chore: add DENO_FUTURE env var (#22318)

Closes https://github.com/denoland/deno/issues/22315

```
~> DENO_FUTURE=1 target/debug/deno

> globalThis.window
undefined
```

cli/args/mod.rs

@@ -987,6 +987,10 @@ impl CliOptions {
     }
   }
 
+  pub fn enable_future_features(&self) -> bool {
+    std::env::var("DENO_FUTURE").is_ok()
+  }
+
   pub fn resolve_main_module(&self) -> Result<ModuleSpecifier, AnyError> {
     match &self.flags.subcommand {
       DenoSubcommand::Bundle(bundle_flags) => {

cli/factory.rs

@@ -775,6 +775,7 @@ impl CliFactory {
       self.feature_checker().clone(),
       self.create_cli_main_worker_options()?,
       self.options.node_ipc_fd(),
+      self.options.enable_future_features(),
       // TODO(bartlomieju): temporarily disabled
       // self.options.disable_deprecated_api_warning,
       true,

cli/standalone/mod.rs

@@ -551,6 +551,7 @@ pub async fn run(
       create_coverage_collector: None,
     },
     None,
+    false,
     // TODO(bartlomieju): temporarily disabled
     // metadata.disable_deprecated_api_warning,
     true,

cli/worker.rs

@@ -144,6 +144,7 @@ struct SharedWorkerState {
   maybe_lockfile: Option<Arc<Mutex<Lockfile>>>,
   feature_checker: Arc<FeatureChecker>,
   node_ipc: Option<i64>,
+  enable_future_features: bool,
   disable_deprecated_api_warning: bool,
   verbose_deprecated_api_warning: bool,
 }
@@ -424,6 +425,7 @@ impl CliMainWorkerFactory {
     feature_checker: Arc<FeatureChecker>,
     options: CliMainWorkerOptions,
     node_ipc: Option<i64>,
+    enable_future_features: bool,
     disable_deprecated_api_warning: bool,
     verbose_deprecated_api_warning: bool,
   ) -> Self {
@@ -446,6 +448,7 @@ impl CliMainWorkerFactory {
         maybe_lockfile,
         feature_checker,
         node_ipc,
+        enable_future_features,
         disable_deprecated_api_warning,
         verbose_deprecated_api_warning,
       }),
@@ -612,6 +615,7 @@ impl CliMainWorkerFactory {
         node_ipc_fd: shared.node_ipc,
         disable_deprecated_api_warning: shared.disable_deprecated_api_warning,
         verbose_deprecated_api_warning: shared.verbose_deprecated_api_warning,
+        future: shared.enable_future_features,
       },
       extensions: custom_extensions,
       startup_snapshot: crate::js::deno_isolate_init(),
@@ -818,6 +822,7 @@ fn create_web_worker_callback(
         node_ipc_fd: None,
         disable_deprecated_api_warning: shared.disable_deprecated_api_warning,
         verbose_deprecated_api_warning: shared.verbose_deprecated_api_warning,
+        future: false,
       },
       extensions: vec![],
       startup_snapshot: crate::js::deno_isolate_init(),

runtime/js/99_main.js

@@ -647,6 +647,7 @@ function bootstrapMainRuntime(runtimeOptions) {
     6: maybeBinaryNpmCommandName,
     7: shouldDisableDeprecatedApiWarning,
     8: shouldUseVerboseDeprecatedApiWarning,
+    9: future,
   } = runtimeOptions;
 
   removeImportedOps();
@@ -769,6 +770,10 @@ function bootstrapMainRuntime(runtimeOptions) {
   if (nodeBootstrap) {
     nodeBootstrap(hasNodeModulesDir, maybeBinaryNpmCommandName);
   }
+
+  if (future) {
+    delete globalThis.window;
+  }
 }
 
 function bootstrapWorkerRuntime(

runtime/worker_bootstrap.rs

@@ -62,6 +62,7 @@ pub struct BootstrapOptions {
   pub node_ipc_fd: Option<i64>,
   pub disable_deprecated_api_warning: bool,
   pub verbose_deprecated_api_warning: bool,
+  pub future: bool,
 }
 
 impl Default for BootstrapOptions {
@@ -92,6 +93,7 @@ impl Default for BootstrapOptions {
       node_ipc_fd: None,
       disable_deprecated_api_warning: false,
       verbose_deprecated_api_warning: false,
+      future: false,
     }
   }
 }
@@ -125,6 +127,8 @@ struct BootstrapV8<'a>(
   bool,
   // verbose_deprecated_api_warning
   bool,
+  // future
+  bool,
 );
 
 impl BootstrapOptions {
@@ -146,6 +150,7 @@ impl BootstrapOptions {
       self.maybe_binary_npm_command_name.as_deref(),
       self.disable_deprecated_api_warning,
       self.verbose_deprecated_api_warning,
+      self.future,
     );
 
     bootstrap.serialize(ser).unwrap()

test_util/src/builders.rs

@@ -166,6 +166,11 @@ impl TestContextBuilder {
     self
   }
 
+  pub fn add_future_env_vars(mut self) -> Self {
+    self = self.env("DENO_FUTURE", "1");
+    self
+  }
+
   pub fn add_jsr_env_vars(mut self) -> Self {
     for (key, value) in env_vars_for_jsr_tests() {
       self = self.env(key, value);

tests/integration/run_tests.rs

@@ -1711,6 +1711,16 @@ fn type_directives_js_main() {
   assert_not_contains!(output.combined_output(), "type_reference.d.ts");
 }
 
+#[test]
+fn test_deno_futures_env() {
+  let context = TestContextBuilder::new().add_future_env_vars().build();
+  let output = context
+    .new_command()
+    .args("run --quiet --reload run/deno_futures_env.ts")
+    .run();
+  output.assert_exit_code(0);
+}
+
 itest!(type_directives_redirect {
   args: "run --reload --check run/type_directives_redirect.ts",
   output: "run/type_directives_redirect.ts.out",

tests/testdata/run/deno_futures_env.ts

@@ -0,0 +1,3 @@
+if (typeof window !== "undefined") {
+  throw new Error("Window global available");
+}