feat(repl): run "deno repl" with no permissions (#16795)

This commit changes "deno repl" command to run with no permissions by
default and accept "--allow-*" flags. 

This change is dictated by the fact that currently there is no way to
run REPL with limited permissions. Technically it's a breaking 
change in the CLI command, but there's agreement in the team 
that it has merit and it's a good solution.

Running just "deno" command still starts the REPL with full permissions
allowed, but now a banner is printed to inform users about that:

5 files changed, 48 insertions, 63 deletions

diff --git a/cli/args/flags.rs b/cli/args/flags.rs
index 4296fbc77..7a4416cf5 100644
--- a/cli/args/flags.rs
+++ b/cli/args/flags.rs
@@ -163,6 +163,7 @@ pub struct LintFlags {
 pub struct ReplFlags {
   pub eval_files: Option<Vec<String>>,
   pub eval: Option<String>,
+  pub is_default_command: bool,
 }
 
 #[derive(Clone, Debug, Eq, PartialEq, Deserialize, Serialize)]
@@ -245,6 +246,7 @@ impl Default for DenoSubcommand {
     DenoSubcommand::Repl(ReplFlags {
       eval_files: None,
       eval: None,
+      is_default_command: true,
     })
   }
 }
@@ -624,6 +626,7 @@ pub fn flags_from_vec(args: Vec<String>) -> clap::Result<Flags> {
       ReplFlags {
         eval_files: None,
         eval: None,
+        is_default_command: true,
       },
     ),
   }
@@ -632,15 +635,18 @@ pub fn flags_from_vec(args: Vec<String>) -> clap::Result<Flags> {
 }
 
 fn handle_repl_flags(flags: &mut Flags, repl_flags: ReplFlags) {
+  // If user runs just `deno` binary we enter REPL and allow all permissions.
+  if repl_flags.is_default_command {
+    flags.allow_net = Some(vec![]);
+    flags.allow_env = Some(vec![]);
+    flags.allow_run = Some(vec![]);
+    flags.allow_read = Some(vec![]);
+    flags.allow_sys = Some(vec![]);
+    flags.allow_write = Some(vec![]);
+    flags.allow_ffi = Some(vec![]);
+    flags.allow_hrtime = true;
+  }
   flags.subcommand = DenoSubcommand::Repl(repl_flags);
-  flags.allow_net = Some(vec![]);
-  flags.allow_env = Some(vec![]);
-  flags.allow_run = Some(vec![]);
-  flags.allow_read = Some(vec![]);
-  flags.allow_sys = Some(vec![]);
-  flags.allow_write = Some(vec![]);
-  flags.allow_ffi = Some(vec![]);
-  flags.allow_hrtime = true;
 }
 
 fn clap_root(version: &str) -> Command {
@@ -1464,7 +1470,7 @@ Ignore linting a file by adding an ignore comment at the top of the file:
 }
 
 fn repl_subcommand<'a>() -> Command<'a> {
-  runtime_args(Command::new("repl"), false, true)
+  runtime_args(Command::new("repl"), true, true)
     .about("Read Eval Print Loop")
     .arg(
       Arg::new("eval-file")
@@ -1483,7 +1489,6 @@ fn repl_subcommand<'a>() -> Command<'a> {
         .takes_value(true)
         .value_name("code"),
     )
-    .arg(unsafely_ignore_certificate_errors_arg())
 }
 
 fn run_subcommand<'a>() -> Command<'a> {
@@ -2654,7 +2659,7 @@ fn lint_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
 }
 
 fn repl_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
-  runtime_args_parse(flags, matches, false, true);
+  runtime_args_parse(flags, matches, true, true);
   unsafely_ignore_certificate_errors_parse(flags, matches);
 
