Return BlobNotFound for conditional reads of missing blobs

ChangeLog.md

@@ -13,6 +13,7 @@ General:
 
 Blob:
 
+- Fixed Blob GET and HEAD requests for nonexistent blobs with `If-Match` so they now return `BlobNotFound` instead of `ConditionNotMet`, matching Azure Storage. (issue #2751)
 - Fixed block blob uploads with `If-None-Match: *` returning `BlobAlreadyExists` before validating an active lease, matching Azure Storage's `LeaseIdMissing` and lease mismatch error precedence. (issue #2637)
 - Fixed service- and container-level Filter Blobs requests failing when the optional `where` query parameter is omitted.
 - Fixed blob operations hanging when a client disconnects before the operation queue processes the request. (issue #2575)

src/blob/persistence/LokiBlobMetadataStore.ts

@@ -1206,12 +1206,12 @@ export default class LokiBlobMetadataStore
       true
     );
 
-    validateReadConditions(context, modifiedAccessConditions, doc);
-
     if (!doc) {
       throw StorageErrorFactory.getBlobNotFound(context.contextId);
     }
 
+    validateReadConditions(context, modifiedAccessConditions, doc);
+
     new BlobReadLeaseValidator(leaseAccessConditions).validate(
       new BlobLeaseAdapter(doc),
       context
@@ -1289,13 +1289,13 @@ export default class LokiBlobMetadataStore
       true
     );
 
-    validateReadConditions(context, modifiedAccessConditions, doc);
-
     // When block blob don't have committed block, should return 404
     if (!doc) {
       throw StorageErrorFactory.getBlobNotFound(context.contextId);
     }
 
+    validateReadConditions(context, modifiedAccessConditions, doc);
+
     new BlobReadLeaseValidator(leaseAccessConditions).validate(
       new BlobLeaseAdapter(doc),
       context

src/blob/persistence/SqlBlobMetadataStore.ts

@@ -1188,14 +1188,6 @@ export default class SqlBlobMetadataStore implements IBlobMetadataStore {
         transaction: t
       });
 
-      validateReadConditions(
-        context,
-        modifiedAccessConditions,
-        blobFindResult
-          ? this.convertDbModelToBlobModel(blobFindResult)
-          : undefined
-      );
-
       if (blobFindResult === null || blobFindResult === undefined) {
         throw StorageErrorFactory.getBlobNotFound(context.contextId);
       }
@@ -1204,6 +1196,8 @@ export default class SqlBlobMetadataStore implements IBlobMetadataStore {
         blobFindResult
       );
 
+      validateReadConditions(context, modifiedAccessConditions, blobModel);
+
       return LeaseFactory.createLeaseState(
         new BlobLeaseAdapter(blobModel),
         context
@@ -1790,14 +1784,6 @@ export default class SqlBlobMetadataStore implements IBlobMetadataStore {
         transaction: t
       });
 
-      validateReadConditions(
-        context,
-        modifiedAccessConditions,
-        blobFindResult
-          ? this.convertDbModelToBlobModel(blobFindResult)
-          : undefined
-      );
-
       if (blobFindResult === null || blobFindResult === undefined) {
         throw StorageErrorFactory.getBlobNotFound(context.contextId);
       }
@@ -1810,6 +1796,8 @@ export default class SqlBlobMetadataStore implements IBlobMetadataStore {
         throw StorageErrorFactory.getBlobNotFound(context.contextId);
       }
 
+      validateReadConditions(context, modifiedAccessConditions, blobModel);
+
       // TODO: Return blobCommittedBlockCount for append blob
 
       let responds = LeaseFactory.createLeaseState(

tests/blob/apis/blob.test.ts

@@ -214,6 +214,46 @@ describe("BlobAPIs", () => {
     assert.fail();
   });
 
+  it("download should return BlobNotFound for nonexistent blob with ifMatch @loki @sql", async () => {
+    const properties = await blobClient.getProperties();
+    const nonExistentBlobClient = containerClient.getBlobClient(
+      getUniqueName("missingblob")
+    );
+
+    try {
+      await nonExistentBlobClient.download(0, undefined, {
+        conditions: {
+          ifMatch: properties.etag
+        }
+      });
+    } catch (error) {
+      assert.deepStrictEqual((error as any).statusCode, 404);
+      assert.deepStrictEqual((error as any).details.errorCode, "BlobNotFound");
+      return;
+    }
+    assert.fail();
+  });
+
+  it("getProperties should return BlobNotFound for nonexistent blob with ifMatch @loki @sql", async () => {
+    const properties = await blobClient.getProperties();
+    const nonExistentBlobClient = containerClient.getBlobClient(
+      getUniqueName("missingblob")
+    );
+
+    try {
+      await nonExistentBlobClient.getProperties({
+        conditions: {
+          ifMatch: properties.etag
+        }
+      });
+    } catch (error) {
+      assert.deepStrictEqual((error as any).statusCode, 404);
+      assert.deepStrictEqual((error as any).details.errorCode, "BlobNotFound");
+      return;
+    }
+    assert.fail();
+  });
+
   it("download should not work with conditional header ifNoneMatch @loki @sql", async () => {
     const properties = await blobClient.getProperties();
     try {