1 files changed, 57 insertions, 7 deletions

diff --git a/cli/main.rs b/cli/main.rs
index 0435775ad..689d5c634 100644
--- a/cli/main.rs
+++ b/cli/main.rs
@@ -43,6 +43,7 @@ use crate::file_watcher::ResolutionResult;
 use crate::flags::BenchFlags;
 use crate::flags::BundleFlags;
 use crate::flags::CacheFlags;
+use crate::flags::CheckFlags;
 use crate::flags::CompileFlags;
 use crate::flags::CompletionsFlags;
 use crate::flags::CoverageFlags;
@@ -51,6 +52,7 @@ use crate::flags::DocFlags;
 use crate::flags::EvalFlags;
 use crate::flags::Flags;
 use crate::flags::FmtFlags;
+use crate::flags::FutureTypeCheckMode;
 use crate::flags::InfoFlags;
 use crate::flags::InstallFlags;
 use crate::flags::LintFlags;
@@ -58,7 +60,7 @@ use crate::flags::ReplFlags;
 use crate::flags::RunFlags;
 use crate::flags::TaskFlags;
 use crate::flags::TestFlags;
-use crate::flags::TypecheckMode;
+use crate::flags::TypeCheckMode;
 use crate::flags::UninstallFlags;
 use crate::flags::UpgradeFlags;
 use crate::flags::VendorFlags;
@@ -585,6 +587,31 @@ async fn cache_command(
   Ok(0)
 }
 
+async fn check_command(
+  flags: Flags,
+  check_flags: CheckFlags,
+) -> Result<i32, AnyError> {
+  // NOTE(bartlomieju): currently just an alias for `deno cache`, but
+  // it will be changed in Deno 2.0.
+  let mut flags = flags.clone();
+
+  // In `deno check` the default mode is to check only
+  // local modules, with `--remote` we check remote modules too.
+  flags.type_check_mode = if check_flags.remote {
+    TypeCheckMode::All
+  } else {
+    TypeCheckMode::Local
+  };
+
+  cache_command(
+    flags,
+    CacheFlags {
+      files: check_flags.files,
+    },
+  )
+  .await
+}
+
 async fn eval_command(
   flags: Flags,
   eval_flags: EvalFlags,
@@ -679,12 +706,12 @@ async fn create_graph_and_maybe_check(
     .unwrap_or(false);
   graph_valid(
     &graph,
-    ps.flags.typecheck_mode != TypecheckMode::None,
+    ps.flags.type_check_mode != TypeCheckMode::None,
     check_js,
   )?;
   graph_lock_or_exit(&graph);
 
-  if ps.flags.typecheck_mode != TypecheckMode::None {
+  if ps.flags.type_check_mode != TypeCheckMode::None {
     let lib = if ps.flags.unstable {
       emit::TypeLib::UnstableDenoWindow
     } else {
@@ -708,7 +735,7 @@ async fn create_graph_and_maybe_check(
       Arc::new(RwLock::new(graph.as_ref().into())),
       &mut cache,
       emit::CheckOptions {
-        typecheck_mode: ps.flags.typecheck_mode.clone(),
+        type_check_mode: ps.flags.type_check_mode.clone(),
         debug,
         emit_with_diagnostics: false,
         maybe_config_specifier,
@@ -739,7 +766,7 @@ fn bundle_module_graph(
     ps.maybe_config_file.as_ref(),
     None,
   )?;
-  if flags.typecheck_mode == TypecheckMode::None {
+  if flags.type_check_mode == TypeCheckMode::None {
     if let Some(ignored_options) = maybe_ignored_options {
       eprintln!("{}", ignored_options);
     }
@@ -1010,7 +1037,7 @@ async fn run_with_watch(flags: Flags, script: String) -> Result<i32, AnyError> {
         .unwrap_or(false);
       graph_valid(
         &graph,
-        ps.flags.typecheck_mode != flags::TypecheckMode::None,
+        ps.flags.type_check_mode != flags::TypeCheckMode::None,
         check_js,
       )?;
 
@@ -1140,6 +1167,11 @@ async fn run_command(
   flags: Flags,
   run_flags: RunFlags,
 ) -> Result<i32, AnyError> {
+  if !flags.has_check_flag && flags.type_check_mode == TypeCheckMode::All {
+    info!("{} In future releases `deno run` will not automatically type check without the --check flag. 
+To opt into this new behavior now, specify DENO_FUTURE_CHECK=1.", colors::yellow("Warning"));
+  }
+
   // Read script content from stdin
   if run_flags.script == "-" {
     return run_from_stdin(flags).await;
@@ -1349,6 +1381,9 @@ fn get_subcommand(
     DenoSubcommand::Cache(cache_flags) => {
       cache_command(flags, cache_flags).boxed_local()
     }
+    DenoSubcommand::Check(check_flags) => {
+      check_command(flags, check_flags).boxed_local()
+    }
     DenoSubcommand::Compile(compile_flags) => {
       compile_command(flags, compile_flags).boxed_local()
     }
@@ -1458,7 +1493,7 @@ pub fn main() {
     // TODO(bartlomieju): doesn't handle exit code set by the runtime properly
     unwrap_or_exit(standalone_res);
 
-    let flags = match flags::flags_from_vec(args) {
+    let mut flags = match flags::flags_from_vec(args) {
       Ok(flags) => flags,
       Err(err @ clap::Error { .. })
         if err.kind() == clap::ErrorKind::DisplayHelp
@@ -1475,6 +1510,21 @@ pub fn main() {
 
     logger::init(flags.log_level);
 
+    // TODO(bartlomieju): remove once type checking is skipped by default (probably
+    // in 1.23).
+    // If this env var is set we're gonna override default behavior of type checking
+    // and use behavior defined by the `--check` flag.
+    let future_check_env_var = env::var("DENO_FUTURE_CHECK").ok();
+    if let Some(env_var) = future_check_env_var {
+      if env_var == "1" {
+        flags.type_check_mode = match &flags.future_type_check_mode {
+          FutureTypeCheckMode::None => TypeCheckMode::None,
+          FutureTypeCheckMode::All => TypeCheckMode::All,
+          FutureTypeCheckMode::Local => TypeCheckMode::Local,
+        }
+      }
+    }
+
     let exit_code = get_subcommand(flags).await;
 
     exit_code