Eliminate std::process::exit

src/main.rs

@@ -4,44 +4,65 @@ use std::{
     ffi::OsString,
     fs::File,
     io::{self, Write},
+    process::ExitCode,
 };
 
 use pgxn_meta::Validator;
 use serde_json::Value;
 
-fn main() -> Result<(), Box<dyn Error>> {
+fn main() -> Result<ExitCode, Box<dyn Error>> {
     run(io::stdout(), env::args_os().collect::<Vec<_>>())
 }
 
-fn run<I>(mut out: impl Write, args: I) -> Result<(), Box<dyn Error>>
+fn run<I>(mut out: impl Write, args: I) -> Result<ExitCode, Box<dyn Error>>
 where
     I: IntoIterator,
     I::Item: Into<OsString>,
 {
-    let file = parse_args(&mut out, args)?;
-    validate(&file)
+    let res = parse_args(&mut out, args)?;
+    if !res.exit {
+        validate(&res.file)?;
+    }
+    Ok(ExitCode::SUCCESS)
+}
+
+struct Args {
+    exit: bool,
+    file: String,
 }
 
-fn parse_args<I>(out: &mut impl Write, args: I) -> Result<String, Box<dyn Error>>
+fn parse_args<I>(out: &mut impl Write, args: I) -> Result<Args, Box<dyn Error>>
 where
     I: IntoIterator,
     I::Item: Into<OsString>,
 {
     use lexopt::prelude::*;
-    let mut file = String::from("META.json");
+    let mut res = Args {
+        exit: false,
+        file: String::from("META.json"),
+    };
     let mut parser = lexopt::Parser::from_iter(args);
 
     while let Some(arg) = parser.next()? {
         match arg {
-            Short('h') | Long("help") => usage(out, &parser)?,
-            Short('v') | Long("version") => version(out, &parser)?,
-            Short('m') | Long("man") => docs(out)?,
-            Value(val) => file = val.string()?,
+            Short('h') | Long("help") => {
+                usage(out, &parser)?;
+                res.exit = true
+            }
+            Short('v') | Long("version") => {
+                version(out, &parser)?;
+                res.exit = true
+            }
+            Short('m') | Long("man") => {
+                docs(out)?;
+                res.exit = true
+            }
+            Value(val) => res.file = val.string()?,
             _ => return Err(Box::new(arg.unexpected())),
         }
     }
 
-    Ok(file)
+    Ok(res)
 }
 
 fn validate(file: &str) -> Result<(), Box<dyn Error>> {
@@ -68,16 +89,15 @@ fn usage(out: &mut impl Write, p: &lexopt::Parser) -> Result<(), Box<dyn Error>>
         \x20 -v --version  Print the version number and exit",
         bn!(p),
     )?;
-
-    std::process::exit(0);
+    Ok(())
 }
 
 fn version(out: &mut impl Write, p: &lexopt::Parser) -> Result<(), Box<dyn Error>> {
     writeln!(out, "{} {}", bn!(p), env!("CARGO_PKG_VERSION"))?;
-    std::process::exit(0);
+    Ok(())
 }
 
 fn docs(out: &mut impl Write) -> Result<(), Box<dyn Error>> {
     writeln!(out, "Docs")?;
-    std::process::exit(0);
+    Ok(())
 }