Merge pull request #686 from cibernox/guard-against-undefined-processor

Add guards to check that `TaskQueue`s have at least one processor
orbitjs · Aug 20, 2019 · f19060b · f19060b
2 parents 11a1428 + 066e2bd
commit f19060b
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Showing 2 changed files with 56 additions and 2 deletions.
diff --git a/packages/@orbit/core/src/task-queue.ts b/packages/@orbit/core/src/task-queue.ts
@@ -218,7 +218,7 @@ export default class TaskQueue implements Evented {
         this._cancel();
         this._tasks.shift();
         let processor = this._processors.shift();
-        if (!processor.settled) {
+        if (processor !== undefined && !processor.settled) {
           processor.reject(
             e || new Error('Processing cancelled via `TaskQueue#skip`')
           );
@@ -262,7 +262,7 @@ export default class TaskQueue implements Evented {
         this._cancel();
         task = this._tasks.shift();
         let processor = this._processors.shift();
-        if (!processor.settled) {
+        if (processor !== undefined && !processor.settled) {
           processor.reject(
             e || new Error('Processing cancelled via `TaskQueue#shift`')
           );

diff --git a/packages/@orbit/core/test/task-queue-test.ts b/packages/@orbit/core/test/task-queue-test.ts
@@ -776,6 +776,33 @@ module('TaskQueue', function() {
     assert.equal(queue.length, 1, 'queue now has one member');
   });
 
+  test('#skip just restarts processing if there are no tasks in the queue', async function(assert) {
+    assert.expect(2);
+
+    const performer: Performer = {
+      async perform(task: Task): Promise<void> {}
+    };
+
+    const queue = new TaskQueue(performer, { autoProcess: true });
+
+    await queue.skip();
+
+    let op1 = { op: 'add', path: ['planets', '123'], value: 'Mercury' };
+
+    queue.on('complete', function() {
+      assert.ok(true, 'queue completed');
+    });
+
+    queue.on('task', function(task) {
+      assert.strictEqual(task.data, op1, 'op1 processed');
+    });
+
+    await queue.push({
+      type: 'transform',
+      data: op1
+    });
+  });
+
   test('#shift can remove failed tasks from an inactive queue, allowing processing to be restarted', async function(assert) {
     assert.expect(11);
 
@@ -961,6 +988,33 @@ module('TaskQueue', function() {
     assert.equal(queue.length, 1, 'queue now has one member');
   });
 
+  test('#shift just restarts processing if there are no tasks in the queue', async function(assert) {
+    assert.expect(2);
+
+    const performer: Performer = {
+      async perform(task: Task): Promise<void> {}
+    };
+
+    const queue = new TaskQueue(performer, { autoProcess: true });
+
+    await queue.shift();
+
+    let op1 = { op: 'add', path: ['planets', '123'], value: 'Mercury' };
+
+    queue.on('complete', function() {
+      assert.ok(true, 'queue completed');
+    });
+
+    queue.on('task', function(task) {
+      assert.strictEqual(task.data, op1, 'op1 processed');
+    });
+
+    await queue.push({
+      type: 'transform',
+      data: op1
+    });
+  });
+
   test('#unshift can add a new task to the beginning of an inactive queue', function(assert) {
     assert.expect(9);