Add concurrency queue support (#355)

workflow-parser/src/model/converter/concurrency.ts

@@ -1,10 +1,12 @@
+import type {FeatureFlags} from "@actions/expressions/features";
 import {TemplateContext} from "../../templates/template-context.js";
 import {TemplateToken} from "../../templates/tokens/template-token.js";
 import {isString} from "../../templates/tokens/type-guards.js";
-import {ConcurrencySetting} from "../workflow-template.js";
+import {ConcurrencyQueue, ConcurrencySetting} from "../workflow-template.js";
 
 export function convertConcurrency(context: TemplateContext, token: TemplateToken): ConcurrencySetting {
   const result: ConcurrencySetting = {};
+  const featureFlags = context.state.featureFlags as FeatureFlags | undefined;
 
   if (token.isExpression) {
     return result;
@@ -26,6 +28,11 @@ export function convertConcurrency(context: TemplateContext, token: TemplateToke
       case "cancel-in-progress":
         result.cancelInProgress = property.value.assertBoolean("cancel-in-progress").value;
         break;
+      case "queue":
+        if (featureFlags?.isEnabled("allowConcurrencyQueue")) {
+          result.queue = property.value.assertString("queue").value as ConcurrencyQueue;
+        }
+        break;
       default:
         context.error(propertyName, `Invalid property name: ${propertyName.value}`);
     }

workflow-parser/src/model/workflow-template.ts

@@ -18,9 +18,12 @@ export type WorkflowTemplate = {
   }[];
 };
 
+export type ConcurrencyQueue = "single" | "max";
+
 export type ConcurrencySetting = {
   group?: StringToken;
   cancelInProgress?: boolean;
+  queue?: ConcurrencyQueue;
 };
 
 export type ActionsEnvironmentReference = {

workflow-parser/src/workflow-v1.0.json

@@ -2050,10 +2050,20 @@
           "cancel-in-progress": {
             "type": "boolean",
             "description": "To cancel any currently running job or workflow in the same concurrency group, specify cancel-in-progress: true."
+          },
+          "queue": {
+            "type": "concurrency-queue",
+            "description": "The queuing mode for the concurrency group. When set to `max`, workflows or jobs will wait in a queue for the concurrency group up to the maximum queue length. Default: `single` meaning at most one item can be pending."
           }
         }
       }
     },
+    "concurrency-queue": {
+      "allowed-values": [
+        "single",
+        "max"
+      ]
+    },
     "job-environment": {
       "description": "The environment that the job references. All environment protection rules must pass before a job referencing the environment is sent to a runner.",
       "context": [