feat(core): introduce continuous tasks (#29750)

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## Summary

An RFC about this feature is happening here: #29025. This has the most
information about this feature.

## Current Behavior
<!-- This is the behavior we have today -->

Nx currently does not explicitly handle tasks which run continuously
until they are terminated.

## Expected Behavior
<!-- This is the behavior we should expect with the changes in this PR
-->

This PR adds the initial support for continuous tasks which run
continuously until they are terminated. This adds the ability to depend
on continuous tasks. There is some more work to be done but this will be
enough as an MVP.

## Related Issue(s)
<!-- Please link the issue being fixed so it gets closed when this is
merged. -->

Fixes #

Author: FrozenPandaz

docs/generated/devkit/TargetConfiguration.md

@@ -15,6 +15,7 @@ Target's configuration
 - [cache](../../devkit/documents/TargetConfiguration#cache): boolean
 - [command](../../devkit/documents/TargetConfiguration#command): string
 - [configurations](../../devkit/documents/TargetConfiguration#configurations): Object
+- [continuous](../../devkit/documents/TargetConfiguration#continuous): boolean
 - [defaultConfiguration](../../devkit/documents/TargetConfiguration#defaultconfiguration): string
 - [dependsOn](../../devkit/documents/TargetConfiguration#dependson): (string | TargetDependencyConfig)[]
 - [executor](../../devkit/documents/TargetConfiguration#executor): string
@@ -55,6 +56,14 @@ Sets of options
 
 ---
 
+### continuous
+
+• `Optional` **continuous**: `boolean`
+
+Whether this target runs continuously
+
+---
+
 ### defaultConfiguration
 
 • `Optional` **defaultConfiguration**: `string`

docs/generated/devkit/Task.md

@@ -7,6 +7,7 @@ A representation of the invocation of an Executor
 ### Properties
 
 - [cache](../../devkit/documents/Task#cache): boolean
+- [continuous](../../devkit/documents/Task#continuous): boolean
 - [endTime](../../devkit/documents/Task#endtime): number
 - [hash](../../devkit/documents/Task#hash): string
 - [hashDetails](../../devkit/documents/Task#hashdetails): Object
@@ -28,6 +29,14 @@ Determines if a given task should be cacheable.
 
 ---
 
+### continuous
+
+• `Optional` **continuous**: `boolean`
+
+This denotes if the task runs continuously
+
+---
+
 ### endTime
 
 • `Optional` **endTime**: `number`

docs/generated/devkit/TaskGraph.md

@@ -6,12 +6,19 @@ Graph of Tasks to be executed
 
 ### Properties
 
+- [continuousDependencies](../../devkit/documents/TaskGraph#continuousdependencies): Record<string, string[]>
 - [dependencies](../../devkit/documents/TaskGraph#dependencies): Record<string, string[]>
 - [roots](../../devkit/documents/TaskGraph#roots): string[]
 - [tasks](../../devkit/documents/TaskGraph#tasks): Record<string, Task>
 
 ## Properties
 
+### continuousDependencies
+
+• **continuousDependencies**: `Record`\<`string`, `string`[]\>
+
+---
+
 ### dependencies
 
 • **dependencies**: `Record`\<`string`, `string`[]\>

packages/js/src/utils/buildable-libs-utils.spec.ts

@@ -394,6 +394,7 @@ describe('calculateDependenciesFromTaskGraph', () => {
         'lib3:build': [],
         'lib4:build': [],
       },
+      continuousDependencies: {},
       roots: [],
       tasks: {
         'lib1:build': {
@@ -402,34 +403,39 @@ describe('calculateDependenciesFromTaskGraph', () => {
           target: { project: 'lib1', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib2:build': {
           id: 'lib2:build',
           overrides: {},
           target: { project: 'lib2', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib2:build-base': {
           id: 'lib2:build-base',
           overrides: {},
           target: { project: 'lib2', target: 'build-base' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib3:build': {
           id: 'lib3:build',
           overrides: {},
           target: { project: 'lib3', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib4:build': {
           id: 'lib4:build',
           overrides: {},
           target: { project: 'lib4', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
       },
     };
@@ -569,6 +575,7 @@ describe('calculateDependenciesFromTaskGraph', () => {
         'lib4:build': ['lib4:build-base'],
         'lib4:build-base': [],
       },
+      continuousDependencies: {},
       roots: [],
       tasks: {
         'lib1:build': {
@@ -577,55 +584,63 @@ describe('calculateDependenciesFromTaskGraph', () => {
           target: { project: 'lib1', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib1:build-base': {
           id: 'lib1:build-base',
           overrides: {},
           target: { project: 'lib1', target: 'build-base' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib2:build': {
           id: 'lib2:build',
           overrides: {},
           target: { project: 'lib2', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib2:build-base': {
           id: 'lib2:build-base',
           overrides: {},
           target: { project: 'lib2', target: 'build-base' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib3:build': {
           id: 'lib3:build',
           overrides: {},
           target: { project: 'lib3', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib3:build-base': {
           id: 'lib3:build-base',
           overrides: {},
           target: { project: 'lib3', target: 'build-base' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib4:build': {
           id: 'lib4:build',
           overrides: {},
           target: { project: 'lib4', target: 'build' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
         'lib4:build-base': {
           id: 'lib4:build-base',
           overrides: {},
           target: { project: 'lib4', target: 'build-base' },
           outputs: [],
           parallelism: true,
+          continuous: false,
         },
       },
     };
@@ -717,6 +732,7 @@ describe('calculateDependenciesFromTaskGraph', () => {
     // not relevant for this test case
     const taskGraph: TaskGraph = {
       dependencies: {},
+      continuousDependencies: {},
       roots: [],
       tasks: {},
     };

