Add --dump option to print entire justfile (#67)

Already implemented Display for Justfile, so no reason not to expose it
to the user.

Also only allow one of --list, --dump, or --show, since they don't make
a lot of sense together.

src/app.rs

@@ -57,7 +57,22 @@ pub fn app() {
     .arg(Arg::with_name("list")
          .short("l")
          .long("list")
-         .help("Lists available recipes"))
+         .help("List available recipes")
+         .conflicts_with("dump")
+         .conflicts_with("show"))
+    .arg(Arg::with_name("dump")
+         .long("dump")
+         .help("Print entire justfile")
+         .conflicts_with("show")
+         .conflicts_with("list"))
+    .arg(Arg::with_name("show")
+         .short("s")
+         .long("show")
+         .takes_value(true)
+         .value_name("recipe")
+         .help("Show information about <recipe>")
+         .conflicts_with("dump")
+         .conflicts_with("list"))
     .arg(Arg::with_name("quiet")
          .short("q")
          .long("quiet")
@@ -74,19 +89,13 @@ pub fn app() {
          .possible_values(&["auto", "always", "never"])
          .default_value("auto")
          .help("Print colorful output"))
-    .arg(Arg::with_name("show")
-         .short("s")
-         .long("show")
-         .takes_value(true)
-         .value_name("recipe")
-         .help("Show information about <recipe>"))
     .arg(Arg::with_name("set")
          .long("set")
          .takes_value(true)
          .number_of_values(2)
          .value_names(&["variable", "value"])
          .multiple(true)
-         .help("set <variable> to <value>"))
+         .help("Set <variable> to <value>"))
     .arg(Arg::with_name("working-directory")
          .long("working-directory")
          .takes_value(true)
@@ -97,7 +106,7 @@ pub fn app() {
          .help("Use <justfile> as justfile. --working-directory must also be set"))
     .arg(Arg::with_name("arguments")
          .multiple(true)
-         .help("recipe(s) to run, defaults to the first recipe in the justfile"))
+         .help("The recipe(s) to run, defaults to the first recipe in the justfile"))
     .get_matches();
 
   // it is not obvious to me what we should do if only one of --justfile and
@@ -178,6 +187,11 @@ pub fn app() {
     process::exit(0);
   }
 
+  if matches.is_present("dump") {
+    println!("{}", justfile);
+    process::exit(0);
+  }
+
   if let Some(name) = matches.value_of("show") {
     match justfile.get(name) {
       Some(recipe) => {

src/integration.rs

@@ -266,29 +266,6 @@ recipe:
     "",
   );
 }
-/*
-#[test]
-fn debug() {
-  let text = 
-r#"hello = "foo"
-bar = hello + hello
-recipe:
- echo {{hello + "bar" + bar}}"#;
-  integration_test(
-    &["--debug"],
-    text,
-    0,
-    r#"bar = hello + hello # "foofoo"
-
-hello = "foo" # "foo"
-
-recipe:
-    echo {{hello + "bar" + bar # "foobarfoofoo"}}
-"#,
-    "",
-  );
-}
-*/
 
 #[test]
 fn status_passthrough() {
@@ -971,3 +948,19 @@ recipe:
   );
 }
 
+#[test]
+fn dump() {
+  let text ="
+recipe:
+ @exit 100";
+  integration_test(
+    &["--dump"],
+    text,
+    0,
+    "recipe:
+    @exit 100
+",
+    "",
+  );
+}
+