First integration test

This test needs neatening but it is the first example of a working
integration test

src/display.rs

@@ -1,8 +1,7 @@
 extern crate ansi_term;
 
-use dust::Node;
-use std::cmp;
 use self::ansi_term::Colour::Fixed;
+use dust::Node;
 
 static UNITS: [char; 4] = ['T', 'G', 'M', 'K'];
 
@@ -77,18 +76,25 @@ fn display_node<S: Into<String>>(
     }
 }
 
-fn print_this_node(node_to_print: &Node, is_biggest: bool, indentation_str: &str) {
-    let padded_size = format!("{:>5}", human_readable_number(node_to_print.size()),);
+fn print_this_node(node: &Node, is_biggest: bool, indentation: &str) {
+    let pretty_size = format!("{:>5}", human_readable_number(node.size()),);
     println!(
+        "{}",
+        format_string(node.name(), is_biggest, pretty_size.as_ref(), indentation)
+    )
+}
+
+pub fn format_string(dir_name: &str, is_biggest: bool, size: &str, indentation: &str) -> String {
+    format!(
         "{} {} {}",
         if is_biggest {
-            Fixed(196).paint(padded_size)
+            Fixed(196).paint(size)
         } else {
-            Fixed(7).paint(padded_size)
+            Fixed(7).paint(size)
         },
-        indentation_str,
-        node_to_print.name()
-    );
+        indentation,
+        dir_name,
+    )
 }
 
 fn human_readable_number(size: u64) -> (String) {

src/main.rs

@@ -1,13 +1,14 @@
 #[macro_use]
 extern crate clap;
+extern crate assert_cli;
 extern crate dust;
 
+use self::display::draw_it;
 use clap::{App, AppSettings, Arg};
 use utils::{find_big_ones, get_dir_tree};
-use self::display::draw_it;
 
-mod utils;
 mod display;
+mod utils;
 
 static DEFAULT_NUMBER_OF_LINES: &'static str = "15";
 
@@ -42,3 +43,6 @@ fn main() {
     let slice_it = find_big_ones(&node_per_top_level_dir, number_of_lines);
     draw_it(permissions, &node_per_top_level_dir, &slice_it);
 }
+
+#[cfg(test)]
+mod tests;

src/test_dir/many/hello_file

@@ -0,0 +1 @@
+hello

src/tests.rs

@@ -0,0 +1,28 @@
+extern crate ansi_term;
+use super::*;
+use display::format_string;
+
+// TESTS TODO:
+// handle recursive dirs
+// handle soft links
+// handle hard links
+
+#[test]
+pub fn test_main() {
+    let r = format!(
+        "{}
+{}
+{}
+{}",
+        format_string("src/test_dir", true, " 4.0K", ""),
+        format_string("src/test_dir/many", true, " 4.0K", "└─┬",),
+        format_string("src/test_dir/many/hello_file", true, " 4.0K", "  ├──",),
+        format_string("src/test_dir/many/a_file", false, "   0B", "  └──",),
+    );
+
+    assert_cli::Assert::main_binary()
+        .with_args(&["src/test_dir"])
+        .stdout()
+        .is(r)
+        .unwrap();
+}