fix: always close gridfs upload stream on finish

Author: durran

.evergreen/config.yml

@@ -1225,6 +1225,12 @@ buildvariants:
     expansions:
       NODE_LTS_NAME: erbium
     tasks: *ref_0
+  - name: macos-1014-fermium
+    display_name: macOS 10.14 Node Fermium
+    run_on: macos-1014
+    expansions:
+      NODE_LTS_NAME: fermium
+    tasks: *ref_0
   - name: rhel70-dubnium
     display_name: RHEL 7.0 Node Dubnium
     run_on: rhel70-small
@@ -1291,6 +1297,12 @@ buildvariants:
     expansions:
       NODE_LTS_NAME: erbium
     tasks: *ref_1
+  - name: rhel70-fermium
+    display_name: RHEL 7.0 Node Fermium
+    run_on: rhel70-small
+    expansions:
+      NODE_LTS_NAME: fermium
+    tasks: *ref_1
   - name: ubuntu-14.04-dubnium
     display_name: Ubuntu 14.04 Node Dubnium
     run_on: ubuntu1404-large
@@ -1325,6 +1337,12 @@ buildvariants:
     expansions:
       NODE_LTS_NAME: erbium
     tasks: *ref_2
+  - name: ubuntu-14.04-fermium
+    display_name: Ubuntu 14.04 Node Fermium
+    run_on: ubuntu1404-large
+    expansions:
+      NODE_LTS_NAME: fermium
+    tasks: *ref_2
   - name: ubuntu-18.04-dubnium
     display_name: Ubuntu 18.04 Node Dubnium
     run_on: ubuntu1804-large
@@ -1387,6 +1405,13 @@ buildvariants:
       NODE_LTS_NAME: erbium
       CLIENT_ENCRYPTION: true
     tasks: *ref_3
+  - name: ubuntu-18.04-fermium
+    display_name: Ubuntu 18.04 Node Fermium
+    run_on: ubuntu1804-large
+    expansions:
+      NODE_LTS_NAME: fermium
+      CLIENT_ENCRYPTION: true
+    tasks: *ref_3
   - name: windows-64-vs2015-dubnium
     display_name: Windows (VS2015) Node Dubnium
     run_on: windows-64-vs2015-large
@@ -1424,6 +1449,13 @@ buildvariants:
       NODE_LTS_NAME: erbium
       MSVS_VERSION: 2015
     tasks: *ref_4
+  - name: windows-64-vs2015-fermium
+    display_name: Windows (VS2015) Node Fermium
+    run_on: windows-64-vs2015-large
+    expansions:
+      NODE_LTS_NAME: fermium
+      MSVS_VERSION: 2015
+    tasks: *ref_4
   - name: windows-64-vs2017-dubnium
     display_name: Windows (VS2017) Node Dubnium
     run_on: windows-64-vs2017-large

src/gridfs-stream/upload.ts

@@ -67,6 +67,8 @@ export class GridFSBucketWriteStream extends Writable {
   };
   writeConcern?: WriteConcern;
 
+  /** @event */
+  static readonly CLOSE = 'close';
   /** @event */
   static readonly ERROR = 'error';
   /**
@@ -325,6 +327,7 @@ function checkDone(stream: GridFSBucketWriteStream, callback?: Callback): boolea
         return __handleError(stream, error, callback);
       }
       stream.emit(GridFSBucketWriteStream.FINISH, filesDoc);
+      stream.emit(GridFSBucketWriteStream.CLOSE);
     });
 
     return true;