fix(cli): Don't strip shebangs from modules (#13220)

Deno's module loader currently strips a shebang if a module file
starts with one. However, this is no longer necessary, since there is
a stage-3 TC39 that adds support for shebangs (or "hashbangs") to the
language (https://github.com/tc39/proposal-hashbang), and V8, `tsc`
and `swc` all support it.

Furthermore, stripping shebangs causes a correctness bug with JSON
modules, since a JSON file with a shebang should not parse as a JSON
module, yet it does with this stripping. This change fixes this.

7 files changed, 39 insertions, 0 deletions

diff --git a/cli/tests/integration/run_tests.rs b/cli/tests/integration/run_tests.rs
index f4793a969..bc137a7fd 100644
--- a/cli/tests/integration/run_tests.rs
+++ b/cli/tests/integration/run_tests.rs
@@ -1600,6 +1600,28 @@ itest!(jsx_import_source_error {
   exit_code: 1,
 });
 
+itest!(shebang_tsc {
+  args: "run --quiet shebang.ts",
+  output: "shebang.ts.out",
+});
+
+itest!(shebang_swc {
+  args: "run --quiet --no-check shebang.ts",
+  output: "shebang.ts.out",
+});
+
+itest!(shebang_with_json_imports_tsc {
+  args: "run --quiet import_assertions/json_with_shebang.ts",
+  output: "import_assertions/json_with_shebang.ts.out",
+  exit_code: 1,
+});
+
+itest!(shebang_with_json_imports_swc {
+  args: "run --quiet --no-check import_assertions/json_with_shebang.ts",
+  output: "import_assertions/json_with_shebang.ts.out",
+  exit_code: 1,
+});
+
 #[test]
 fn no_validate_asm() {
   let output = util::deno_cmd()
diff --git a/cli/tests/testdata/import_assertions/json_with_shebang.json b/cli/tests/testdata/import_assertions/json_with_shebang.json
new file mode 100644
index 000000000..b695e4457
--- /dev/null
+++ b/cli/tests/testdata/import_assertions/json_with_shebang.json
@@ -0,0 +1,4 @@
+#!/usr/env -S deno run
+{
+  "test": null
+}
diff --git a/cli/tests/testdata/import_assertions/json_with_shebang.ts b/cli/tests/testdata/import_assertions/json_with_shebang.ts
new file mode 100644
index 000000000..523bf8772
--- /dev/null
+++ b/cli/tests/testdata/import_assertions/json_with_shebang.ts
@@ -0,0 +1,3 @@
+import json from "./json_with_shebang.json" assert { type: "json" };
+
+console.log(json);
diff --git a/cli/tests/testdata/import_assertions/json_with_shebang.ts.out b/cli/tests/testdata/import_assertions/json_with_shebang.ts.out
new file mode 100644
index 000000000..ae5f3a65f
--- /dev/null
+++ b/cli/tests/testdata/import_assertions/json_with_shebang.ts.out
@@ -0,0 +1 @@
+error: Uncaught SyntaxError: Unexpected token # in JSON at position 0
diff --git a/cli/tests/testdata/shebang.ts b/cli/tests/testdata/shebang.ts
new file mode 100644
index 000000000..00feb2da0
--- /dev/null
+++ b/cli/tests/testdata/shebang.ts
@@ -0,0 +1,5 @@
+#!/usr/bin/env -S deno run
+
+import test from "./shebang2.ts";
+
+console.log(test as number);
diff --git a/cli/tests/testdata/shebang.ts.out b/cli/tests/testdata/shebang.ts.out
new file mode 100644
index 000000000..d81cc0710
--- /dev/null
+++ b/cli/tests/testdata/shebang.ts.out
@@ -0,0 +1 @@
+42
diff --git a/cli/tests/testdata/shebang2.ts b/cli/tests/testdata/shebang2.ts
new file mode 100644
index 000000000..da0d7bf0c
--- /dev/null
+++ b/cli/tests/testdata/shebang2.ts
@@ -0,0 +1,3 @@
+#!/usr/bin/env -S deno run
+
+export default 42;