feat: preserve JSON indentation (#56)

Cargo.toml

@@ -20,6 +20,7 @@ readme = "./README.md"
 anyhow = "1.0.75"
 clap = { version = "4.4.3", features = ["derive"] }
 colored = "2.0.4"
+detect-indent = "0.1.0"
 indexmap = { version = "2.0.0", features = ["serde"] }
 inquire = "0.6.2"
 semver = "1.0.18"

src/json.rs

@@ -0,0 +1,28 @@
+use anyhow::Result;
+use detect_indent::{detect_indent, Indent};
+use serde::{Deserialize, Serialize};
+use serde_json::ser::PrettyFormatter;
+
+pub fn deserialize<'a, T>(value: &'a str) -> Result<(T, Indent)>
+where
+    T: Deserialize<'a>,
+{
+    let json = serde_json::from_str::<T>(value)?;
+    let indent = detect_indent(value);
+
+    Ok((json, indent))
+}
+
+pub fn serialize<T>(value: &T, indent: &Indent) -> Result<String>
+where
+    T: Serialize,
+{
+    let mut buf = Vec::new();
+    let formatter = PrettyFormatter::with_indent(indent.indent().as_bytes());
+    let mut serializer = serde_json::Serializer::with_formatter(&mut buf, formatter);
+
+    value.serialize(&mut serializer)?;
+    let json = String::from_utf8(buf)?;
+
+    Ok(json)
+}

src/main.rs

@@ -8,6 +8,7 @@ use std::time::Instant;
 
 mod args;
 mod collect;
+mod json;
 mod packages;
 mod plural;
 mod printer;

src/rules/empty_dependencies.rs

@@ -1,4 +1,5 @@
 use super::{Issue, IssueLevel, PackageType};
+use crate::json::{self};
 use anyhow::Result;
 use colored::Colorize;
 use std::{borrow::Cow, fmt::Display, fs, path::PathBuf};
@@ -71,15 +72,15 @@ impl Issue for EmptyDependenciesIssue {
         if let PackageType::Package(path) = package_type {
             let path = PathBuf::from(path).join("package.json");
             let value = fs::read_to_string(&path)?;
-            let mut value = serde_json::from_str::<serde_json::Value>(&value)?;
+            let (mut value, indent) = json::deserialize::<serde_json::Value>(&value)?;
             let dependency = self.dependency_kind.to_string();
 
             if let Some(dependency_field) = value.get(&dependency) {
                 if dependency_field.is_object() && dependency_field.as_object().unwrap().is_empty()
                 {
                     value.as_object_mut().unwrap().remove(&dependency);
 
-                    let value = serde_json::to_string_pretty(&value)?;
+                    let value = json::serialize(&value, &indent)?;
                     fs::write(path, value)?;
 
                     self.fixed = true;

src/rules/multiple_dependency_versions.rs

@@ -1,5 +1,5 @@
 use super::{Issue, IssueLevel, PackageType};
-use crate::packages::semversion::SemVersion;
+use crate::{json, packages::semversion::SemVersion};
 use anyhow::Result;
 use colored::Colorize;
 use indexmap::IndexMap;
@@ -144,7 +144,7 @@ impl Issue for MultipleDependencyVersionsIssue {
             for package in self.versions.keys() {
                 let path = PathBuf::from(package).join("package.json");
                 let value = fs::read_to_string(&path)?;
-                let mut value = serde_json::from_str::<serde_json::Value>(&value)?;
+                let (mut value, indent) = json::deserialize::<serde_json::Value>(&value)?;
 
                 if let Some(dependencies) = value.get_mut("dependencies") {
                     let dependencies = dependencies.as_object_mut().unwrap();
@@ -162,7 +162,7 @@ impl Issue for MultipleDependencyVersionsIssue {
                     }
                 }
 
-                let value = serde_json::to_string_pretty(&value)?;
+                let value = json::serialize(&value, &indent)?;
                 fs::write(path, value)?;
             }
 

src/rules/non_existant_packages.rs

@@ -1,4 +1,5 @@
 use super::{Issue, IssueLevel, PackageType};
+use crate::json;
 use anyhow::Result;
 use colored::Colorize;
 use std::{borrow::Cow, fs, path::PathBuf};
@@ -127,7 +128,7 @@ impl Issue for NonExistantPackagesIssue {
                 false => {
                     let path = PathBuf::from("package.json");
                     let value = fs::read_to_string(&path)?;
-                    let mut value = serde_json::from_str::<serde_json::Value>(&value)?;
+                    let (mut value, indent) = json::deserialize::<serde_json::Value>(&value)?;
 
                     value
                         .get_mut("workspaces")
@@ -140,7 +141,7 @@ impl Issue for NonExistantPackagesIssue {
                             !self.paths.contains(&package)
                         });
 
-                    let value = serde_json::to_string_pretty(&value)?;
+                    let value = json::serialize(&value, &indent)?;
                     fs::write(path, value)?;
 
                     self.fixed = true;

src/rules/root_package_private_field.rs

@@ -1,4 +1,5 @@
 use super::{Issue, IssueLevel, PackageType};
+use crate::json;
 use anyhow::Result;
 use colored::Colorize;
 use std::{borrow::Cow, fs, path::PathBuf};
@@ -48,14 +49,14 @@ impl Issue for RootPackagePrivateFieldIssue {
         if let PackageType::Root = package_type {
             let path = PathBuf::from("package.json");
             let value = fs::read_to_string(&path)?;
-            let mut value = serde_json::from_str::<serde_json::Value>(&value)?;
+            let (mut value, indent) = json::deserialize::<serde_json::Value>(&value)?;
 
             value
                 .as_object_mut()
                 .unwrap()
                 .insert("private".to_string(), serde_json::Value::Bool(true));
 
-            let value = serde_json::to_string_pretty(&value)?;
+            let value = json::serialize(&value, &indent)?;
             fs::write(path, value)?;
 
             self.fixed = true;

src/rules/types_in_dependencies.rs

@@ -1,4 +1,5 @@
 use super::{Issue, IssueLevel, PackageType};
+use crate::json;
 use anyhow::Result;
 use colored::Colorize;
 use indexmap::IndexMap;
@@ -84,7 +85,7 @@ impl Issue for TypesInDependenciesIssue {
         if let PackageType::Package(path) = package_type {
             let path = PathBuf::from(path).join("package.json");
             let value = fs::read_to_string(&path)?;
-            let mut value = serde_json::from_str::<serde_json::Value>(&value)?;
+            let (mut value, indent) = json::deserialize::<serde_json::Value>(&value)?;
 
             let dependencies = value
                 .get_mut("dependencies")
@@ -118,7 +119,7 @@ impl Issue for TypesInDependenciesIssue {
                 dev_dependencies.insert(package, version);
             }
 
-            let value = serde_json::to_string_pretty(&value)?;
+            let value = json::serialize(&value, &indent)?;
             fs::write(path, value)?;
 
             self.fixed = true;