Align doc-comments in --list output (#273)

src/run.rs

@@ -1,9 +1,10 @@
 use common::*;
 
-use std::{convert, ffi};
+use std::{convert, ffi, cmp};
 use clap::{App, Arg, ArgGroup, AppSettings};
 use misc::maybe_s;
 use configuration::DEFAULT_SHELL;
+use unicode_width::UnicodeWidthStr;
 
 macro_rules! die {
   ($($arg:tt)*) => {{
@@ -260,6 +261,26 @@ pub fn run() {
   }
 
   if matches.is_present("LIST") {
+    let mut line_widths: Map<&str, usize> = Map::new();
+
+    for (name, recipe) in &justfile.recipes {
+      if recipe.private {
+        continue;
+      }
+
+      let mut line_width = UnicodeWidthStr::width(*name);
+
+      for parameter in &recipe.parameters {
+        line_width += UnicodeWidthStr::width(format!(" {}", parameter).as_str());
+      }
+
+      if line_width <= 30 {
+        line_widths.insert(name, line_width);
+      }
+    }
+
+    let max_line_width = cmp::min(line_widths.values().cloned().max().unwrap_or(0), 30);
+
     let doc_color = color.stdout().doc();
     println!("Available recipes:");
     for (name, recipe) in &justfile.recipes {
@@ -275,7 +296,10 @@ pub fn run() {
         }
       }
       if let Some(doc) = recipe.doc {
-        print!(" {} {}", doc_color.paint("#"), doc_color.paint(doc));
+        print!(
+          " {:padding$}{} {}", "", doc_color.paint("#"), doc_color.paint(doc),
+          padding = max_line_width.saturating_sub(line_widths.get(name).cloned().unwrap_or(max_line_width))
+        );
       }
       println!();
     }

tests/integration.rs

@@ -1039,6 +1039,57 @@ _private-recipe:
   status:   EXIT_SUCCESS,
 }
 
+integration_test! {
+  name:     list_alignment,
+  justfile: r#"
+
+# this does a thing
+hello a b='B	' c='C':
+  echo {{a}} {{b}} {{c}}
+
+# something else
+a Z="\t z":
+
+# this recipe will not appear
+_private-recipe:
+"#,
+  args:     ("--list"),
+  stdout:   r"Available recipes:
+    a Z='\t z'            # something else
+    hello a b='B\t' c='C' # this does a thing
+",
+  stderr:   "",
+  status:   EXIT_SUCCESS,
+}
+
+integration_test! {
+  name:     list_alignment_long,
+  justfile: r#"
+
+# this does a thing
+hello a b='B	' c='C':
+  echo {{a}} {{b}} {{c}}
+
+# this does another thing
+x a b='B	' c='C':
+  echo {{a}} {{b}} {{c}}
+
+# something else
+this-recipe-is-very-very-very-important Z="\t z":
+
+# this recipe will not appear
+_private-recipe:
+"#,
+  args:     ("--list"),
+  stdout:   r"Available recipes:
+    hello a b='B\t' c='C' # this does a thing
+    this-recipe-is-very-very-very-important Z='\t z' # something else
+    x a b='B\t' c='C'     # this does another thing
+",
+  stderr:   "",
+  status:   EXIT_SUCCESS,
+}
+
 integration_test! {
   name:     show_suggestion,
   justfile: r#"