From 9b725aa97b818734c477a5ada282d3537c7189a5 Mon Sep 17 00:00:00 2001
From: Dobes Vandermeer <dobes@formative.com>
Date: Wed, 14 May 2025 14:11:23 -0700
Subject: [PATCH 1/2] Defend against missing files in the hashing logic

If a file is missing while calculating file hashes, use stub values instead of exiting with an error.
---
 packages/hasher/src/FileHasher.ts | 26 +++++++++++++++++++-------
 1 file changed, 19 insertions(+), 7 deletions(-)

diff --git a/packages/hasher/src/FileHasher.ts b/packages/hasher/src/FileHasher.ts
index 1f7ebc684..5ad41660b 100644
--- a/packages/hasher/src/FileHasher.ts
+++ b/packages/hasher/src/FileHasher.ts
@@ -94,7 +94,7 @@ export class FileHasher {
     const stats = stat(files, { cwd: this.options.root }) ?? {};
 
     for (const file of files) {
-      const stat = stats[file];
+      const stat = stats[file] || { mtime: 0n, size: 0 };
 
       const info = this.#store[file];
       if (info && stat.mtime === info.mtime && stat.size == info.size) {
@@ -107,12 +107,24 @@ export class FileHasher {
     const updatedHashes = fastHash(updatedFiles, { cwd: this.options.root, concurrency: 4 }) ?? {};
 
     for (const [file, hash] of Object.entries(updatedHashes)) {
-      const stat = fs.statSync(path.join(this.options.root, file), { bigint: true });
-      this.#store[file] = {
-        mtime: stat.mtimeMs,
-        size: Number(stat.size),
-        hash: hash ?? "",
-      };
+      try {
+        const stat = fs.statSync(path.join(this.options.root, file), { bigint: true });
+        this.#store[file] = {
+          mtime: stat.mtimeMs,
+          size: Number(stat.size),
+          hash: hash ?? "",
+        };
+      } catch (e: any) {
+        if (e.code === "ENOENT") {
+          this.#store[file] = {
+            mtime: 0n,
+            size: 0,
+            hash: hash ?? "",
+          };
+        } else {
+          throw e;
+        }
+      }
       hashes[file] = hash ?? "";
     }
 

From f2cc661c9e60f17be45c4ade2c3d521300b4428f Mon Sep 17 00:00:00 2001
From: Elizabeth Craig <elcraig@microsoft.com>
Date: Thu, 9 Apr 2026 00:03:37 -0700
Subject: [PATCH 2/2] change file

---
 .../change-501f9623-19ff-418f-b70c-61580dd1343c.json  | 11 +++++++++++
 1 file changed, 11 insertions(+)
 create mode 100644 change/change-501f9623-19ff-418f-b70c-61580dd1343c.json

diff --git a/change/change-501f9623-19ff-418f-b70c-61580dd1343c.json b/change/change-501f9623-19ff-418f-b70c-61580dd1343c.json
new file mode 100644
index 000000000..dfea809e1
--- /dev/null
+++ b/change/change-501f9623-19ff-418f-b70c-61580dd1343c.json
@@ -0,0 +1,11 @@
+{
+  "changes": [
+    {
+      "type": "patch",
+      "comment": "Defend against missing files in the hashing logic",
+      "packageName": "@lage-run/hasher",
+      "email": "dobes@formative.com",
+      "dependentChangeType": "patch"
+    }
+  ]
+}
\ No newline at end of file