1 files changed, 40 insertions, 0 deletions
diff --git a/cli/args/package_json.rs b/cli/args/package_json.rs
index 76d353c5e..73bcfb582 100644
--- a/cli/args/package_json.rs
+++ b/cli/args/package_json.rs
@@ -1,6 +1,8 @@
 // Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
 
 use std::collections::HashMap;
+use std::path::Path;
+use std::path::PathBuf;
 
 use deno_core::anyhow::anyhow;
 use deno_core::anyhow::bail;
@@ -83,6 +85,44 @@ pub fn get_local_package_json_version_reqs(
   Ok(result)
 }
 
+/// Attempts to discover the package.json file, maybe stopping when it
+/// reaches the specified `maybe_stop_at` directory.
+pub fn discover_from(
+  start: &Path,
+  maybe_stop_at: Option<PathBuf>,
+) -> Result<Option<PackageJson>, AnyError> {
+  const PACKAGE_JSON_NAME: &str = "package.json";
+
+  // note: ancestors() includes the `start` path
+  for ancestor in start.ancestors() {
+    let path = ancestor.join(PACKAGE_JSON_NAME);
+
+    let source = match std::fs::read_to_string(&path) {
+      Ok(source) => source,
+      Err(err) if err.kind() == std::io::ErrorKind::NotFound => {
+        if let Some(stop_at) = maybe_stop_at.as_ref() {
+          if ancestor == stop_at {
+            break;
+          }
+        }
+        continue;
+      }
+      Err(err) => bail!(
+        "Error loading package.json at {}. {:#}",
+        path.display(),
+        err
+      ),
+    };
+
+    let package_json = PackageJson::load_from_string(path.clone(), source)?;
+    log::debug!("package.json file found at '{}'", path.display());
+    return Ok(Some(package_json));
+  }
+
+  log::debug!("No package.json file found");
+  Ok(None)
+}
+
 #[cfg(test)]
 mod test {
   use pretty_assertions::assert_eq;