   let eval_files: Option<Vec<String>> = matches
@@ -2666,6 +2671,7 @@ fn repl_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
     ReplFlags {
       eval_files,
       eval: matches.value_of("eval").map(ToOwned::to_owned),
+      is_default_command: false,
     },
   );
 }
@@ -4276,7 +4282,8 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Repl(ReplFlags {
           eval_files: None,
-          eval: None
+          eval: None,
+          is_default_command: true,
         }),
         allow_net: Some(vec![]),
         unsafely_ignore_certificate_errors: None,
@@ -4295,13 +4302,14 @@ mod tests {
   #[test]
   fn repl_with_flags() {
     #[rustfmt::skip]
-    let r = flags_from_vec(svec!["deno", "repl", "--import-map", "import_map.json", "--no-remote", "--config", "tsconfig.json", "--no-check", "--reload", "--lock", "lock.json", "--lock-write", "--cert", "example.crt", "--cached-only", "--location", "https:foo", "--v8-flags=--help", "--seed", "1", "--inspect=127.0.0.1:9229", "--unsafely-ignore-certificate-errors"]);
+    let r = flags_from_vec(svec!["deno", "repl", "-A", "--import-map", "import_map.json", "--no-remote", "--config", "tsconfig.json", "--no-check", "--reload", "--lock", "lock.json", "--lock-write", "--cert", "example.crt", "--cached-only", "--location", "https:foo", "--v8-flags=--help", "--seed", "1", "--inspect=127.0.0.1:9229", "--unsafely-ignore-certificate-errors"]);
     assert_eq!(
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Repl(ReplFlags {
           eval_files: None,
-          eval: None
+          eval: None,
+          is_default_command: false,
         }),
         import_map_path: Some("import_map.json".to_string()),
         no_remote: true,
@@ -4316,6 +4324,7 @@ mod tests {
         v8_flags: svec!["--help", "--random-seed=1"],
         seed: Some(1),
         inspect: Some("127.0.0.1:9229".parse().unwrap()),
+        allow_all: true,
         allow_net: Some(vec![]),
         allow_env: Some(vec![]),
         allow_run: Some(vec![]),
@@ -4333,22 +4342,16 @@ mod tests {
   #[test]
   fn repl_with_eval_flag() {
     #[rustfmt::skip]
-    let r = flags_from_vec(svec!["deno", "repl", "--eval", "console.log('hello');"]);
+    let r = flags_from_vec(svec!["deno", "repl", "--allow-write", "--eval", "console.log('hello');"]);
     assert_eq!(
       r.unwrap(),
       Flags {
         subcommand: DenoSubcommand::Repl(ReplFlags {
           eval_files: None,
           eval: Some("console.log('hello');".to_string()),
+          is_default_command: false,
         }),
-        allow_net: Some(vec![]),
-        allow_env: Some(vec![]),
-        allow_run: Some(vec![]),
-        allow_read: Some(vec![]),
-        allow_sys: Some(vec![]),
         allow_write: Some(vec![]),
-        allow_ffi: Some(vec![]),
-        allow_hrtime: true,
         type_check_mode: TypeCheckMode::None,
         ..Flags::default()
       }
@@ -4369,15 +4372,8 @@ mod tests {
             "https://examples.deno.land/hello-world.ts".to_string()
           ]),
           eval: None,
+          is_default_command: false,
         }),
-        allow_net: Some(vec![]),
-        allow_env: Some(vec![]),
-        allow_run: Some(vec![]),
-        allow_read: Some(vec![]),
-        allow_sys: Some(vec![]),
-        allow_write: Some(vec![]),
-        allow_ffi: Some(vec![]),
-        allow_hrtime: true,
         type_check_mode: TypeCheckMode::None,
         ..Flags::default()
       }
@@ -5172,16 +5168,9 @@ mod tests {
         subcommand: DenoSubcommand::Repl(ReplFlags {
           eval_files: None,
           eval: Some("console.log('hello');".to_string()),
+          is_default_command: false,
         }),
         unsafely_ignore_certificate_errors: Some(vec![]),
-        allow_net: Some(vec![]),
-        allow_env: Some(vec![]),
-        allow_run: Some(vec![]),
-        allow_read: Some(vec![]),
-        allow_sys: Some(vec![]),
-        allow_write: Some(vec![]),
-        allow_ffi: Some(vec![]),
-        allow_hrtime: true,
         type_check_mode: TypeCheckMode::None,
         ..Flags::default()
       }
@@ -5246,7 +5235,8 @@ mod tests {
       Flags {
         subcommand: DenoSubcommand::Repl(ReplFlags {
           eval_files: None,
-          eval: None
+          eval: None,
+          is_default_command: false,
         }),
         unsafely_ignore_certificate_errors: Some(svec![
           "deno.land",
@@ -5256,14 +5246,6 @@ mod tests {
           "[::1]",
           "1.2.3.4"
         ]),
-        allow_net: Some(vec![]),
-        allow_env: Some(vec![]),
-        allow_run: Some(vec![]),
-        allow_read: Some(vec![]),
-        allow_sys: Some(vec![]),
-        allow_write: Some(vec![]),
-        allow_ffi: Some(vec![]),
-        allow_hrtime: true,
         type_check_mode: TypeCheckMode::None,
         ..Flags::default()
       }
diff --git a/cli/main.rs b/cli/main.rs
index 445649e5f..98700c2b7 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -585,13 +585,7 @@ async fn repl_command(
   )
   .await?;
   worker.setup_repl().await?;
-  tools::repl::run(
-    &ps,
-    worker.into_main_worker(),
-    repl_flags.eval_files,
-    repl_flags.eval,
-  )
-  .await
+  tools::repl::run(&ps, worker.into_main_worker(), repl_flags).await
 }
 
