GROOVY-9381: Support async/await like ES7 #2324

daniellansun · 2025-10-26T14:57:54Z

https://issues.apache.org/jira/browse/GROOVY-9381

Copilot

Pull Request Overview

This PR implements ES7-like async/await functionality for Groovy, introducing new language keywords async and await along with supporting infrastructure for asynchronous programming.

Key Changes:

Added async and await as new language keywords in the Groovy parser and lexer
Implemented Promise-based asynchronous execution model with Promise, SimplePromise, and helper classes
Created AST transformation to convert async methods into Promise-returning methods

Reviewed Changes

Copilot reviewed 18 out of 18 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
src/antlr/GroovyLexer.g4	Adds ASYNC and AWAIT tokens to the lexer
src/antlr/GroovyParser.g4	Adds async modifier and await expression rules to grammar
src/main/java/org/apache/groovy/parser/antlr4/AstBuilder.java	Implements AST building for async/await expressions and method modifiers
src/main/java/org/apache/groovy/parser/antlr4/ModifierManager.java	Adds ASYNC to invalid modifiers list for constructors
src/main/java/org/codehaus/groovy/ast/ModifierNode.java	Registers ASYNC as virtual modifier with no JVM flag
src/main/java/org/codehaus/groovy/transform/AsyncASTTransformation.java	Implements transformation of async methods to return Promises
src/main/java/groovy/transform/Async.java	Defines @async annotation for marking async methods
src/main/java/groovy/util/concurrent/async/*.java	Core async infrastructure including Promise, Awaitable, AsyncHelper, and exception types
src/test/groovy/*/Test.groovy	Comprehensive test coverage for async/await functionality
src/test-resources/core/AsyncAwait_01x.groovy	Parser test case for async/await syntax

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2025-10-26T14:58:42Z

src/main/java/groovy/util/concurrent/async/Awaitable.java

+     * result.
+     *
+     * @return the computed result
+     * @throws AwaitException if the computation was cancelled or completed


The documentation for the await() method's exception is incomplete. It should state 'if the computation was cancelled or completed exceptionally' to clarify that exceptions are thrown on error conditions, not successful completion.

Suggested change

* @throws AwaitException if the computation was cancelled or completed

* @throws AwaitException if the computation was cancelled or completed exceptionally

codecov-commenter · 2025-10-26T15:30:26Z

Codecov Report

❌ Patch coverage is 75.82418% with 44 lines in your changes missing coverage. Please review.
✅ Project coverage is 67.0320%. Comparing base (4e0dc1a) to head (5e7e868).
⚠️ Report is 3 commits behind head on master.

Files with missing lines	Patch %	Lines
...va/groovy/util/concurrent/async/SimplePromise.java	83.3333%	16 Missing ⚠️
...java/groovy/util/concurrent/async/AsyncHelper.java	70.0000%	5 Missing and 1 partial ⚠️
...a/groovy/util/concurrent/async/AwaitException.java	25.0000%	6 Missing ⚠️
...ain/java/groovy/util/concurrent/async/Promise.java	0.0000%	5 Missing ⚠️
...a/groovy/util/concurrent/async/StageAwaitable.java	0.0000%	5 Missing ⚠️
...ehaus/groovy/transform/AsyncASTTransformation.java	80.9524%	2 Missing and 2 partials ⚠️
...va/org/apache/groovy/parser/antlr4/AstBuilder.java	88.8889%	1 Missing and 1 partial ⚠️

Additional details and impacted files

@@                Coverage Diff                 @@
##               master      #2324        +/-   ##
==================================================
+ Coverage     67.0088%   67.0320%   +0.0231%     
- Complexity      29326      29416        +90     
==================================================
  Files            1382       1388         +6     
  Lines          116604     116804       +200     
  Branches        20427      20446        +19     
==================================================
+ Hits            78135      78296       +161     
- Misses          32036      32069        +33     
- Partials         6433       6439         +6

Files with missing lines	Coverage Δ
...g/apache/groovy/parser/antlr4/ModifierManager.java	`93.4210% <100.0000%> (ø)`
...ain/java/org/codehaus/groovy/ast/ModifierNode.java	`77.7778% <100.0000%> (+0.4193%)`	⬆️
...va/org/codehaus/groovy/ast/tools/GeneralUtils.java	`86.0412% <100.0000%> (+0.1943%)`	⬆️
...va/org/apache/groovy/parser/antlr4/AstBuilder.java	`86.6667% <88.8889%> (+0.0444%)`	⬆️
...ehaus/groovy/transform/AsyncASTTransformation.java	`80.9524% <80.9524%> (ø)`
...ain/java/groovy/util/concurrent/async/Promise.java	`0.0000% <0.0000%> (ø)`
...a/groovy/util/concurrent/async/StageAwaitable.java	`0.0000% <0.0000%> (ø)`
...java/groovy/util/concurrent/async/AsyncHelper.java	`70.0000% <70.0000%> (ø)`
...a/groovy/util/concurrent/async/AwaitException.java	`25.0000% <25.0000%> (ø)`
...va/groovy/util/concurrent/async/SimplePromise.java	`83.3333% <83.3333%> (ø)`

... and 3 files with indirect coverage changes

🚀 New features to boost your workflow:

❄️ Test Analytics: Detect flaky tests, report on failures, and find test suite problems.
📦 JS Bundle Analysis: Save yourself from yourself by tracking and limiting bundle sizes in JS merges.

