Add blog post.

nextgen/task-builder/src/tasks_builder.rs

@@ -16,6 +16,21 @@ use std::hash::Hash;
 use std::path::Path;
 use tracing::trace;
 
+// This is a standalone function as recursive closures are not possible!
+fn extract_config<'builder, 'proj>(
+    task_id: &'builder Id,
+    tasks_map: &'builder FxHashMap<&'proj Id, &'proj TaskConfig>,
+    configs: &'builder mut Vec<&'proj TaskConfig>,
+) {
+    if let Some(config) = tasks_map.get(task_id) {
+        if let Some(extend_task_id) = &config.extends {
+            extract_config(extend_task_id, tasks_map, configs);
+        }
+
+        configs.push(*config);
+    }
+}
+
 #[derive(Debug)]
 pub struct DetectPlatformEvent {
     pub enabled_platforms: Vec<PlatformType>,
@@ -529,25 +544,8 @@ impl<'proj> TasksBuilder<'proj> {
     fn get_config_inherit_chain(&self, id: &Id) -> Vec<&TaskConfig> {
         let mut configs = vec![];
 
-        if let Some(config) = self.global_tasks.get(id) {
-            if let Some(extends_from) = &config.extends {
-                if let Some(extends_config) = self.global_tasks.get(extends_from) {
-                    configs.push(*extends_config);
-                }
-            }
-
-            configs.push(*config);
-        }
-
-        if let Some(config) = self.local_tasks.get(id) {
-            if let Some(extends_from) = &config.extends {
-                if let Some(extends_config) = self.local_tasks.get(extends_from) {
-                    configs.push(*extends_config);
-                }
-            }
-
-            configs.push(*config);
-        }
+        extract_config(id, &self.global_tasks, &mut configs);
+        extract_config(id, &self.local_tasks, &mut configs);
 
         configs
     }

nextgen/task-builder/tests/__fixtures__/builder/extends/moon.yml

@@ -13,6 +13,12 @@ tasks:
     options:
       mergeArgs: prepend
 
+  extend-args-again:
+    extends: extend-args
+    args: --bail
+    options:
+      mergeArgs: append
+
   extend-inputs:
     extends: base
     inputs:

nextgen/task-builder/tests/tasks_builder_test.rs

@@ -1197,5 +1197,15 @@ mod tasks_builder {
             assert!(task.options.persistent);
             assert_eq!(task.options.retry_count, 3);
         }
+
+        #[tokio::test]
+        async fn can_create_extends_chains() {
+            let sandbox = create_sandbox("builder");
+            let tasks = build_tasks(sandbox.path(), "extends/moon.yml").await;
+            let task = tasks.get("extend-args-again").unwrap();
+
+            assert_eq!(task.command, "lint");
+            assert_eq!(task.args, vec!["./src", "--fix", "--bail"]);
+        }
     }
 }

packages/cli/CHANGELOG.md

@@ -1,5 +1,12 @@
 # Changelog
 
+## Unreleased
+
+#### 🚀 Updates
+
+- Added an `extends` field to task configurations. This allows tasks to extend and inherit settings
+  from sibling tasks.
+
 ## 1.11.1
 
 #### 🐞 Fixes

packages/types/src/tasks-config.ts

@@ -39,6 +39,7 @@ export interface PartialTaskConfig {
 	command?: PartialTaskCommandArgs | null;
 	deps?: string[] | null;
 	env?: Record<string, string> | null;
+	extends?: string | null;
 	inputs?: string[] | null;
 	local?: boolean | null;
 	options?: PartialTaskOptionsConfig | null;
@@ -82,6 +83,7 @@ export interface TaskConfig {
 	command: TaskCommandArgs;
 	deps: string[];
 	env: Record<string, string>;
+	extends: string | null;
 	inputs: string[] | null;
 	local: boolean | null;
 	options: TaskOptionsConfig;

