feat: add --ext flag to deno eval (#9295)

This PR deprecates the "--ts"/"-T" flag of "deno eval" (which will later be removed in 2.0)
and introduces "--ext" which is used by "deno fmt" for content type selection. 
This is to ensure we have a single flag that can be used across subcommands 
to select the language (JS/TS).

cli/flags.rs

@@ -44,7 +44,7 @@ pub enum DenoSubcommand {
   Eval {
     print: bool,
     code: String,
-    as_typescript: bool,
+    ext: String,
   },
   Fmt {
     check: bool,
@@ -525,7 +525,14 @@ fn eval_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   flags.allow_write = Some(vec![]);
   flags.allow_plugin = true;
   flags.allow_hrtime = true;
+  // TODO(@satyarohith): remove this flag in 2.0.
   let as_typescript = matches.is_present("ts");
+  let ext = if as_typescript {
+    "ts".to_string()
+  } else {
+    matches.value_of("ext").unwrap().to_string()
+  };
+
   let print = matches.is_present("print");
   let mut code: Vec<String> = matches
     .values_of("code_arg")
@@ -538,11 +545,7 @@ fn eval_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   for v in code_args {
     flags.argv.push(v);
   }
-  flags.subcommand = DenoSubcommand::Eval {
-    print,
-    code,
-    as_typescript,
-  };
+  flags.subcommand = DenoSubcommand::Eval { print, code, ext };
 }
 
 fn info_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
@@ -999,17 +1002,27 @@ fn eval_subcommand<'a, 'b>() -> App<'a, 'b> {
   deno eval \"console.log('hello world')\"
 
 To evaluate as TypeScript:
-  deno eval -T \"const v: string = 'hello'; console.log(v)\"
+  deno eval --ext=ts \"const v: string = 'hello'; console.log(v)\"
 
 This command has implicit access to all permissions (--allow-all).",
     )
     .arg(
+      // TODO(@satyarohith): remove this argument in 2.0.
       Arg::with_name("ts")
         .long("ts")
         .short("T")
         .help("Treat eval input as TypeScript")
         .takes_value(false)
-        .multiple(false),
+        .multiple(false)
+        .hidden(true),
+    )
+    .arg(
+      Arg::with_name("ext")
+        .long("ext")
+        .help("Set standard input (stdin) content type")
+        .takes_value(true)
+        .default_value("js")
+        .possible_values(&["ts", "tsx", "js", "jsx"]),
     )
     .arg(
       Arg::with_name("print")
@@ -2296,7 +2309,7 @@ mod tests {
         subcommand: DenoSubcommand::Eval {
           print: false,
           code: "'console.log(\"hello\")'".to_string(),
-          as_typescript: false,
+          ext: "js".to_string(),
         },
         allow_net: Some(vec![]),
         allow_env: true,
@@ -2319,7 +2332,7 @@ mod tests {
         subcommand: DenoSubcommand::Eval {
           print: true,
           code: "1+2".to_string(),
-          as_typescript: false,
+          ext: "js".to_string(),
         },
         allow_net: Some(vec![]),
         allow_env: true,
@@ -2343,7 +2356,7 @@ mod tests {
         subcommand: DenoSubcommand::Eval {
           print: false,
           code: "'console.log(\"hello\")'".to_string(),
-          as_typescript: true,
+          ext: "ts".to_string(),
         },
         allow_net: Some(vec![]),
         allow_env: true,
@@ -2367,7 +2380,7 @@ mod tests {
         subcommand: DenoSubcommand::Eval {
           print: false,
           code: "42".to_string(),
-          as_typescript: false,
+          ext: "js".to_string(),
         },
         unstable: true,
         import_map_path: Some("import_map.json".to_string()),
@@ -2410,7 +2423,7 @@ mod tests {
         subcommand: DenoSubcommand::Eval {
           print: false,
           code: "console.log(Deno.args)".to_string(),
-          as_typescript: false,
+          ext: "js".to_string(),
         },
         argv: svec!["arg1", "arg2"],
         allow_net: Some(vec![]),

cli/main.rs

@@ -472,7 +472,7 @@ async fn cache_command(
 async fn eval_command(
   flags: Flags,
   code: String,
-  as_typescript: bool,
+  ext: String,
   print: bool,
 ) -> Result<(), AnyError> {
   // Force TypeScript compile.
@@ -492,10 +492,14 @@ async fn eval_command(
   let file = File {
     local: main_module.clone().to_file_path().unwrap(),
     maybe_types: None,
-    media_type: if as_typescript {
+    media_type: if ext.as_str() == "ts" {
       MediaType::TypeScript
-    } else {
+    } else if ext.as_str() == "tsx" {
+      MediaType::TSX
+    } else if ext.as_str() == "js" {
       MediaType::JavaScript
+    } else {
+      MediaType::JSX
     },
     source: String::from_utf8(source_code)?,
     specifier: main_module.clone(),
@@ -1154,11 +1158,9 @@ fn get_subcommand(
       filter,
       private,
     } => doc_command(flags, source_file, json, filter, private).boxed_local(),
-    DenoSubcommand::Eval {
-      print,
-      code,
-      as_typescript,
-    } => eval_command(flags, code, as_typescript, print).boxed_local(),
+    DenoSubcommand::Eval { print, code, ext } => {
+      eval_command(flags, code, ext, print).boxed_local()
+    }
     DenoSubcommand::Cache { files } => {
       cache_command(flags, files).boxed_local()
     }

cli/tests/integration_tests.rs

@@ -2514,7 +2514,7 @@ console.log("finish");
 
   // Ugly parentheses due to whitespace delimiting problem.
   itest!(_030_eval_ts {
-    args: "eval --quiet -T console.log((123)as(number))", // 'as' is a TS keyword only
+    args: "eval --quiet --ext=ts console.log((123)as(number))", // 'as' is a TS keyword only
     output: "030_eval_ts.out",
   });