jsondoclint: Parse args with clap.

Cargo.lock

@@ -597,7 +597,7 @@ checksum = "23b71c3ce99b7611011217b366d923f1d0a7e07a92bb2dbf1e84508c673ca3bd"
 dependencies = [
  "atty",
  "bitflags",
- "clap_derive",
+ "clap_derive 3.2.18",
  "clap_lex 0.2.2",
  "indexmap",
  "once_cell",
@@ -614,7 +614,9 @@ checksum = "6bf8832993da70a4c6d13c581f4463c2bdda27b9bf1c5498dc4365543abe6d6f"
 dependencies = [
  "atty",
  "bitflags",
+ "clap_derive 4.0.13",
  "clap_lex 0.3.0",
+ "once_cell",
  "strsim",
  "termcolor",
 ]
@@ -641,6 +643,19 @@ dependencies = [
  "syn",
 ]
 
+[[package]]
+name = "clap_derive"
+version = "4.0.13"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "c42f169caba89a7d512b5418b09864543eeb4d497416c917d7137863bd2076ad"
+dependencies = [
+ "heck",
+ "proc-macro-error",
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "clap_lex"
 version = "0.2.2"
@@ -2097,6 +2112,7 @@ name = "jsondoclint"
 version = "0.1.0"
 dependencies = [
  "anyhow",
+ "clap 4.0.15",
  "fs-err",
  "rustdoc-json-types",
  "serde_json",

src/tools/jsondoclint/Cargo.toml

@@ -7,6 +7,7 @@ edition = "2021"
 
 [dependencies]
 anyhow = "1.0.62"
+clap = { version = "4.0.15", features = ["derive"] }
 fs-err = "2.8.1"
 rustdoc-json-types = { version = "0.1.0", path = "../../rustdoc-json-types" }
 serde_json = "1.0.85"

src/tools/jsondoclint/src/main.rs

@@ -1,6 +1,5 @@
-use std::env;
-
-use anyhow::{anyhow, bail, Result};
+use anyhow::{bail, Result};
+use clap::Parser;
 use fs_err as fs;
 use rustdoc_json_types::{Crate, Id, FORMAT_VERSION};
 use serde_json::Value;
@@ -21,8 +20,15 @@ enum ErrorKind {
     Custom(String),
 }
 
+#[derive(Parser)]
+struct Cli {
+    /// The path to the json file to be linted
+    path: String,
+}
+
 fn main() -> Result<()> {
-    let path = env::args().nth(1).ok_or_else(|| anyhow!("no path given"))?;
+    let Cli { path } = Cli::parse();
+
     let contents = fs::read_to_string(&path)?;
     let krate: Crate = serde_json::from_str(&contents)?;
     assert_eq!(krate.format_version, FORMAT_VERSION);