website/blog/2023-08-21_moon-v1.12.mdx

@@ -0,0 +1,92 @@
+---
+slug: moon-v1.12
+title: moon v1.12 - Task extending
+authors: [milesj]
+tags: [tasks, inheritance]
+# image: ./img/moon/v1.11.png
+---
+
+???
+
+<!--truncate-->
+
+## Extending sibling or inherited tasks
+
+Three months ago, we posted an
+[RFC on how to support task extending / task variants](https://github.com/moonrepo/moon/issues/849).
+On paper this doesn't sound like a hard problem to solve, but internally it would of been an uphill
+battle to implement. Thanks to previous releases from the past few months, and the rewrite of the
+project graph, task builder, and more, this implementation was a breeze. To finalize the RFC, we
+went with option 2, by adding a new `extends` field to task configurations.
+
+With this new addition, we can now rewrite this old configuration, which was needlessly
+repetitive...
+
+```yaml title="moon.yml"
+tasks:
+  lint:
+    command: 'eslint .'
+    inputs:
+      - '@globs(sources)'
+      - '@globs(tests)'
+      - '*.js'
+      - '.eslintrc.js'
+      - 'tsconfig.json'
+      - '/.eslintignore'
+      - '/.eslintrc.js'
+      - '/tsconfig.eslint.json'
+      - '/tsconfig.options.json'
+
+  lint-fix:
+    command: 'eslint . --fix'
+    local: true
+    inputs:
+      - '@globs(sources)'
+      - '@globs(tests)'
+      - '*.js'
+      - '.eslintrc.js'
+      - 'tsconfig.json'
+      - '/.eslintignore'
+      - '/.eslintrc.js'
+      - '/tsconfig.eslint.json'
+      - '/tsconfig.options.json'
+```
+
+Into the following configuration.
+
+```yaml title="moon.yml"
+tasks:
+  lint:
+    command: 'eslint .'
+    inputs:
+      - '@globs(sources)'
+      - '@globs(tests)'
+      - '*.js'
+      - '.eslintrc.js'
+      - 'tsconfig.json'
+      - '/.eslintignore'
+      - '/.eslintrc.js'
+      - '/tsconfig.eslint.json'
+      - '/tsconfig.options.json'
+
+  lint-fix:
+    extends: 'lint'
+    args: '--fix'
+    local: true
+```
+
+We're very happy with this solution, as it's far more readable, maintainable, and doesn't introduce
+yet another paradigm to learn. Our goal was to be as familiar as possible, while providing extensive
+functionality behind the scenes, which we believe to have achieved.
+
+Some other interesting facts around task extending:
+
+- When extending a task, [merge strategies](/docs/concepts/task#merge-strategies) are applied in a
+  similar fashion to inheritance.
+- Inherited tasks can be extended from by project-level tasks.
+- It's possible to create multiple extended chains.
+
+## Other changes
+
+View the [official release](https://github.com/moonrepo/moon/releases/tag/v1.12.0) for a full list
+of changes.

website/docs/config/project.mdx

@@ -350,6 +350,30 @@ tasks:
     command: 'tsc'
 ```
 
+### `extends`<VersionLabel version="1.12.0" />
+
+<HeadingApiLink to="/api/types/interface/TaskConfig#extends" />
+
+The `extends` field can be used to extend the settings from a sibling task within the same project,
+or [inherited from the global scope](../concepts/task#inheritance). This is useful for composing
+similar tasks with different arguments or options.
+
+When extending another task, the same [merge strategies](../concepts/task#merge-strategies) used for
+inheritance are applied.
+
+```yaml title="moon.yml"
+tasks:
+  lint:
+    command: 'eslint .'
+    inputs:
+      - 'src/**/*'
+
+  lint-fix:
+    extends: 'lint'
+    args: '--fix'
+    local: true
+```
+
 ### `command`<RequiredLabel />
 
 <HeadingApiLink to="/api/types/interface/TaskConfig#command" />

website/static/schemas/project.json

@@ -641,6 +641,16 @@
             }
           ]
         },
+        "extends": {
+          "anyOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
         "inputs": {
           "anyOf": [
             {

website/static/schemas/tasks.json

@@ -159,6 +159,16 @@
             }
           ]
         },
+        "extends": {
+          "anyOf": [
+            {
+              "type": "string"
+            },
+            {
+              "type": "null"
+            }
+          ]
+        },
         "inputs": {
           "anyOf": [
             {