feat: parse flags after script name (denoland#2596)

cli/flags.rs

@@ -434,8 +434,11 @@ fn resolve_paths(paths: Vec<String>) -> Vec<String> {
 
 /// Parse ArgMatches into internal DenoFlags structure.
 /// This method should not make any side effects.
-pub fn parse_flags(matches: &ArgMatches) -> DenoFlags {
-  let mut flags = DenoFlags::default();
+pub fn parse_flags(
+  matches: &ArgMatches,
+  maybe_flags: Option<DenoFlags>,
+) -> DenoFlags {
+  let mut flags = maybe_flags.unwrap_or_default();
 
   if matches.is_present("log-level") {
     flags.log_level = match matches.value_of("log-level").unwrap() {
@@ -552,6 +555,56 @@ fn parse_run_args(mut flags: DenoFlags, matches: &ArgMatches) -> DenoFlags {
   flags
 }
 
+/// Parse vector or arguments as DenoFlags.
+///
+/// This is very specialized utility that parses arguments passed after script URL.
+///
+/// Only dash (eg. `-r`) and double dash (eg. `--reload`) arguments are supported.
+/// Arguments recognized as DenoFlags will be eaten.
+/// Parsing stops after double dash `--` argument.
+///
+/// NOTE: this method ignores `-h/--help` and `-v/--version` flags.
+fn parse_script_args(
+  args: Vec<String>,
+  mut flags: DenoFlags,
+) -> (Vec<String>, DenoFlags) {
+  let mut argv = vec![];
+  let mut seen_double_dash = false;
+
+  // we have to iterate and parse argument one by one because clap returns error on any
+  // unrecognized argument
+  for arg in args.iter() {
+    if seen_double_dash {
+      argv.push(arg.to_string());
+      continue;
+    }
+
+    if arg == "--" {
+      seen_double_dash = true;
+      argv.push(arg.to_string());
+      continue;
+    }
+
+    if !arg.starts_with('-') {
+      argv.push(arg.to_string());
+      continue;
+    }
+
+    let cli_app = create_cli_app();
+    // `get_matches_from_safe` returns error for `-h/-v` flags
+    let matches =
+      cli_app.get_matches_from_safe(vec!["deno".to_string(), arg.to_string()]);
+
+    if matches.is_ok() {
+      flags = parse_flags(&matches.unwrap(), Some(flags));
+    } else {
+      argv.push(arg.to_string());
+    }
+  }
+
+  (argv, flags)
+}
+
 /// Used for `deno fmt <files>...` subcommand
 const PRETTIER_URL: &str = "https://deno.land/std@v0.7.0/prettier/main.ts";
 /// Used for `deno install...` subcommand
@@ -603,7 +656,7 @@ pub fn flags_from_vec(
   let cli_app = create_cli_app();
   let matches = cli_app.get_matches_from(args);
   let mut argv: Vec<String> = vec!["deno".to_string()];
-  let mut flags = parse_flags(&matches.clone());
+  let mut flags = parse_flags(&matches.clone(), None);
 
   let subcommand = match matches.subcommand() {
     ("bundle", Some(bundle_match)) => {
@@ -711,6 +764,9 @@ pub fn flags_from_vec(
               .unwrap()
               .map(String::from)
               .collect();
+
+            let (script_args, flags_) = parse_script_args(script_args, flags);
+            flags = flags_;
             argv.extend(script_args);
           }
           DenoSubcommand::Run
@@ -746,6 +802,9 @@ pub fn flags_from_vec(
           .unwrap()
           .map(String::from)
           .collect();
+
+        let (script_args, flags_) = parse_script_args(script_args, flags);
+        flags = flags_;
         argv.extend(script_args);
       }
       DenoSubcommand::Run
@@ -933,14 +992,15 @@ mod tests {
 
   #[test]
   fn test_flags_from_vec_10() {
-    // notice that flags passed after script name will not
+    // notice that flags passed after double dash will not
     // be parsed to DenoFlags but instead forwarded to
     // script args as Deno.args
     let (flags, subcommand, argv) = flags_from_vec(svec![
       "deno",
       "run",
       "--allow-write",
       "script.ts",
+      "--",
       "-D",
       "--allow-net"
     ]);
@@ -952,7 +1012,7 @@ mod tests {
       }
     );
     assert_eq!(subcommand, DenoSubcommand::Run);
-    assert_eq!(argv, svec!["deno", "script.ts", "-D", "--allow-net"]);
+    assert_eq!(argv, svec!["deno", "script.ts", "--", "-D", "--allow-net"]);
   }
 
   #[test]
@@ -1436,4 +1496,43 @@ mod tests {
     assert_eq!(subcommand, DenoSubcommand::Completions);
     assert_eq!(argv, svec!["deno"])
   }
+
+  #[test]
+  fn test_flags_from_vec_33() {
+    let (flags, subcommand, argv) =
+      flags_from_vec(svec!["deno", "script.ts", "--allow-read", "--allow-net"]);
+    assert_eq!(
+      flags,
+      DenoFlags {
+        allow_net: true,
+        allow_read: true,
+        ..DenoFlags::default()
+      }
+    );
+    assert_eq!(subcommand, DenoSubcommand::Run);
+    assert_eq!(argv, svec!["deno", "script.ts"]);
+
+    let (flags, subcommand, argv) = flags_from_vec(svec![
+      "deno",
+      "--allow-read",
+      "run",
+      "script.ts",
+      "--allow-net",
+      "-r",
+      "--help",
+      "--foo",
+      "bar"
+    ]);
+    assert_eq!(
+      flags,
+      DenoFlags {
+        allow_net: true,
+        allow_read: true,
+        reload: true,
+        ..DenoFlags::default()
+      }
+    );
+    assert_eq!(subcommand, DenoSubcommand::Run);
+    assert_eq!(argv, svec!["deno", "script.ts", "--help", "--foo", "bar"]);
+  }
 }