feat: add --importmap flag to deno bundle (#4651)

cli/flags.rs

@@ -374,6 +374,7 @@ fn install_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
 
 fn bundle_parse(flags: &mut Flags, matches: &clap::ArgMatches) {
   ca_file_arg_parse(flags, matches);
+  importmap_arg_parse(flags, matches);
 
   let source_file = matches.value_of("source_file").unwrap().to_string();
 
@@ -666,6 +667,7 @@ fn bundle_subcommand<'a, 'b>() -> App<'a, 'b> {
     )
     .arg(Arg::with_name("out_file").takes_value(true).required(false))
     .arg(ca_file_arg())
+    .arg(importmap_arg())
     .about("Bundle module and dependencies into single file")
     .long_about(
       "Output a single JavaScript file with all dependencies.

cli/tests/bundle_im.json

@@ -0,0 +1,5 @@
+{
+  "imports": {
+    "mod2": "./subdir/subdir2/mod2.ts"
+  }
+}

cli/tests/bundle_im.ts

@@ -0,0 +1,17 @@
+import { returnsFoo, printHello2 } from "mod2";
+
+export function returnsHi(): string {
+  return "Hi";
+}
+
+export function returnsFoo2(): string {
+  return returnsFoo();
+}
+
+export function printHello3(): void {
+  printHello2();
+}
+
+export function throwsError(): void {
+  throw Error("exception from mod1");
+}

cli/tests/integration_tests.rs

@@ -524,6 +524,50 @@ fn bundle_dynamic_import() {
   assert_eq!(output.stderr, b"");
 }
 
+#[test]
+fn bundle_import_map() {
+  let import = util::root_path().join("cli/tests/bundle_im.ts");
+  let import_map_path = util::root_path().join("cli/tests/bundle_im.json");
+  assert!(import.is_file());
+  let t = TempDir::new().expect("tempdir fail");
+  let bundle = t.path().join("import_map.bundle.js");
+  let mut deno = util::deno_cmd()
+    .current_dir(util::root_path())
+    .arg("bundle")
+    .arg("--importmap")
+    .arg(import_map_path)
+    .arg(import)
+    .arg(&bundle)
+    .spawn()
+    .expect("failed to spawn script");
+  let status = deno.wait().expect("failed to wait for the child process");
+  assert!(status.success());
+  assert!(bundle.is_file());
+
+  // Now we try to use that bundle from another module.
+  let test = t.path().join("test.js");
+  std::fs::write(
+    &test,
+    "
+      import { printHello3 } from \"./import_map.bundle.js\";
+      printHello3(); ",
+  )
+  .expect("error writing file");
+
+  let output = util::deno_cmd()
+    .current_dir(util::root_path())
+    .arg("run")
+    .arg(&test)
+    .output()
+    .expect("failed to spawn script");
+  // check the output of the test.ts program.
+  assert!(std::str::from_utf8(&output.stdout)
+    .unwrap()
+    .trim()
+    .ends_with("Hello"));
+  assert_eq!(output.stderr, b"");
+}
+
 #[test]
 fn repl_test_console_log() {
   let (out, err) = util::run_and_collect_output(