Adding tests for list command

Signed-off-by: Dusan Malusev <dusan@dusanmalusev.dev>

hoster/Cargo.toml

@@ -1,11 +1,11 @@
 [package]
 name = "hoster"
-version = "0.1.1"
+version = "0.2.0"
 edition = "2021"
 authors = ["Dusan Malusev <dusan@dusanmalusev.dev>"]
 description = "Small parser and lexer library for Hosts file format"
 categories = ["parsing", "filesystem", "development-tools"]
-documentation = "https://docs.rs/hoster/0.1.1"
+documentation = "https://docs.rs/hoster/0.2.0"
 homepage = "https://github.com/BrosSquad/hosts"
 keywords = [
     "hosts",

hosts-edit/Cargo.toml

@@ -1,6 +1,6 @@
 [package]
 name = "hosts-edit"
-version = "0.1.1"
+version = "0.2.0"
 edition = "2021"
 authors = ["Dusan Malusev <dusan@dusanmalusev.dev>"]
 categories = ["parsing", "filesystem", "development-tools"]

hosts-edit/src/app.rs

@@ -63,8 +63,11 @@ where
             let _n = hosts.write(&data)?;
         }
         Commands::List { with_comments } => {
+            let stdout = std::io::stdout();
+
             list_command(
                 &mut file_options.append(false).read(true).open(path.into())?,
+                &mut  stdout.lock(),
                 with_comments,
             )?;
         }

hosts-edit/src/commands/list.rs

@@ -1,20 +1,26 @@
 use std::error::Error;
-use std::io::Read;
+use std::io::{Read, Write};
 
 use hoster::cst::CstNode;
 use hoster::parser::Parser;
 use hoster::tokenizer::Tokenizer;
 use hoster::visitor::CstVisitor;
 
-pub(crate) fn execute<R>(reader: &mut R, _with_comments: bool) -> Result<(), Box<dyn Error>>
+pub(crate) fn execute<R, W>(
+    reader: &mut R,
+    output: &mut W,
+    _with_comments: bool,
+) -> Result<(), Box<dyn Error>>
 where
     R: Read,
+    W: Write,
 {
     let tokens = Tokenizer::new_with_reader(reader).parse()?.get_tokens();
 
     let mut parser = Parser::builder()
         .visitor(Visitor {
             print_new_line: false,
+            output,
         })
         .build();
 
@@ -24,25 +30,30 @@ where
     Ok(())
 }
 
-pub(crate) struct Visitor {
+pub(crate) struct Visitor<W> {
     print_new_line: bool,
+    output: W,
 }
 
-impl CstVisitor for Visitor {
+impl<W> CstVisitor for Visitor<W>
+where
+    W: Write,
+{
     fn visit(&mut self, _idx: usize, node: &CstNode) -> Option<()> {
         match node {
             CstNode::Host(host) => {
                 self.print_new_line = true;
-                print!("\t{}", host);
+                write!(self.output, "\t{}", host).unwrap();
             }
             CstNode::IP(ip) => {
-                print!("{}", ip);
+                write!(self.output, "{}", ip).unwrap();
+
                 self.print_new_line = false;
             }
             CstNode::NewLine => {
                 if self.print_new_line {
                     self.print_new_line = false;
-                    println!();
+                    writeln!(self.output).unwrap();
                 }
             }
             _ => {}
@@ -51,3 +62,46 @@ impl CstVisitor for Visitor {
         Some(())
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use std::io::Cursor;
+
+    use super::*;
+
+    #[test]
+    fn test_list_without_comments() {
+        let mut output = Cursor::new(Vec::new());
+
+        let mut reader = Cursor::new(
+            "\
+# localhost name resolution is handled within DNS itself.
+# Added by Docker Desktop
+192.168.0.17\thost.docker.internal
+192.168.0.17 gateway.docker.internal
+# To allow the same kube context to work on the host and the container:
+\t127.0.0.1\tkubernetes.docker.internal
+
+
+# End of section
+"
+            .to_string(),
+        );
+
+        let result = execute(&mut reader, &mut output, false);
+
+        assert!(result.is_ok());
+
+        let output = String::from_utf8(output.into_inner()).unwrap();
+
+        assert_eq!(
+            "\
+192.168.0.17\thost.docker.internal
+192.168.0.17\tgateway.docker.internal
+127.0.0.1\tkubernetes.docker.internal
+"
+            .to_string(),
+            output
+        )
+    }
+}