feat: Expand 'imports' section of deno.json (#22087)

This commit adds automatic expansion of "imports" field in "deno.json"
file.

If "npm:" or "jsr:" imports are encountered we automatically try to add
a "directory" remapping.

Previously users had to specify entries for both `foo` and `foo/` to be
able to import like
`import { symbol1 } from "foo";` and `import { symbol2 } from
"foo/some_file.js"`:
```
{
  "imports": {
    "foo": "npm:@foo/bar",
    "foo/": "npm:/@foo/bar/",
}
```

With this change users can only add entry for `foo`:
```
{
  "imports": {
    "foo": "npm:@foo/bar",
}
```
The entry for `foo/` will be provided automatically.

Similarly if user provides "directory" remapping explicitly, we will not
overwrite it.

5 files changed, 110 insertions, 6 deletions

diff --git a/cli/args/mod.rs b/cli/args/mod.rs
index 13ee9eeef..1e5d8754d 100644
--- a/cli/args/mod.rs
+++ b/cli/args/mod.rs
@@ -889,7 +889,19 @@ impl CliOptions {
         .members
         .iter()
         .map(|member| {
-          let import_map_value = member.config_file.to_import_map_value();
+          let mut import_map_value = member.config_file.to_import_map_value();
+
+          let expanded_import_map_value = ::import_map::ext::expand_imports(
+            ::import_map::ext::ImportMapConfig {
+              base_url: member.config_file.specifier.clone(),
+              import_map_value: import_map_value.clone(),
+            },
+          );
+
+          import_map_value
+            .as_object_mut()
+            .unwrap()
+            .insert("imports".to_string(), expanded_import_map_value);
           ::import_map::ext::ImportMapConfig {
             base_url: member.config_file.specifier.clone(),
             import_map_value,
@@ -906,12 +918,24 @@ impl CliOptions {
           "Workspace config generated this import map {}",
           serde_json::to_string_pretty(&import_map).unwrap()
         );
-        return import_map::import_map_from_value(
+        let maybe_import_map_result = import_map::import_map_from_value(
           // TODO(bartlomieju): maybe should be stored on the workspace config?
           &self.maybe_config_file.as_ref().unwrap().specifier,
           import_map,
         )
         .map(Some);
+
+        return match maybe_import_map_result {
+          Ok(maybe_import_map) => {
+            if let Some(mut import_map) = maybe_import_map {
+              import_map.ext_expand_imports();
+              Ok(Some(import_map))
+            } else {
+              Ok(None)
+            }
+          }
+          Err(err) => Err(err),
+        };
       }
     }
 
@@ -919,7 +943,8 @@ impl CliOptions {
       Some(specifier) => specifier,
       None => return Ok(None),
     };
-    resolve_import_map_from_specifier(
+
+    let maybe_import_map_result = resolve_import_map_from_specifier(
       &import_map_specifier,
       self.maybe_config_file().as_ref(),
       file_fetcher,
@@ -928,7 +953,22 @@ impl CliOptions {
     .with_context(|| {
       format!("Unable to load '{import_map_specifier}' import map")
     })
-    .map(Some)
+    .map(Some);
+
+    match maybe_import_map_result {
+      Ok(maybe_import_map) => {
+        if let Some(mut import_map) = maybe_import_map {
+          let url = import_map.base_url().as_str();
+          if url.ends_with("deno.json") || url.ends_with("deno.jsonc") {
+            import_map.ext_expand_imports();
+          }
+          Ok(Some(import_map))
+        } else {
+          Ok(None)
+        }
+      }
+      Err(err) => Err(err),
+    }
   }
 
   pub fn node_ipc_fd(&self) -> Option<i64> {
diff --git a/cli/tests/integration/run_tests.rs b/cli/tests/integration/run_tests.rs
index 6c82cfeec..b8acce94d 100644
--- a/cli/tests/integration/run_tests.rs
+++ b/cli/tests/integration/run_tests.rs
@@ -5113,3 +5113,64 @@ itest!(warn_on_deprecated_api_with_env_var {
   http_server: true,
   exit_code: 0,
 });
+
+#[test]
+fn deno_json_imports_expand() {
+  let test_context = TestContextBuilder::for_npm().use_temp_cwd().build();
+  let dir = test_context.temp_dir();
+  dir.write(
+    "deno.json",
+    r#"{
+    "imports": {
+      "basic": "npm:@denotest/esm-basic"
+    }
+}"#,
+  );
+
+  dir.write(
+    "main.ts",
+    r#"
+// import map should resolve
+import { setValue, getValue } from "basic";
+// this entry should have been added automatically
+import { hello } from "basic/other.mjs";
+
+setValue(5);
+console.log(getValue());
+console.log(hello());
+"#,
+  );
+  let output = test_context.new_command().args("run main.ts").run();
+  output.assert_matches_text("[WILDCARD]5\nhello, world!\n");
+}
+
+#[test]
+fn deno_json_imports_expand_doesnt_overwrite_existing_entries() {
+  let test_context = TestContextBuilder::for_npm().use_temp_cwd().build();
+  let dir = test_context.temp_dir();
+  dir.write(
+    "deno.json",
+    r#"{
+    "imports": {
+      "basic": "npm:@denotest/esm-basic",
+      "basic/": "npm:/@denotest/sub-folders/folder_index_js/"
+    }
+}"#,
+  );
+
+  dir.write(
+    "main.ts",
+    r#"
+// import map should resolve
+import { setValue, getValue } from "basic";
+// this entry should map to explicitly specified "basic/" mapping
+import { add } from "basic/index.js";
+
+setValue(5);
+console.log(getValue());
+console.log(add(3, 4));
+"#,
+  );
+  let output = test_context.new_command().args("run main.ts").run();
+  output.assert_matches_text("[WILDCARD]5\n7\n");
+}
diff --git a/cli/tests/testdata/compile/npm_fs/main.ts b/cli/tests/testdata/compile/npm_fs/main.ts
index f9951d7a4..6361610a9 100644
--- a/cli/tests/testdata/compile/npm_fs/main.ts
+++ b/cli/tests/testdata/compile/npm_fs/main.ts
@@ -154,7 +154,7 @@ await assert.rejects(
 }
 
 // read dir
-const readDirNames = ["main.d.mts", "main.mjs", "package.json"];
+const readDirNames = ["main.d.mts", "main.mjs", "other.mjs", "package.json"];
 {
   const names = Array.from(Deno.readDirSync(dirPath))
     .map((e) => e.name);
diff --git a/cli/tests/testdata/npm/registry/@denotest/esm-basic/1.0.0/other.mjs b/cli/tests/testdata/npm/registry/@denotest/esm-basic/1.0.0/other.mjs
new file mode 100644
index 000000000..00ed99da4
--- /dev/null
+++ b/cli/tests/testdata/npm/registry/@denotest/esm-basic/1.0.0/other.mjs
@@ -0,0 +1,3 @@
+export function hello() {
+    return "hello, world!";
+}
\ No newline at end of file
diff --git a/cli/tests/testdata/package_json/basic/main.info.out b/cli/tests/testdata/package_json/basic/main.info.out
index b283a0ee0..892c0612a 100644
--- a/cli/tests/testdata/package_json/basic/main.info.out
+++ b/cli/tests/testdata/package_json/basic/main.info.out
@@ -5,4 +5,4 @@ size: [WILDCARD]
 
 file:///[WILDCARD]/main.ts (63B)
 └─┬ file:///[WILDCARD]/lib.ts (166B)
-  └── npm:/@denotest/esm-basic@1.0.0 (416B)
+  └── npm:/@denotest/esm-basic@1.0.0 (471B)