Copilot

Pull Request Overview

Copilot reviewed 18 out of 18 changed files in this pull request and generated 3 comments.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2025-10-26T18:34:31Z

src/main/java/groovy/util/concurrent/async/AsyncHelper.java

+ *
+ * @since 6.0.0
+ */
+public class AsyncHelper {


The system property 'groovy.async.parallelism' is not documented. Consider adding a comment explaining its purpose and valid values.

Suggested change

public class AsyncHelper {

public class AsyncHelper {

/**

* The system property "groovy.async.parallelism" controls the parallelism level

* (number of threads) used for the async thread pool. Valid values are positive integers.

* If not set, the default is (number of available processors + 1).

* Setting this value too high may lead to resource exhaustion; too low may reduce concurrency.

*/

Copilot · 2025-10-26T18:34:32Z

src/main/java/groovy/util/concurrent/async/AsyncHelper.java

+public class AsyncHelper {
+    private static final int PARALLELISM = SystemUtil.getIntegerSafe("groovy.async.parallelism", Runtime.getRuntime().availableProcessors() + 1);
+    private static final Executor DEFAULT_EXECUTOR;
+    private static int seq;


The static field seq is accessed from multiple threads without synchronization in the thread factory. Use AtomicInteger instead to prevent race conditions.

Copilot · 2025-10-26T18:34:32Z

src/antlr/GroovyLexer.g4

 WHILE         : 'while';
 YIELD         : 'yield';

+


[nitpick] Extra blank line added at line 490. Remove this unnecessary whitespace to maintain consistent formatting.

Suggested change

Copilot

Pull Request Overview

Copilot reviewed 21 out of 21 changed files in this pull request and generated 1 comment.

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

Copilot · 2025-10-27T16:56:18Z

src/main/java/org/apache/groovy/parser/antlr4/AstBuilder.java

+import static org.apache.groovy.parser.antlr4.GroovyParser.ADD;
+import static org.apache.groovy.parser.antlr4.GroovyParser.ARROW;
+import static org.apache.groovy.parser.antlr4.GroovyParser.AS;
+import static org.apache.groovy.parser.antlr4.GroovyParser.ASYNC;


[nitpick] The wildcard import at line 157 has been replaced with explicit imports. While this improves clarity by showing exactly which symbols are used, it significantly increases the number of import statements (158-362). Consider whether this trade-off between explicitness and verbosity aligns with the project's style guidelines.

daniellansun · 2025-10-27T16:58:30Z

@codecov-commenter

daniellansun requested a review from Copilot October 26, 2025 14:58

Copilot AI reviewed Oct 26, 2025

View reviewed changes

asf-gitbox-commits force-pushed the GROOVY-9381 branch from 73fe9eb to 208111a Compare October 26, 2025 15:05

asf-gitbox-commits force-pushed the GROOVY-9381 branch from 208111a to 8d4ea6f Compare October 26, 2025 18:32

daniellansun requested a review from Copilot October 26, 2025 18:33

Copilot AI reviewed Oct 26, 2025

View reviewed changes

asf-gitbox-commits force-pushed the GROOVY-9381 branch from 8d4ea6f to 1683f60 Compare October 27, 2025 16:54

daniellansun requested a review from Copilot October 27, 2025 16:55

Copilot AI reviewed Oct 27, 2025

View reviewed changes

asf-gitbox-commits force-pushed the GROOVY-9381 branch 3 times, most recently from 9ab2dee to 448d92a Compare October 27, 2025 18:10

daniellansun requested a review from Copilot October 27, 2025 18:10

This comment was marked as duplicate.

Sign in to view

asf-gitbox-commits force-pushed the GROOVY-9381 branch 2 times, most recently from dba9bf8 to e8d5ac1 Compare October 27, 2025 18:48

daniellansun requested a review from Copilot October 27, 2025 18:49

This comment was marked as duplicate.

Sign in to view

asf-gitbox-commits force-pushed the GROOVY-9381 branch 4 times, most recently from 71ef10c to 55d94fb Compare October 28, 2025 17:14

GROOVY-9381: Support async/await like ES7

5e7e868

asf-gitbox-commits force-pushed the GROOVY-9381 branch from 55d94fb to 5e7e868 Compare November 1, 2025 08:16

	* @throws AwaitException if the computation was cancelled or completed
	* @throws AwaitException if the computation was cancelled or completed exceptionally

-public class AsyncHelper {
+public class AsyncHelper {
+    /**
+     * The system property "groovy.async.parallelism" controls the parallelism level
+     * (number of threads) used for the async thread pool. Valid values are positive integers.
+     * If not set, the default is (number of available processors + 1).
+     * Setting this value too high may lead to resource exhaustion; too low may reduce concurrency.
+     */

GROOVY-9381: Support async/await like ES7 #2324

Are you sure you want to change the base?

GROOVY-9381: Support async/await like ES7 #2324

Uh oh!

Conversation

daniellansun commented Oct 26, 2025

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Reviewed Changes

Uh oh!

Copilot AI Oct 26, 2025

Choose a reason for hiding this comment

Uh oh!

codecov-commenter commented Oct 26, 2025 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Uh oh!

Copilot AI Oct 26, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Oct 26, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI Oct 26, 2025

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull Request Overview

Uh oh!

Copilot AI Oct 27, 2025

Choose a reason for hiding this comment

Uh oh!

daniellansun commented Oct 27, 2025

Uh oh!

This comment was marked as duplicate.

Uh oh!

This comment was marked as duplicate.

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

2 participants

codecov-commenter commented Oct 26, 2025 •

edited

Loading