f558508192593743f16b2306495269f"
+dependencies = [
+ "cc",
+]
+
+[[package]]
+name = "js-sys"
+version = "0.3.69"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "29c15563dc2726973df627357ce0c9ddddbea194836909d655df6a75d2cf296d"
+dependencies = [
+ "wasm-bindgen",
+]
+
 [[package]]
 name = "libc"
 version = "0.2.153"
@@ -128,6 +208,12 @@ version = "0.4.13"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "01cda141df6706de531b6c46c3a33ecca755538219bd484262fa09410c13539c"
 
+[[package]]
+name = "log"
+version = "0.4.21"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "90ed8c1e510134f979dbc4f070f87d4313098b704861a105fe34231c70a3901c"
+
 [[package]]
 name = "memchr"
 version = "2.7.1"
@@ -149,6 +235,12 @@ dependencies = [
  "autocfg",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
+
 [[package]]
 name = "predicates"
 version = "3.1.0"
@@ -322,6 +414,60 @@ dependencies = [
  "libc",
 ]
 
+[[package]]
+name = "wasm-bindgen"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4be2531df63900aeb2bca0daaaddec08491ee64ceecbee5076636a3b026795a8"
+dependencies = [
+ "cfg-if",
+ "wasm-bindgen-macro",
+]
+
+[[package]]
+name = "wasm-bindgen-backend"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "614d787b966d3989fa7bb98a654e369c762374fd3213d212cfc0251257e747da"
+dependencies = [
+ "bumpalo",
+ "log",
+ "once_cell",
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-macro"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a1f8823de937b71b9460c0c34e25f3da88250760bec0ebac694b49997550d726"
+dependencies = [
+ "quote",
+ "wasm-bindgen-macro-support",
+]
+
+[[package]]
+name = "wasm-bindgen-macro-support"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e94f17b526d0a461a191c78ea52bbce64071ed5c04c9ffe424dcb38f74171bb7"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+ "wasm-bindgen-backend",
+ "wasm-bindgen-shared",
+]
+
+[[package]]
+name = "wasm-bindgen-shared"
+version = "0.2.92"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "af190c94f2773fdb3729c55b007a722abb5384da03bc0986df4c289bf5567e96"
+
 [[package]]
 name = "winapi"
 version = "0.3.9"
@@ -353,6 +499,15 @@ version = "0.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "712e227841d057c1ee1cd2fb22fa7e5a5461ae8e48fa2ca79ec42cfc1931183f"
 
+[[package]]
+name = "windows-core"
+version = "0.52.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "33ab640c8d7e35bf8ba19b884ba838ceb4fba93a4e8c65a9059d08afcfc683d9"
+dependencies = [
+ "windows-targets",
+]
+
 [[package]]
 name = "windows-sys"
 version = "0.52.0"

Cargo.toml

@@ -15,6 +15,7 @@ name = "diffutils"
 path = "src/main.rs"
 
 [dependencies]
+chrono = "0.4.35"
 diff = "0.1.10"
 same-file = "1.0.6"
 

src/context_diff.rs

@@ -262,6 +262,22 @@ fn make_diff(
     results
 }
 
+fn get_modification_time(file_path: &str) -> String {
+    use chrono::{DateTime, Local};
+    use std::fs;
+
+    let metadata = fs::metadata(file_path).expect("Failed to get metadata");
+    let modification_time = metadata
+        .modified()
+        .expect("Failed to get modification time");
+    let modification_time: DateTime<Local> = modification_time.into();
+    let modification_time: String = modification_time
+        .format("%Y-%m-%d %H:%M:%S%.9f %z")
+        .to_string();
+
+    modification_time
+}
+
 #[must_use]
 pub fn diff(
     expected: &[u8],
@@ -271,7 +287,9 @@ pub fn diff(
     context_size: usize,
     stop_early: bool,
 ) -> Vec<u8> {
-    let mut output = format!("*** {expected_filename}\t\n--- {actual_filename}\t\n").into_bytes();
+    let expected_file_modified_time = get_modification_time(expected_filename);
+    let actual_file_modified_time = get_modification_time(actual_filename);
+    let mut output = format!("*** {expected_filename}\t{expected_file_modified_time}\n--- {actual_filename}\t{actual_file_modified_time}\n").into_bytes();
     let diff_results = make_diff(expected, actual, context_size, stop_early);
     if diff_results.is_empty() {
         return Vec::new();