fix(task-gtaph): emit taskCancelled events

Emit taskCancelled events when dependants of failed tasks are cancelled.

This is a new event type.

garden-service/src/events.ts

@@ -84,6 +84,12 @@ export interface Events {
     key: string,
     version: ModuleVersion,
   },
+  taskCancelled: {
+    cancelledAt: Date,
+    type: string
+    key: string,
+    name: string,
+  },
   taskComplete: TaskResult,
   taskError: TaskResult,
   taskGraphProcessing: {

garden-service/src/task-graph.ts

@@ -283,8 +283,15 @@ export class TaskGraph {
 
   // Recursively remove node's dependants, without removing node.
   private cancelDependants(node: TaskNode) {
+    const cancelledAt = new Date()
     for (const dependant of this.getDependants(node)) {
       this.logTaskComplete(dependant, false)
+      this.garden.events.emit("taskCancelled", {
+        cancelledAt,
+        key: dependant.getKey(),
+        name: dependant.task.getName(),
+        type: dependant.getType(),
+      })
       this.remove(dependant)
     }
     this.rebuild()

garden-service/test/unit/src/task-graph.ts

@@ -5,6 +5,7 @@ import { BaseTask, TaskType } from "../../../src/tasks/base"
 import { TaskGraph, TaskResult, TaskResults } from "../../../src/task-graph"
 import { makeTestGarden, freezeTime, dataDir, defer } from "../../helpers"
 import { Garden } from "../../../src/garden"
+import { deepFilter } from "../../../src/util/util"
 
 const projectRoot = join(dataDir, "test-project-empty")
 
@@ -18,6 +19,12 @@ interface TestTaskOptions {
   throwError?: boolean
 }
 
+const testTaskVersion = {
+  versionString: "12345-6789",
+  dependencyVersions: {},
+  files: [],
+}
+
 class TestTask extends BaseTask {
   type: TaskType = "test"
   name: string
@@ -381,9 +388,36 @@ describe("task-graph", () => {
         dependencyResults: {},
       }
 
+      const filteredKeys: Set<string | number> = new Set([
+        "version", "error", "addedAt", "startedAt", "cancelledAt", "completedAt"])
+
+      const filteredEventLog = garden.events.eventLog.map(e => {
+        return deepFilter(e, (_, key) => !filteredKeys.has(key))
+      })
+
       expect(results.a).to.eql(resultA)
       expect(results.b).to.have.property("error")
       expect(resultOrder).to.eql(["a", "b"])
+      expect(filteredEventLog).to.eql([
+        { name: "taskPending", payload: { key: "a" } },
+        { name: "taskPending", payload: { key: "b" } },
+        { name: "taskPending", payload: { key: "c" } },
+        { name: "taskPending", payload: { key: "d" } },
+        { name: "taskGraphProcessing", payload: {} },
+        { name: "taskProcessing", payload: { key: "a" } },
+        {
+          name: "taskComplete", payload: {
+            dependencyResults: {}, description: "a", key: "a", name: "a",
+            output: { dependencyResults: {}, result: "result-a" }, type: "test",
+          },
+        },
+        { name: "taskProcessing", payload: { key: "b" } },
+        { name: "taskError", payload: { description: "b", key: "b", name: "b", type: "test" } },
+        { name: "taskCancelled", payload: { key: "c", name: "c", type: "test" } },
+        { name: "taskCancelled", payload: { key: "d", name: "d", type: "test" } },
+        { name: "taskCancelled", payload: { key: "d", name: "d", type: "test" } },
+        { name: "taskGraphComplete", payload: {} },
+      ])
     })
 
   })