feat(unstable/fmt): move yaml formatting behind unstable flag (#24848)

This moves YAML formatting behind an unstable flag for Deno 1.46. This
will make it opt-in to start and then we can remove the flag to make it
on by default in version of Deno after that.

This can be specified by doing `deno fmt --unstable-yaml` or by
specifying the following in a deno.json file:

```json
{
  "unstable": ["fmt-yaml"]
}
```

1 files changed, 27 insertions, 2 deletions

diff --git a/cli/args/flags.rs b/cli/args/flags.rs
index 6affa9f08..e283abc24 100644
--- a/cli/args/flags.rs
+++ b/cli/args/flags.rs
@@ -200,6 +200,7 @@ pub struct FmtFlags {
   pub prose_wrap: Option<String>,
   pub no_semicolons: Option<bool>,
   pub watch: Option<WatchFlags>,
+  pub unstable_yaml: bool,
 }
 
 impl FmtFlags {
@@ -2074,6 +2075,13 @@ Ignore formatting a file by adding an ignore comment at the top of the file:
               "Don't use semicolons except where necessary. Defaults to false.",
             ),
         )
+        .arg(
+          Arg::new("unstable-yaml")
+            .long("unstable-yaml")
+            .help("Enable formatting YAML files.")
+            .value_parser(FalseyValueParser::new())
+            .action(ArgAction::SetTrue),
+        )
     })
 }
 
@@ -4088,6 +4096,7 @@ fn fmt_parse(flags: &mut Flags, matches: &mut ArgMatches) {
   let single_quote = matches.remove_one::<bool>("single-quote");
   let prose_wrap = matches.remove_one::<String>("prose-wrap");
   let no_semicolons = matches.remove_one::<bool>("no-semicolons");
+  let unstable_yaml = matches.get_flag("unstable-yaml");
 
   flags.subcommand = DenoSubcommand::Fmt(FmtFlags {
     check: matches.get_flag("check"),
@@ -4099,6 +4108,7 @@ fn fmt_parse(flags: &mut Flags, matches: &mut ArgMatches) {
     prose_wrap,
     no_semicolons,
     watch: watch_arg_parse(matches),
+    unstable_yaml,
   });
 }
 
@@ -5781,6 +5791,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Default::default(),
         }),
         ext: Some("ts".to_string()),
@@ -5804,6 +5815,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Default::default(),
         }),
         ext: Some("ts".to_string()),
@@ -5827,6 +5839,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Default::default(),
         }),
         ext: Some("ts".to_string()),
@@ -5850,6 +5863,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Some(Default::default()),
         }),
         ext: Some("ts".to_string()),
@@ -5857,8 +5871,13 @@ mod tests {
       }
     );
 
-    let r =
-      flags_from_vec(svec!["deno", "fmt", "--watch", "--no-clear-screen"]);
+    let r = flags_from_vec(svec![
+      "deno",
+      "fmt",
+      "--watch",
+      "--no-clear-screen",
+      "--unstable-yaml"
+    ]);
     assert_eq!(
       r.unwrap(),
       Flags {
@@ -5874,6 +5893,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: true,
           watch: Some(WatchFlags {
             hmr: false,
             no_clear_screen: true,
@@ -5908,6 +5928,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Some(Default::default()),
         }),
         ext: Some("ts".to_string()),
@@ -5931,6 +5952,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Default::default(),
         }),
         ext: Some("ts".to_string()),
@@ -5962,6 +5984,7 @@ mod tests {
           single_quote: None,
           prose_wrap: None,
           no_semicolons: None,
+          unstable_yaml: false,
           watch: Some(Default::default()),
         }),
         config_flag: ConfigFlag::Path("deno.jsonc".to_string()),
@@ -5998,6 +6021,7 @@ mod tests {
           single_quote: Some(true),
           prose_wrap: Some("never".to_string()),
           no_semicolons: Some(true),
+          unstable_yaml: false,
           watch: Default::default(),
         }),
         ext: Some("ts".to_string()),
@@ -6028,6 +6052,7 @@ mod tests {
           single_quote: Some(false),
           prose_wrap: None,
           no_semicolons: Some(false),
+          unstable_yaml: false,
           watch: Default::default(),
         }),
         ext: Some("ts".to_string()),