Merge pull request #16 from ilkecan/json-output

report: add alternative output in JSON

Cargo.lock

@@ -72,6 +72,8 @@ dependencies = [
  "clap",
  "rnix",
  "rowan",
+ "serde",
+ "serde_json",
  "walkdir",
 ]
 
@@ -106,6 +108,12 @@ dependencies = [
  "hashbrown 0.11.2",
 ]
 
+[[package]]
+name = "itoa"
+version = "1.0.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "1aab8fc367588b89dcee83ab0fd66b72b50b72fa1904d7095045ace2b0c81c35"
+
 [[package]]
 name = "libc"
 version = "0.2.117"
@@ -175,6 +183,12 @@ version = "1.1.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "08d43f7aa6b08d49f382cde6a7982047c3426db949b1424bc4b7ec9ae12c6ce2"
 
+[[package]]
+name = "ryu"
+version = "1.0.9"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "73b4b750c782965c211b42f022f59af1fbceabdd026623714f104152f1ec149f"
+
 [[package]]
 name = "same-file"
 version = "1.0.6"
@@ -190,6 +204,17 @@ version = "1.0.136"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ce31e24b01e1e524df96f1c2fdd054405f8d7376249a5110886fb4b658484789"
 
+[[package]]
+name = "serde_json"
+version = "1.0.78"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "d23c1ba4cf0efd44be32017709280b32d1cea5c3f1275c3b6d9e8bc54f758085"
+dependencies = [
+ "itoa",
+ "ryu",
+ "serde",
+]
+
 [[package]]
 name = "smol_str"
 version = "0.1.21"

Cargo.toml

@@ -15,3 +15,9 @@ rnix = "0.10"
 clap = "3"
 walkdir = "2"
 ariadne = "0.1"
+serde = { version = "1.0.136", optional = true }
+serde_json = { version = "1.0.78", optional = true }
+
+[features]
+default = []
+json-out = [ "serde", "serde_json" ]

src/main.rs

@@ -56,6 +56,16 @@ fn main() {
                 .long("fail")
                 .help("Exit with 1 if unused code has been found"),
         )
+        .arg(
+            clap::Arg::new("OUTPUT_FORMAT")
+                .short('o')
+                .long("output-format")
+                .takes_value(true)
+                .possible_value("human-readable")
+                .possible_value("json")
+                .default_value("human-readable")
+                .help("Output format to use"),
+        )
         .arg(
             clap::Arg::new("FILE_PATHS")
                 .multiple_values(true)
@@ -80,6 +90,7 @@ fn main() {
             .to_str()
             .map_or(false, |s| s == "." || ! s.starts_with('.'))
     };
+    let output_format = matches.value_of("OUTPUT_FORMAT");
 
     let file_paths = matches.values_of("FILE_PATHS").expect("FILE_PATHS");
     let files = file_paths.flat_map(|path| {
@@ -125,7 +136,14 @@ fn main() {
         let results = settings.find_dead_code(&ast.node());
         report_count += results.len();
         if !quiet && !results.is_empty() {
-            crate::report::print(file.to_string(), &content, &results);
+            match output_format {
+                Some("human-readable") => crate::report::print(file.to_string(), &content, &results),
+                #[cfg(feature = "json-out")]
+                Some("json") => crate::report::print_json(&file.to_string(), &content, &results),
+                #[cfg(not(feature = "json-out"))]
+                Some("json") => println!("`deadnix` needs to be built with `json-out` feature flag for JSON output format."),
+                _ => println!("Unknown output format."), // clap shouldn't allow this case
+            };
         }
         if edit {
             let new_ast = crate::edit::edit_dead_code(&content, results.into_iter());

src/report.rs

@@ -2,6 +2,9 @@ use ariadne::{Config, Label, Report, ReportKind, sources};
 use crate::dead_code::DeadCode;
 use rnix::{TextSize, types::TypedNode};
 
+#[cfg(feature = "json-out")]
+use serde_json::json;
+
 // assumes results to be sorted by occurrence in file
 pub fn print(file: String, content: &str, results: &[DeadCode]) {
     let first_result_range = results[0].binding.name.node().text_range();
@@ -55,3 +58,37 @@ pub fn print(file: String, content: &str, results: &[DeadCode]) {
         ]))
         .unwrap();
 }
+
+#[cfg(feature = "json-out")]
+pub fn print_json(file: &str, content: &str, results: &[DeadCode]) {
+    let mut offset = 0;
+    let mut offsets = vec![offset];
+    while let Some(next) = content[offset..].find('\n') {
+        offset += next + 1;
+        offsets.push(offset);
+    }
+
+    let json = json!({
+        "file": file,
+        "results": results.iter().map(|result| {
+            let range = result.binding.name.node().text_range();
+            let start = usize::from(range.start());
+            let mut line_number = 0;
+            let mut line_offset = 0;
+            for &offset in &offsets {
+                if start < offset {
+                    break;
+                }
+                line_number += 1;
+                line_offset = offset;
+            }
+            json!({
+                "message": format!("{}", result),
+                "line": line_number,
+                "column": start - line_offset + 1,
+                "endColumn": usize::from(range.end()) - line_offset + 1,
+            })
+        }).collect::<serde_json::Value>(),
+    });
+    println!("{}", json);
+}