fix: capture error stacks across async calls (#1088)

dev/src/bulk-writer.ts

@@ -21,7 +21,7 @@ import {RateLimiter} from './rate-limiter';
 import {DocumentReference} from './reference';
 import {Timestamp} from './timestamp';
 import {Precondition, SetOptions, UpdateData} from './types';
-import {Deferred} from './util';
+import {Deferred, wrapError} from './util';
 import {BatchWriteResult, WriteBatch, WriteResult} from './write-batch';
 
 /*!
@@ -188,7 +188,13 @@ class BulkCommitBatch {
       'The batch should be marked as READY_TO_SEND before committing'
     );
     this.state = BatchState.SENT;
-    return this.writeBatch.bulkCommit();
+
+    // Capture the error stack to preserve stack tracing across async calls.
+    const stack = Error().stack!;
+
+    return this.writeBatch.bulkCommit().catch(err => {
+      throw wrapError(err, stack);
+    });
   }
 
   /**

dev/src/index.ts

@@ -53,7 +53,7 @@ import {
   Settings,
   UnaryMethod,
 } from './types';
-import {Deferred, isPermanentRpcError, requestTag} from './util';
+import {Deferred, isPermanentRpcError, requestTag, wrapError} from './util';
 import {
   validateBoolean,
   validateFunction,
@@ -908,9 +908,15 @@ export class Firestore {
       documentRefsOrReadOptions
     );
     const tag = requestTag();
-    return this.initializeIfNeeded(tag).then(() =>
-      this.getAll_(documents, fieldMask, tag)
-    );
+
+    // Capture the error stack to preserve stack tracing across async calls.
+    const stack = Error().stack!;
+
+    return this.initializeIfNeeded(tag)
+      .then(() => this.getAll_(documents, fieldMask, tag))
+      .catch(err => {
+        throw wrapError(err, stack);
+      });
   }
 
   /**

dev/src/reference.ts

@@ -48,7 +48,7 @@ import {
   UpdateData,
   WhereFilterOp,
 } from './types';
-import {autoId, requestTag} from './util';
+import {autoId, requestTag, wrapError} from './util';
 import {
   invalidArgumentMessage,
   validateEnumValue,
@@ -1808,12 +1808,15 @@ export class Query<T = DocumentData> {
   _get(transactionId?: Uint8Array): Promise<QuerySnapshot<T>> {
     const docs: Array<QueryDocumentSnapshot<T>> = [];
 
+    // Capture the error stack to preserve stack tracing across async calls.
+    const stack = Error().stack!;
+
     return new Promise((resolve, reject) => {
       let readTime: Timestamp;
 
       this._stream(transactionId)
         .on('error', err => {
-          reject(err);
+          reject(wrapError(err, stack));
         })
         .on('data', result => {
           readTime = result.readTime;

dev/src/util.ts

@@ -146,3 +146,19 @@ export function isPermanentRpcError(
     return false;
   }
 }
+
+/**
+ * Wraps the provided error in a new error that includes the provided stack.
+ *
+ * Used to preserve stack traces across async calls.
+ * @private
+ */
+export function wrapError(err: Error | string, stack: string): Error {
+  // TODO(b/157506412): Remove `string` type and clean up any string errors
+  // that we are throwing.
+  if (typeof err === 'string') {
+    throw err;
+  }
+  err.stack += '\nCaused by: ' + stack;
+  return err;
+}

dev/src/write-batch.ts

@@ -37,7 +37,7 @@ import {
   UpdateMap,
 } from './types';
 import {DocumentData} from './types';
-import {isObject, isPlainObject, requestTag} from './util';
+import {isObject, isPlainObject, requestTag, wrapError} from './util';
 import {
   customObjectMessage,
   invalidArgumentMessage,
@@ -532,7 +532,12 @@ export class WriteBatch {
    * });
    */
   commit(): Promise<WriteResult[]> {
-    return this.commit_();
+    // Capture the error stack to preserve stack tracing across async calls.
+    const stack = Error().stack!;
+
+    return this.commit_().catch(err => {
+      throw wrapError(err, stack);
+    });
   }
 
   /**

dev/system-test/firestore.ts

@@ -2148,6 +2148,19 @@ describe('WriteBatch class', () => {
       });
   });
 
+  it('has a full stack trace if set() errors', () => {
+    // Use an invalid document name that the backend will reject.
+    const ref = randomCol.doc('__doc__');
+    const batch = firestore.batch();
+    batch.set(ref, {foo: 'a'});
+    return batch
+      .commit()
+      .then(() => Promise.reject('commit() should have failed'))
+      .catch((err: Error) => {
+        expect(err.stack).to.contain('WriteBatch.commit');
+      });
+  });
+
   it('has update() method', () => {
     const ref = randomCol.doc('doc');
     const batch = firestore.batch();