Add atomicwrites

Cargo.lock

@@ -63,6 +63,17 @@ version = "0.7.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "7c02d123df017efcdfbd739ef81735b36c5ba83ec3c59c80a9d7ecc718f92e50"
 
+[[package]]
+name = "atomicwrites"
+version = "0.4.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "fc7b2dbe9169059af0f821e811180fddc971fc210c776c133c7819ccd6e478db"
+dependencies = [
+ "rustix",
+ "tempfile",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "bitflags"
 version = "1.3.2"
@@ -142,6 +153,22 @@ version = "0.8.20"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "22ec99545bb0ed0ea7bb9b8e1e9122ea386ff8a48c0922e43f36d45ab09e0e80"
 
+[[package]]
+name = "errno"
+version = "0.3.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "534c5cf6194dfab3db3242765c03bbe257cf92f22b38f6bc0c58d59108a820ba"
+dependencies = [
+ "libc",
+ "windows-sys 0.52.0",
+]
+
+[[package]]
+name = "fastrand"
+version = "2.1.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "e8c02a5121d4ea3eb16a80748c74f5549a5665e4c21333c6098f283870fbdea6"
+
 [[package]]
 name = "filetime"
 version = "0.2.25"
@@ -209,6 +236,7 @@ name = "jsoncutil"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "atomicwrites",
  "clap",
  "fjson",
  "notify-debouncer-mini",
@@ -251,6 +279,12 @@ dependencies = [
  "redox_syscall",
 ]
 
+[[package]]
+name = "linux-raw-sys"
+version = "0.4.14"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "78b3ae25bc7c8c38cec158d1f2757ee79e9b3740fbc7ccf0e59e4b08d793fa89"
+
 [[package]]
 name = "log"
 version = "0.4.22"
@@ -299,6 +333,12 @@ dependencies = [
  "notify",
 ]
 
+[[package]]
+name = "once_cell"
+version = "1.19.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3fdb12b2476b595f9358c5161aa467c2438859caa136dec86c26fdd2efe17b92"
+
 [[package]]
 name = "proc-macro2"
 version = "1.0.86"
@@ -326,6 +366,19 @@ dependencies = [
  "bitflags 2.6.0",
 ]
 
+[[package]]
+name = "rustix"
+version = "0.38.35"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "a85d50532239da68e9addb745ba38ff4612a242c1c7ceea689c4bc7c2f43c36f"
+dependencies = [
+ "bitflags 2.6.0",
+ "errno",
+ "libc",
+ "linux-raw-sys",
+ "windows-sys 0.52.0",
+]
+
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -352,6 +405,19 @@ dependencies = [
  "unicode-ident",
 ]
 
+[[package]]
+name = "tempfile"
+version = "3.12.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "04cbcdd0c794ebb0d4cf35e88edd2f7d2c4c3e9a5a6dab322839b321c6a87a64"
+dependencies = [
+ "cfg-if",
+ "fastrand",
+ "once_cell",
+ "rustix",
+ "windows-sys 0.59.0",
+]
+
 [[package]]
 name = "unicode-ident"
 version = "1.0.12"

Cargo.toml

@@ -5,6 +5,7 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.86"
+atomicwrites = "0.4.3"
 clap = { version = "4.5.16", features = ["derive"] }
 fjson = "0.3.1"
 notify-debouncer-mini = "0.4.1"

src/main.rs

@@ -1,4 +1,5 @@
 use anyhow::{bail, Context, Result};
+use atomicwrites::{AtomicFile, OverwriteBehavior::DisallowOverwrite};
 use clap::{Args, Parser, Subcommand};
 use notify_debouncer_mini::{new_debouncer, notify::*, DebounceEventResult};
 use std::{
@@ -69,46 +70,34 @@ fn format_single_file(args: &FmtArgs) -> Result<()> {
         return Ok(());
     }
 
-    if let Some(ref output) = args.output {
+    if let Some(ref output_file) = args.output {
-        let mut output_file = fs::OpenOptions::new()
-            .create(true)
-            .truncate(true)
-            .write(true)
-            .open(output)
-            .context("Opening output file")?;
-
         let output = fjson::to_jsonc(&input_str).context("Formatting to jsonc")?;
 
-        output_file
+        AtomicFile::new(output_file, DisallowOverwrite)
-            .write_all(&output.as_bytes())
+            .write(|f| f.write_all(&output.as_bytes()))
             .context("Writing jsonc output")?;
-
-        output_file.flush().context("Flushing jsonc output")?;
     }
 
-    if let Some(ref json_output) = args.json_output {
+    if let Some(ref json_output_file) = args.json_output {
-        let mut json_output_file = fs::OpenOptions::new()
-            .create(true)
-            .truncate(true)
-            .write(true)
-            .open(json_output)
-            .context("Opening output file")?;
-
         let output = if args.compact {
             fjson::to_json(&input_str).context("Formatting to json")
         } else {
             fjson::to_json_compact(&input_str).context("Formatting to json")
         }?;
 
-        json_output_file
+        AtomicFile::new(json_output_file, DisallowOverwrite)
-            .write_all(&output.as_bytes())
+            .write(|f| f.write_all(&output.as_bytes()))
-            .context("Writing json output")?;
+            .context("Writing jsonc output")?;
-        json_output_file.flush().context("Flushing json output")?;
     }
 
     Ok(())
 }
 
+// let af = AtomicFile::new("foo", DisallowOverwrite);
+// af.write(|f| {
+//     f.write_all(b"HELLO")
+// })?;
+
 // fn x() {
 //     // Select recommended watcher for debouncer.
 //     // Using a callback here, could also be a channel.