 async fn run_from_stdin(flags: Flags) -> Result<i32, AnyError> {
diff --git a/cli/tests/inspector_tests.rs b/cli/tests/inspector_tests.rs
index 8e5a8d1f6..0cf8cc3bb 100644
--- a/cli/tests/inspector_tests.rs
+++ b/cli/tests/inspector_tests.rs
@@ -557,6 +557,7 @@ mod inspector {
   async fn inspector_runtime_evaluate_does_not_crash() {
     let child = util::deno_cmd()
       .arg("repl")
+      .arg("--allow-read")
       .arg(inspect_flag_with_unique_port("--inspect"))
       .stdin(std::process::Stdio::piped())
       .stdout(std::process::Stdio::piped())
diff --git a/cli/tests/repl_tests.rs b/cli/tests/repl_tests.rs
index 136148d9f..4524b4097 100644
--- a/cli/tests/repl_tests.rs
+++ b/cli/tests/repl_tests.rs
@@ -460,9 +460,9 @@ mod repl {
 
   #[test]
   fn import() {
-    let (out, _) = util::run_and_collect_output(
+    let (out, _) = util::run_and_collect_output_with_args(
       true,
-      "repl",
+      vec![],
       Some(vec!["import('./subdir/auto_print_hello.ts')"]),
       Some(vec![("NO_COLOR".to_owned(), "1".to_owned())]),
       false,
@@ -472,9 +472,9 @@ mod repl {
 
   #[test]
   fn import_declarations() {
-    let (out, _) = util::run_and_collect_output(
+    let (out, _) = util::run_and_collect_output_with_args(
       true,
-      "repl",
+      vec!["repl", "--allow-read"],
       Some(vec!["import './subdir/auto_print_hello.ts';"]),
       Some(vec![("NO_COLOR".to_owned(), "1".to_owned())]),
       false,
@@ -796,7 +796,7 @@ mod repl {
   fn eval_file_flag_multiple_files() {
     let (out, err) = util::run_and_collect_output_with_args(
     true,
-    vec!["repl", "--eval-file=http://127.0.0.1:4545/repl/import_type.ts,./tsc/d.ts,http://127.0.0.1:4545/type_definitions/foo.js"],
+    vec!["repl", "--allow-read", "--eval-file=http://127.0.0.1:4545/repl/import_type.ts,./tsc/d.ts,http://127.0.0.1:4545/type_definitions/foo.js"],
     Some(vec!["b.method1=v4", "b.method1()+foo.toUpperCase()"]),
     None,
     true,
diff --git a/cli/tools/repl/mod.rs b/cli/tools/repl/mod.rs
index afbd39eff..502105139 100644
--- a/cli/tools/repl/mod.rs
+++ b/cli/tools/repl/mod.rs
@@ -1,5 +1,7 @@
 // Copyright 2018-2022 the Deno authors. All rights reserved. MIT license.
 
+use crate::args::ReplFlags;
+use crate::colors;
 use crate::proc_state::ProcState;
 use deno_core::error::AnyError;
 use deno_runtime::permissions::Permissions;
@@ -77,8 +79,7 @@ async fn read_eval_file(
 pub async fn run(
   ps: &ProcState,
   worker: MainWorker,
-  maybe_eval_files: Option<Vec<String>>,
-  maybe_eval: Option<String>,
+  repl_flags: ReplFlags,
 ) -> Result<i32, AnyError> {
   let mut repl_session = ReplSession::initialize(worker).await?;
   let mut rustyline_channel = rustyline_channel();
@@ -92,7 +93,7 @@ pub async fn run(
   let history_file_path = ps.dir.repl_history_file_path();
   let editor = ReplEditor::new(helper, history_file_path)?;
 
-  if let Some(eval_files) = maybe_eval_files {
+  if let Some(eval_files) = repl_flags.eval_files {
     for eval_file in eval_files {
       match read_eval_file(ps, &eval_file).await {
         Ok(eval_source) => {
@@ -114,7 +115,7 @@ pub async fn run(
     }
   }
 
-  if let Some(eval) = maybe_eval {
+  if let Some(eval) = repl_flags.eval {
     let output = repl_session.evaluate_line_and_get_output(&eval).await?;
     // only output errors
     if let EvaluationOutput::Error(error_text) = output {
@@ -127,6 +128,13 @@ pub async fn run(
   if !ps.options.is_quiet() {
     println!("Deno {}", crate::version::deno());
     println!("exit using ctrl+d, ctrl+c, or close()");
+    if repl_flags.is_default_command {
+      println!(
+        "{}",
+        colors::yellow("REPL is running with all permissions allowed.")
+      );
+      println!("To specify permissions, run `deno repl` with allow flags.")
+    }
   }
 
   loop {