Merge pull request #10 from srithon/topic-7-cli-write-file

Fix documented CLI behavior

CHANGELOG.md

@@ -1,3 +1,9 @@
+# 0.3.1
+
+- Program now sets the exit code properly instead of printing it out
+- Rather than printing the compiled document to stdout, correctly writes it to files
+- Program now prints long help when no arguments are passed in
+
 # 0.3.0
 
 - Added support for string/number constant interpolation

Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "kmonadx"
-version = "0.3.0"
+version = "0.3.1"
 edition = "2018"
 
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html

src/main.rs

@@ -9,9 +9,18 @@ use kmonadx::kbdx::diagnostic::DiagnosticAggregator;
 
 use std::cell::UnsafeCell;
 
-fn main() -> Result<()> {
+// Because std::process::exit terminates the program without running destructors, we need a helper
+// function to wrap all the functionality so that there is nothing left to cleanup in the actual
+// main function.
+// This function returns the exit code.
+fn _main() -> Result<usize> {
     let cli = CLI::from_args();
 
+    if cli.filenames.is_empty() {
+        CLI::clap().print_long_help()?;
+        return Ok(1);
+    }
+
     // https://github.com/yaahc/color-eyre/issues/83
     // We do not want the "Backtrace has been omitted" message to display
     color_eyre::config::HookBuilder::default()
@@ -26,7 +35,7 @@ fn main() -> Result<()> {
     // errors
     let files_content = UnsafeCell::new(Vec::with_capacity(cli.filenames.len()));
 
-    for file_name in cli.filenames {
+    for mut file_name in cli.filenames {
         let file_contents = std::fs::read_to_string(&file_name)
             .wrap_err(format!("Unable to read file: {:?}", file_name))
             .suggestion("Please specify a file that exists")?;
@@ -37,14 +46,25 @@ fn main() -> Result<()> {
             files_content_ref.last().unwrap()
         };
 
-        let file_handle = diagnostics.new_file(
+        let mut file_handle = diagnostics.new_file(
             file_name
                 .to_str()
                 .ok_or_else(|| eyre!("Filename is not valid unicode!"))?
                 .to_owned(),
             file_contents,
         );
 
+        // OPTIMIZE: shouldn't have to read the file before handling this case
+        if let Some(ext) = file_name.extension() {
+            if ext == "kbd" {
+                file_handle.error(format!(
+                    "Cannot compile '{:?}'; file already has .kbd extension!",
+                    file_name
+                ));
+                continue;
+            }
+        }
+
         let mut parser = Parser::new(file_contents, file_handle);
 
         if cli.debug_output {
@@ -55,10 +75,13 @@ fn main() -> Result<()> {
                     match compiler.compile_string() {
                         Ok(string) => {
                             if !cli.check {
-                                println!("{}", string);
+                                // replace kbdx extension with kbd or append .kbd if there is no
+                                // extension
+                                file_name.set_extension("kbd");
+                                std::fs::write(file_name, string)?;
                             }
-                        },
-                        Err(_) => break
+                        }
+                        Err(_) => break,
                     }
                 }
                 Err(_) => break,
@@ -75,7 +98,10 @@ fn main() -> Result<()> {
     // are no more destructors left to run.
     // END QUOTE
     let exit_code: usize = diagnostics.emit_all()?.into();
-    eprintln!("Exit code would be {}", exit_code);
+    Ok(exit_code)
+}
 
-    Ok(())
+fn main() -> Result<()> {
+    let exit_code = _main()?;
+    std::process::exit(exit_code as i32)
 }