packages/nx/package.json

@@ -66,6 +66,7 @@
     "string-width": "^4.2.3",
     "tar-stream": "~2.2.0",
     "tmp": "~0.2.1",
+    "tree-kill": "^1.2.2",
     "tsconfig-paths": "^4.1.2",
     "tslib": "^2.3.0",
     "yaml": "^2.6.0",

packages/nx/src/command-line/graph/graph.ts

@@ -980,6 +980,7 @@ function getAllTaskGraphsForWorkspace(projectGraph: ProjectGraph): {
         taskGraphs[taskId] = {
           tasks: {},
           dependencies: {},
+          continuousDependencies: {},
           roots: [],
         };
 
@@ -1006,6 +1007,7 @@ function getAllTaskGraphsForWorkspace(projectGraph: ProjectGraph): {
             taskGraphs[taskId] = {
               tasks: {},
               dependencies: {},
+              continuousDependencies: {},
               roots: [],
             };
 

packages/nx/src/commands-runner/get-command-projects.ts

@@ -1,5 +1,4 @@
 import { ProjectGraph, ProjectGraphProjectNode } from '../config/project-graph';
-import { removeIdsFromGraph } from '../tasks-runner/utils';
 import { NxArgs } from '../utils/command-line-utils';
 import { CommandGraph } from './command-graph';
 import { createCommandGraph } from './create-command-graph';
@@ -34,3 +33,35 @@ function getSortedProjects(
 
   return getSortedProjects(newGraph, sortedProjects);
 }
+
+function removeIdsFromGraph<T>(
+  graph: {
+    roots: string[];
+    dependencies: Record<string, string[]>;
+  },
+  ids: string[],
+  mapWithIds: Record<string, T>
+): {
+  mapWithIds: Record<string, T>;
+  roots: string[];
+  dependencies: Record<string, string[]>;
+} {
+  const filteredMapWithIds = {};
+  const dependencies = {};
+  const removedSet = new Set(ids);
+  for (let id of Object.keys(mapWithIds)) {
+    if (!removedSet.has(id)) {
+      filteredMapWithIds[id] = mapWithIds[id];
+      dependencies[id] = graph.dependencies[id].filter(
+        (depId) => !removedSet.has(depId)
+      );
+    }
+  }
+  return {
+    mapWithIds: filteredMapWithIds,
+    dependencies: dependencies,
+    roots: Object.keys(dependencies).filter(
+      (k) => dependencies[k].length === 0
+    ),
+  };
+}

packages/nx/src/config/task-graph.ts

@@ -81,6 +81,11 @@ export interface Task {
    * Determines if a given task should be parallelizable.
    */
   parallelism: boolean;
+
+  /**
+   * This denotes if the task runs continuously
+   */
+  continuous?: boolean;
 }
 
 /**
@@ -99,4 +104,6 @@ export interface TaskGraph {
    * Map of Task IDs to IDs of tasks which the task depends on
    */
   dependencies: Record<string, string[]>;
+
+  continuousDependencies: Record<string, string[]>;
 }

packages/nx/src/config/workspace-json-project-json.ts

@@ -258,6 +258,11 @@ export interface TargetConfiguration<T = any> {
    */
   parallelism?: boolean;
 
+  /**
+   * Whether this target runs continuously
+   */
+  continuous?: boolean;
+
   /**
    * List of generators to run before the target to ensure the workspace
    * is up to date.